PTC Creo Elements/Pro

Creo Parametric, formerly known, together with Creo Elements/Pro, as Pro/Engineer and Wildfire, is a solid modeling or CAD, CAM, CAE, and associative 3D modeling application, running on Microsoft Windows.
Creo Parametric should not to be confused with Creo Elements/Direct Modeling, which was CoCreate ME10 (2D) and or ME30 (3D) CAD Products. The ex-CoCreate CAD Products are now owned by PTC and offered as "Creo Elements/Direct Drafting" and Creo Elements/Direct Modling".
Creo Parametric is an application of a suite of 10 that provide collaborative solid modeling, assembly modeling, 2D orthographic views, finite element analysis, parametric modeling, sub-divisional and NURBS surface modeling, Drafting, and NC and tooling functionality for mechanical designers.
Creo Elements/Pro compete directly with CATIA, SolidWorks, NX/Solid Edge, Inventor/Fusion 360, IRONCAD, and Onshape. It was created by Parametric Technology Corporation (PTC) and was the first of its kind to market.
The software uses a specific file naming scheme, not allowing certain characters (including spaces).
Overview.
Creo Elements (formerly Pro/Engineer), PTC's parametric, integrated 3D CAD/CAM/CAE solution, is used by manufacturers for mechanical engineering, design and manufacturing.
Pro/Engineer was the industry's first rule-based constraint (sometimes called "parametric" or "variational") 3D CAD modeling system. The parametric modeling approach uses parameters, dimensions, features, and relationships to capture intended model behavior. This design approach can be family-based or platform-driven, where the strategy is to use engineering constraints and relationships to quickly optimize the design, or where the resulting geometry may be complex or based upon equations. Creo Elements provides a complete set of design, analysis and manufacturing capabilities on one, integral, scalable platform. These required capabilities include Solid Modeling, Surfacing, Rendering, Data Interoperability, Routed Systems Design, Simulation, Tolerance Analysis, and NC and Tooling Design.
Creo Elements can be used to create a complete 3D digital model of manufactured goods. The models consist of 2D and 3D solid model data which can also be used downstream in finite element analysis, rapid prototyping, tooling design, and CNC manufacturing. All data are associative and interchangeable between the CAD, CAE and CAM modules without conversion. A product and its entire bill of materials (BOM) can be modeled accurately with fully associative engineering drawings, and revision control information. The associativity functionality in Creo Elements enables users to make changes in the design at any time during the product development process and automatically update the end products. This capability enables concurrent engineering – design, analysis and manufacturing engineers working in parallel – and streamlines product development processes.
Summary of capabilities.
Creo Elements is a software application within the CAID/CAD/CAM/CAE category.
Creo Elements is a parametric, feature-based modeling architecture incorporated into a single database philosophy with rule-based design capabilities. It provides in-depth control of complex geometry. The capabilities of the product can be split into the three main headings of Engineering Design, Analysis and Manufacturing. This data is then documented in a standard 2D production drawing or the 3D drawing standard ASME Y14.41-2003.
Product Design.
Creo Elements offers a range of tools to enable the generation of a complete digital representation of the product being designed. In addition to the general geometry tools there is also the ability to generate geometry of other integrated design disciplines such as industrial and standard pipe work and complete wiring definitions. Tools are also available to support collaborative development.
A number of concept design tools that provide up-front Industrial Design concepts can then be used in the downstream process of engineering the product. These range from conceptual Industrial design sketches, reverse engineering with point cloud data and comprehensive free-form surface.
Analysis.
Creo Elements has numerous analysis tools available and covers thermal, static, dynamic and fatigue finite element analysis along with other tools all designed to help with the development of the product. These tools include human factors, manufacturing tolerance, mould flow and design optimization. The design optimization can be used at a geometry level to obtain the optimum design dimensions and in conjunction with the finite element analysis.
Surface Modeling.
Creo has a good surface modeling capabilities also. Using commands like Boundary blend and Sweep we can create surface models. Advance options like Style (Interactive Surface Design Extension - ISDX) and Freestyle provide more capabilities to designer to create complicated models with ease.
Manufacturing
By using the fundamental abilities of the software with regards to the single data source principle, it provides a rich set of tools in the manufacturing environment in the form of tooling design and simulated CNC machining and output.
Tooling options cover specialty tools for molding, die-casting and progressive tooling design.
Release History.
The UNIX version was discontinued after 4.0, except x86-64 UNIX on Solaris. The name changed to Creo 1.0 after Pro/Engineer Wildfire 5.0 (rebranded PTC Creo Elements/Pro), took place on October 28, 2010, which coincided with PTC’s announcement of Creo, a new design software application suite.
For the first 10 years, PTC generally released 2 versions per year, with some exceptions. The initial release (Rev 1) was in 1988.
See also.
Comparable Software


Flow mark

Flow marks, also known as flow lines, are molding defects that can occur in the manufacturing process of injection molding. They are best described as "off tone" wavy lines/streaks or patterns in the molded part around the injection ports. They commonly occur when there is a large variation between cooling speeds of sections of the material as it flows through the mold.
Prevention Methods.
Flow mark causes vary for specific parts and production lines due to the variability in molds, machines, and materials. For the most part they are due to varying cooling speeds of the material as it flows through the mold. The different prevention methods for varying cooling speeds are as follows:
Injection Speed/Pressure.
Insufficient Injection speed and pressure can cause the injected material to cool and become stiffer during the injection process which can lead to a dull finish on the surface of the part. Increasing the speed will allow the material shot to fill the mold before it cools.
Material/Mold Temperature.
A low temperature will have a similar effect as a slow injection speed due to both causing the material to stiffen before the cycle completes. Increasing the temperature of the material or mold allows the material to flow without stiffening before the cycle completes.
If the temperature is increased too high, there is a chance to cause a different type of injection molding defect referred to as a burn mark.
Mold Design.
The design of a mold is one of the most important factors in correcting defects due to it controlling most of the process. For flow marks specifically, some causes that can be addressed are varying wall thicknesses, mold gate locations, and rough flow paths. Prevention for varying wall thicknesses is to round the corner where the thickness varies. This prevents the flow rate from suddenly decreasing or changing direction. Moving the location of mold gates away from mold coolant allows the material to flow more evenly and prevent premature cooling. Flow paths in the mold should allow the material to flow smoothly through the mold to prevent drastic variation in flow rate.


IMCO Carbide Tool

IMCO Carbide Tool is an American manufacturing company that researches, designs and manufactures high-performance cutting tools for a variety of applications in the aerospace, automotive, medical, petrochemical, and manufacturing industries. Founded in 1977 by Lawrence R. Osburn and headquartered in Perrysburg Twp, Ohio, IMCO serves a diverse customer base of small job shops to large production operations around the world.
History.
IMCO Carbide Tool is a family-owned and -operated company founded in 1977 by Lawrence R. Osburn. With his wife and two sons, Perry and Matthew, Osburn built his business in general-purpose end mills, burs, routers and drills for the automotive and manufacturing industries.
The sons served as company vice presidents, until Perry succeeded his father as President in 1984, with Matthew continuing as Vice President in charge of factory set-up, production processes, hiring, training, inventory management, supplier relations and quality oversight. As the machining industry was challenged by engineered materials with difficult-to-machine characteristics and more demanding specifications and tolerances, the brothers turned their focus on developing tools to meet those challenges.
IMCO began to research and develop end mills, working with customers to create tools capable of much higher performance with new and emerging high-speed machining technologies. Versatile tools dubbed Streaker M2 end mills were introduced in 1988. Streakers were designed especially for working in aluminum. A notoriously "soft" metal, aluminum tends to meld in the intense heat of the cutting zone before the chips can be evacuated. This causes the chips to congeal in the cutting zone, requiring downtime to clear the blockage and, often, replace the tool. Tests with customer shops showed that Streakers eliminate this clogging problem.
IMCO's M7 Omega-6 end mills, introduced in 2000, were designed to resolve problems in achieving high surface finishes, especially in hard-to-machine materials. Soon thereafter, IMCO launched another new product called enDURO M5 end mills, developed especially for working in and finishing aerospace alloys (titanium, stainless steels) and high-silicon aluminum. This line includes three- and five-flute designs to accommodate varying needs for chipload, chip evacuation and finish quality.
Products.
IMCO tools are designed, tested, sourced and manufactured in the U.S. for machining in a wide range of materials, such as aluminum, carbon and stainless steel, tool steels, titanium, cast iron, high-temperature alloys, copper and magnesium alloys, brass, bronze, composites, plastics, and graphite. IMCO tool categories include high-performance and general-purpose end mills, burs, drills, countersinks, rougher/finishers, reamers, routers, die trimmers and custom-made, special purpose precision tools for industrial applications. The company also performs custom modifications to off-the-shelf cutting tools.
IMCO Carbide Tool products begin with "blanks," or rods of micrograin carbide or ultra-fine micrograin carbide, because of its extreme hardness and favorable heat resistance.
IMCO specializes in high-performance end mills designed with variable fluting. Varying flute geometries break up the harmonics, or multiple mechanical frequencies that develop as tools spin and can cause tool instability and failure. Variable fluting breaks up harmonics and keeps the tool balanced as it turns for optimum tool stability. This, in turn, enables the tool to cut with greater precision.


Leaded copper

Leaded copper is a metal alloy of copper with lead. A small amount of lead makes the copper easier to machine. Alloys with a larger amount of lead are used for bearings. Brass and bronze alloys of copper may have lead added and are then also sometimes referred to as leaded copper alloys. Leaded copper and its alloys have been used since ancient times.
Applications.
Leaded copper alloys are used to make electrical connectors and mechanical bearings, especially in the automotive industry where high performance and reliability are required. Mechanical bearings can have high lead content. Such high lead content alloys are unsuitable for welding or brazing.
Machined alloys.
Alloys with around 2-4% lead are used for machined copper applications, where the lead content lubricates the copper and makes it easier to machine. These include high-quality electrical connectors where a high current capacity and low electrical resistance are required. Such connectors are used in industrial automation and the automotive industry. Brasses (copper alloyed with zinc) may also be leaded for the same reason.
Cast and sintered alloys.
High-strength casting copper alloys typically contain less than 2% lead. Bearing alloys are often cast or sintered onto a steel backing. Softer alloys with a higher lead content are also used, for example in bushes where conformance to the opposite bearing surface is important.
Some casting alloys have over 20% lead content but, due to their toxicity, they are no longer used.
Toxicity.
When lead alloys wear, lead is released into the environment. Lead is a heavy metal toxin and in recent times the use of leaded copper alloys has been reduced.
History.
Signs of leaded copper use are found in the manufacture of ancient Egyptian faience. By 1500 BC leaded copper could be found across the Old World from East Asia to Africa and Europe.
Enigmatic entries in a Chinese manuscript, the "Kao Gong Ji" dating from around 300 BC, were deciphered by scholars in 2022, and seem to indicate that a pre-prepared copper-lead alloy named "Xi" may have been used in the preparation of ancient bronzes. Another copper-tin-lead alloy named "Jin" was also tentatively identified as a pre-prepared component of Chinese bronzes. This part of the manuscript relates to an attempt to standardise the quality of bronze manufacture.


FR-2

FR-2 (Flame Resistant 2) is a NEMA designation for synthetic resin bonded paper, a composite material made of paper impregnated with a plasticized phenol formaldehyde resin, used in the manufacture of printed circuit boards. Its main properties are similar to NEMA grade XXXP (MIL-P-3115) material, and can be substituted for the latter in many applications.
Applications.
FR-2 sheet with copper foil lamination on one or both sides is widely used to build low-end consumer electronic equipment. While its electrical and mechanical properties are inferior to those of epoxy-bonded fiberglass, FR-4, it is significantly cheaper. It is not suitable for devices installed in vehicles, as continuous vibration can make cracks propagate, causing hairline fractures in copper circuit traces. Without copper foil lamination, FR-2 is sometimes used for simple structural shapes and electrical insulation.
Fabrication.
FR-2 can be machined by drilling, sawing, milling and hot punching. Cold punching and shearing are not recommended, as they leave a ragged edge and tend to cause cracking. Tools made of high-speed steel can be used, although tungsten carbide tooling is preferred for high volume production.
Adequate ventilation or respiration protection are mandatory during high-speed machining, as it gives off toxic vapors.


Welding helmet

A welding helmet is a type of personal protective equipment used in performing certain types of welding to protect the eyes, face, and neck from flash burn, sparks, infrared and ultraviolet light, and intense heat. The modern welding helmet used today was first introduced in 1937 by Willson Products.
Welding helmets are most commonly used in arc welding processes such as shielded metal arc welding, gas tungsten arc welding, and gas metal arc welding. They are necessary to prevent arc eye, a painful condition where the cornea is inflamed. Welding helmets can also prevent retina burns, which can lead to a loss of vision. Both conditions are caused by unprotected exposure to the highly concentrated infrared and ultraviolet rays emitted by the welding arc. Ultraviolet emissions from the welding arc can also damage uncovered skin, causing a sunburn-like condition in a relatively short period of welding. In addition to the radiation, gases or splashes can also be a hazard to the skin and the eyes.
Most welding helmets include a window covered with a filter called a lens shade, through which the welder can see to work. The window may be made of tinted glass, tinted plastic, or a variable-density filter made from a pair of polarized lenses. Different lens shades are needed for different welding processes. For example, metal inert gas (MIG) and tungsten inert gas (TIG) welding are low-intensity processes, so a lighter lens shade will be preferred.
The shade of lens that is suitable depends on the current rating of the weld. In the United States, OSHA recommends DIN shade numbers as shown in the following table:
Safety.
All welding helmets are susceptible to damages such as cracks that can compromise the protection from ultraviolet and infrared rays. In addition to protecting the eyes, the helmet protects the face from hot metal sparks generated by the arc and from UV damage. When overhead welding, a leather skull cap and shoulder cover are used to prevent head and shoulder burns.
Auto-darkening filters.
In 1981, Swedish manufacturer Hornell International introduced an LCD electronic shutter that darkens automatically when sensors detect the bright welding arc, the Speedglas Auto-Darkening Filter.
With such electronic auto-darkening helmets, the welder no longer has to get ready to weld and then nod their head to lower the helmet over their face. The advantage is that the welder does not need to adjust the position of welding helmet manually which not only saves time but also reduces the risk of exposure to the harmful light generated by the welding process.
In January 2004, 3M acquired all assets of Hornell, including the Adflo and Speedglas auto darkening helmets brand name and patents. Speedglas helmets are now sold by 3M.
ANSI standards.
In the United States, the industry standard for welding helmets is ANSI Z87.1+ which specifies performance of a wide variety of eye protection devices. The standard requires that auto-darkening helmets provide full protection against both UV and IR even when they are not in the darkened state. The standard is voluntary, so buyers should confirm that the helmet is ANSI Z87.1 compliant (indicated by appropriate labeling).


Microoptoelectromechanical systems

Microoptoelectromechanical systems (MOEMS), also known as optical MEMS, are integrations of mechanical, optical, and electrical systems that involve sensing or manipulating optical signals at a very small size. MOEMS includes a wide variety of devices, for example optical switch, optical cross-connect, tunable VCSEL, microbolometers. These devices are usually fabricated using micro-optics and standard micromachining technologies using materials like silicon, silicon dioxide, silicon nitride and gallium arsenide.
Merging technologies.
MOEMS includes two major technologies, microelectromechanical systems and micro-optics. Both these two technologies independently involve in batch processing similar to integrated circuits, and micromachining similar to fabrication of microsensor.
Parallel with MEMS developments and even earlier, sensor technology advanced to microsensors and joining with microactuators. Development of microsensors and microactuators were also due to a mother technology of micromachining. Micromachining is the root of everything we have today in high technology. This technology was never credited in history as it deserved. It was commercially used during the 1960s in Switzerland, for micromachining quartz orders of magnitudes harder than micromachining silicon. MEMS acronym was so powerful during the 1980s, that with no choice microsensors and microactuators that included micromachining, all joined MEMS.
History of MOEMS.
During 1991-1993, Dr. M. Edward Motamedi, a former Rockwell International innovator in the areas of both microelectromechanical systems and micro-optics, used internally the acronym of MOEMS for microoptoelectromechanical systems. This was to distinguish between optical MEMS and MOEMS, where optical MEMS could include bulk optics but MOEMS is truly based on microtechnology where MOEMS devices are batch-processed exactly like integrated circuits, but this is not true in most cases for optical MEMS.
In 1993, Dr. Motamedi officially introduced MOEMS for the first time, as the powerful combination of MEMS and micro-optics, in an invited talk at the SPIE Critical Reviews of Optical Science and Technology conference in San Diego. In this talk Dr. Motamedi introduced the figure below, for showing that MOEMS is the interaction of three major microtechnologies; namely micro-optics, micromechanics, and microelectronics.


Boring bar

A boring bar is a tool used in metalworking and woodworking. Boring is a technique used in many aspects of building. Woodworkers have used boring as a form of drilling for centuries. In woodworking, the boring tool is static in size and used to form circular plunge cuts. In metalworking, boring is slightly different in that the hole that results need not be circular. In metal boring the tool can be plunged and dragged on the X or Y axes to create a slot or asymmetrical hole or channel, or it may be moved only in an up-and-down motion (on the Z axis) to create a perfect circular hole.
Components.
Modern boring tools have three primary components although many differing designs. The parts include the body, bar holder and dial screw (graduated micro screw). The body, made of solid stock, has two basic parts. The top part threads or presses into the supporting shank. The lower part ("bar holder") is connected via dovetail, T-slots or a smooth notch with an adjustment for bore diameter via the "dial screw". As the dial screw is adjusted, the cutting bit/s are moved further out, creating a larger cut. This also can create some slight distortion if the cutting tool is moved further than the boring head is designed to support, if there is undue wear in the bearings supporting the tool or if the tool speed is too great for the off-balance effect caused by moving the tool too far from center. This is called "unbalanced gyroscope precession". Once the dial screw has been adjusted to give the proper cut a set screw is generally used to prevent any additional movement of the cutting head. The third basic part is the "boring tool". Boring tools can be mounted vertically or horizontally in many boring head designs.
Boring machines.
Boring can be done on mills, lathes or drill press machines, either with a boring head or with just a boring tool. The shorter the distance between the tool holder and the material, the less distortion created from vibration or unbalanced gyroscopic effects. The greater the distance (static or dynamic mounts) the more flex in the tool or an increase in the imbalance of a moving tool. Use of a boring head increases the mass of the tool holder and decreases the distance. If a vibration is created it will be at a higher frequency and the deflection of the tool from the desired path will be much smaller and easier to erase through repetitive tool passes. In the case of a dynamic tool (mill or press), the balance of the tool can be adjusted with counterweights if the tool is mounted perpendicular to the shaft or the tool length can be decreased.


Della Ferrera

Della Ferrera was an Italian motorcycle manufacturer active from 1909 to 1948. Four-valve motorcycles built by the company won events in the Trofeo Turistico Nazionale, at Cremona, and elsewhere. The company built a prototype for a cyclecar in 1924. The only model was a Cyclecar and was only produced in 1924. A four-cylinder two-stroke engine with a displacement of 707 cm³ provided the drive. The vehicle featured a four-speed gearbox and four-wheel brakes. The design-related top speed was given as 80 km/h. The Officine Meccanica Giuseppe Meldi took over the model in 1927 as the basis for its own vehicles.
From 1909, Della Ferrera was building a very sturdy Motorcycle that they were able to provide 100.000 KM warranty. Until the 1st world-war, Della Ferrera was one of the primary Motorcycle makers in Italy. The Motorcycles were made by hand, which was more common at the time. Therefore, the number of motorcycles built was low. Most of the parts were made by the brothers Della Ferrera, except for the tires and parts of the ignition, including the carburetors.


Workcell

A workcell is an arrangement of resources in a manufacturing environment to improve the quality, speed and cost of the process. Workcells are designed to improve these by improving process flow and eliminating waste. They are based on the principles of Lean Manufacturing as described in "The Machine That Changed the World" by Womack, Jones and Roos.
History.
Classical manufacturing management approaches dictate that costs be lowered by breaking the process into steps, and ensuring that each of these steps minimizes cost and maximizes efficiency. This discrete approach has resulted in machines placed apart from each other to maximize the efficiency and throughput of each machine. The traditional accounting for machine capitalization is based on the number of parts produced, and this approach reinforces the idea of lowering the cost of each machine (by having them produce as many parts as possible.) Increasing the number of parts (WIP) adds waste in areas such as Inventory and Transportation.
Large amounts of excess Inventory often now accumulate between the machines in the process for reasons to do with 'unbalanced' line capacities and batch processing. In addition, the parts must now be transported between the machines. An increase in the number of machines involved also will reduce each worker's multi-skilling proficiency (since that would need them to learn how to operate multiple machines, and they too will need to move between those machines.)
Lean Manufacturing focuses on optimizing the end-to-end process as a whole. This enables a focus in the process on creating a finished product at the lowest cost (instead of lowering the cost of each step.) A common approach to achieving this is known as the workcell. Machines involved in building a product are placed next to each other to minimize transportation of both parts and people (an L-shaped desk with upper shelves is a good office example, which enables many types of office equipment to be within the reach of a worker). This will minimize waste in both transportation and in the storage of excess inventory.
At first glance, lean workcells may appear to be similar to traditional workcells, but they are inherently different. For instance, lean workcells must be designed for minimal wasted motion, which refers to any unnecessary time and effort required to assemble a product. Excessive twists or turns, uncomfortable reaches or pickups, and unnecessary walking all contribute to wasted motion and may put error inducing stress upon the operator. Workcells can often be reconfigured easily to allow the adaptation of the process to fit takt time. This flexibility allows the work content to be adapted as demand or product mix changes.
Another Lean approach is to aim to have flexible manufacturing through small production lot sizes since this smooths production. Small lot sizes usually increases transportation waste, but this can be eliminated if machines are back-to-back in a workcell.
Implementation.
The implementation of workcells can reduce costs by an order of magnitude (90%).
In software development, the core of the workcell is the cross-functional team. This team differs from a more traditional waterfall team:


Selective laser melting

Selective laser melting (SLM) is one of many proprietary names for a metal additive manufacturing (AM) technology that uses a bed of powder with a source of heat to create metal parts. Also known as direct metal laser sintering (DMLS), the ASTM standard term is powder bed fusion (PBF). PBF is a rapid prototyping, 3D printing, or additive manufacturing technique designed to use a high power-density laser to melt and fuse metallic powders together.
History.
Selective which means the part is fully dense. This process is in all points very similar to other SLM processes, and is often considered as an SLM process. Among the companies that manufacture machines with SLM technology we find SLM solutions, owner of the SLM brand, EOS, Renishaw, DMG Mori, Concept laser, TRUMPF, Sisma, 3D Systems, 3D4MEC.
A similar process is electron beam melting (EBM), which uses an electron beam as the energy source.
Process.
Selective laser melting is able to process a variety of alloys, allowing prototypes to be functional hardware made out of the same material as production components. Since the components are built layer by layer, it is possible to design complex freeform geometries, internal features and challenging internal passages that could not be produced using conventional manufacturing techniques such as casting or otherwise machined. SLM produces fully dense durable metal parts that work well as both functional prototypes or end-use production parts.
The process starts by slicing the 3D CAD file data into layers, usually from 20 to 100 micrometers thick, creating a 2D cross-section of each layer; this file format is the industry standard .stl file used on most layer-based 3D printing or stereolithography technologies. This file is then loaded into a file preparation software package that assigns parameters, values and physical supports that allow the file to be interpreted and built by different types of additive manufacturing machines.
With selective laser melting, thin layers of atomized metal powder are evenly distributed using a re-coating mechanism onto a substrate plate, usually metal, that is fastened to an indexing platform that moves in the vertical (Z) axis. This takes place inside a chamber containing a tightly controlled atmosphere of inert gas, either argon or nitrogen at oxygen levels below 1000 parts per million. Once each layer has been distributed, each 2D slice of the part geometry is fused by selectively melting the powder. This is accomplished with a high-power laser beam, usually an ytterbium fiber laser with hundreds of watts. The laser beam is directed in the X and Y directions with two high frequency scanning mirrors and remains in focus along the layer utilising an F-Theta lens arrangement. The laser energy is intense and focused enough to permit full melting (fusion) of the particles to fore a solid structure. The process is repeated layer after layer until the part is complete.
SLM machines predominantly uses a high-powered Yb-fiber optic laser with standard laser powers ranging from 100 - 1000W. Inside the build chamber area, there is a material dispensing platform and a build platform along with a recoater system (blade or roller) used to evenly spread new powder across the build platform. . Parts are built up additively layer by layer, typically using layers 30-60 micrometers thick.
Materials.
Selective laser melting (SLM) machines can operate with a work space up to 1 m (39.37 in) in X, Y and Z. Some of the materials being used in this process can include Ni based super alloys, copper, aluminum, stainless steel, tool steel, cobalt chrome, titanium and tungsten. SLM is especially useful for producing tungsten parts because of the high melting point and high ductile-brittle transition temperature of this metal. In order for the material to be used in the process it must exist in atomized form (powder form). These powders are generally gas atomized prealloys, being the most economical process to obtain spherical powders on an industrial scale. Sphericity is desired because it guarantees a high flowability and packing density, which translates into fast and reproducible spreading of the powder layers. To further optimize flowability, narrow grain size distributions with a low percentage of fine particles like 15 - 45 µm or 20 - 63 µm are typically employed. Currently available alloys used in the process include AISI 316L, AISI 304, C67, F53, H13, 17-4 PH and 15-5 stainless steel, maraging steel, cobalt chromium, inconel 625 and 718, copper-based alloys (CW510 Brass, Ecobrass, Bronze), aluminum AlSi10Mg, and titanium Ti6Al4V.
The mechanical properties of samples produced using selective laser melting sintering differ from those manufactured using casting. AlSiMg samples produced using direct metal laser sintering exhibit a higher yieldengineering than those constructed of commercial as-cast A360.0 alloy by 43% when constructed along the xy-plane and 36% along the z-plane. While the yield strength of AlSiMg has been shown to increase in both the xy-plane and z-plane, the elongation at break decreases along the build direction. These improvement of the mechanical properties of the direct metal laser sintering samples has been attributed to a very fine microstructure.
Additionally, industry pressure has added more superalloy powders to the available processing including AM108.  It is not only the Print operation and orientation that provides a change in material properties, it is also the required post processing via Hot Isostatic Pressure (HIP) Heat Treat and shot peen that change mechanical properties to a level of noticeable difference in comparison to equiaxed cast or wrought materials.  Based on research done at the Tokyo Metropolitan University, it is shown that creep rupture and ductility are typically lower for additive printed Ni based superalloys compared to wrought or cast material. The directionality of print is a major influencing factor along with grain size. Additionally, wear properties are typically better as seen with the studies done on additive Inconel 718 due to surface condition; the study also demonstrated the laser power's influence on density and microstructure. Material Density that is generated during the laser processing parameters can further influence crack behavior such that crack reopening post HIP process is reduced when density is increased. It is critical to have a full overview of the material along with its processing from print to required post-print to be able to finalize the mechanical properties for design use.
Overview and benefits.
SLM is a fast developing process that is being implemented in both research and industry. This advancement is very important to both material science and the industry because it can not only create custom properties but it can reduce material usage and give more degrees of freedom with designs that manufacturing techniques can't achieve. Selective laser melting is very useful as a full-time materials and process engineer. Requests such as requiring a quick turnaround in manufacturing material or having specific applications that need complex geometries are common issues that occur in industry. Having SLM would really improve the process of not only getting parts created and sold, but making sure the properties align with whatever is needed out in the field. Current challenges that occur with SLM are having a limit in processable materials, having undeveloped process settings and metallurgical defects such as cracking and porosity. The future challenges are being unable to create fully dense parts due to the processing of aluminum alloys. Aluminum powders are lightweight, have high reflectivity, high thermal conductivity, and low laser absorptivity in the range of wavelengths of the fiber lasers which are used in SLM.
These challenges can be improved with doing more research in how the materials interact when being fused together.
Defect formation.
Despite the large successes that SLM has provided to additive manufacturing, the process of melting a powdered medium with a concentrated laser yields various microstructural defects through numerous mechanisms that can detrimentally affect the overall functionality and strength of the manufactured part. Although there are many defects that have been researched, we will review some of the major defects that may arise from SLM in this section.
Two of the most common mechanical defects include lack of fusion (LOF) or cracking within solidified regions. LOF involves the entrapment of gas within the structure rather than a cohesive solid. These defects can arise from not using a laser source with adequate power or scanning across the powdered surface too quickly, thereby melting the metal insufficiently and preventing a strong bonding environment for solidification. Cracking is another mechanical defect in which low thermal conductivity and high thermal expansion coefficients generate sufficiently high amounts of internal stresses to break bonds within the material, especially along grain boundaries where dislocations are present.
Additionally, although SLM solidifies a structure from molten metal, the thermal fluid dynamics of the system often produces inhomogeneous compositions or unintended porosity which can cumulatively affect the overall strength and fatigue life of a printed structure. For example, the directed laser beam can induce convection currents upon direct impact in a narrow "keyhole" zone or throughout the semi-molten metal that can impact the material’s overall composition. Similarly, it is found that during solidification, dendritic microstructures progress along temperature gradients at different speeds, thus producing different segregation profiles within the material. Ultimately, these thermal fluid dynamical phenomena generate unwanted inconsistencies within the printed material, and further research into mitigating these effects will continue to be necessary.
Pore formation is a very important defect when samples are printed using SLM. Pores are revealed to form during changes in laser scan velocity due to the rapid formation then collapse of deep keyhole depressions in the surface which traps inert shielding gas in the solidifying metal.
Lastly, secondary effects that arise from the laser beam can unintentionally affect the structure’s properties. One such example is the development of secondary phase precipitates within the bulk structure due to the repetitive heating within solidified lower layers as the laser beam scans across the powder bed. Depending on the composition of the precipitates, this effect can remove important elements from the bulk material or even embrittle the printed structure. Not only that, in powder beds containing oxides, the power of the laser and produced convection currents can vaporize and "splatter" oxides at other locations. These oxides accumulate and have a non-wetting behavior, thereby producing a slag that not only removes the beneficial nature of oxide within the composition but also provides a mechanistically favorable microenvironment for material cracking.
Mechanical properties.
High temperature gradients are presented during selective laser melting (SLM) processes, which causes non-equilibrium conditions at the solid/liquid interface, thereby leading to rapid solidification as the melt pool undergoes a phase transformation from liquid to solid. As a consequence, a wide range of effects might take place like the formation of non-equilibrium phases and changes in the microstructure.
For the reasons above, the mechanical properties of alloys produced by SLM can deviate substantially from those conventionally manufactured counterparts in their as-built state. A central characteristic of SLM-manufactured alloys is large anisotropy in mechanical properties . While the grain structure in cast metals is typically characterized by roughly uniform, isotropic grains, alloys manufactured using SLM exhibit substantial elongation of grains in the build direction. The anisotropy in grain structure is associated with anisotropy in the distribution of defects, the direction of crack propagation, and ultimately the mechanical properties.
On the other hand, because of the special thermo-kinetic features associated with SLM, there are many novel microstructural architectures unique to this process . As a new processing technique, SLM can produce a unique microstructure that is difficult to achieve using conventional techniques.
Nickel-based superalloys.
Enhancements in creep resistance, ultimate tensile strength and toughness have been reported in nickel alloys. Inconel IN625, a precipitation-hardened nickel-chromium alloy, showed equal or even higher creep strength at elevated temperatures of 650 ̊C and 800 ̊C than wrought IN625. However, SLM-manufactured IN625 exhibited inferior ductility under creep testing conditions. By deploying cyclic heat treatments, both SLM and wrought IN625 obtained some additional strength. The amount of extra strength in the alloys was generally proportional to the matrix volume fraction of γ’’ phase (at 650 ̊C) and δ phase (at 800 ̊C).
The fatigue strength and hardness of SLM-manufactured alloys when handling cyclic loads at high temperature, however, tends to be significantly inferior to that of cast or wrought alloys. For another superalloy Inconel IN718, researchers found the additively manufactured material showed large columnar grains with an orientation parallel to the building direction, whereas the wrought material showed a fine-grained structure with no significant texture.
SLM-based additive manufacturing of nickel superalloys still poses significant challenges due to these alloys’ complex composition. With multiple alloying elements and high aluminum/titanium fraction, these materials, when consolidated through SLM form various secondary phases, which affects the processability and leading to weakness within the structure.
Iron-based alloys (Stainless steels).
Stainless steel grade 316L is an austenitic iron-based alloy that features a low carbon content (ultimate tensile strength (UTS) is also lower for AM specimens since strain hardening is insignificant.
The fracture in the SLM-manufactured material is mainly between the grains. The grain boundary damage leads to cracking and subsequently to the failure of the material. The deformation is caused and accelerated by the appearance of precipitates at the grain boundaries. The higher stacking fault energy (SFE) of SLM 316L steel presumably also contributed to its creep behavior.
Applications.
The types of applications most suited to the selective laser melting process are complex geometries and structures with thin walls and hidden voids or channels on the one hand or low lot sizes on the other hand. Advantage can be gained when producing hybrid forms where solid and partially formed or lattice type geometries can be produced together to create a single object, such as a hip stem or acetabular cup or other orthopedic implant where osseointegration is enhanced by the surface geometry. Much of the pioneering work with selective laser melting technologies is on lightweight parts for aerospace where traditional manufacturing constraints, such as tooling and physical access to surfaces for machining, restrict the design of components. SLM allows parts to be built additively to form near net shape components rather than by removing waste material.
Traditional high-volume manufacturing techniques have a relatively high set-up cost (e.g. Injection moulding, Forging, Investment casting). While SLM currently has a high cost per part owing to its time sensitivity and the overall capital costs of the equipment. However, for limited quantise of bespoke customisable parts, the process remains attractive for a number or uses. This is the case e.g. for spares/replacement parts for obsolete equipment and machines (e.g. vintage cars) or customisable products like implants designed for individual patients .
Tests by NASA's Marshall Space Flight Center, which is experimenting with the technique to make some difficult-to-fabricate parts from nickel alloys for the J-2X and RS-25 rocket engines, show that difficult to make parts made with the technique are somewhat weaker than forged and milled parts but often avoid the need for welds which are weak points.
This technology is used to manufacture direct parts for a variety of industries including aerospace, dental, medical and other industries that have small to medium size, highly complex parts and the tooling industry to make direct tooling inserts or those requiring short lead times. The technology is used both for rapid prototyping, as it decreases development time for new products, and production manufacturing as a cost saving method to simplify assemblies and complex geometries.
The Northwestern Polytechnical University of China is using a similar system to build structural titanium parts for aircraft. An EADS study shows that use of the process would reduce materials and waste in aerospace applications.
On September 5, 2013 Elon Musk tweeted an image of SpaceX's regeneratively-cooled SuperDraco rocket engine chamber emerging from an EOS 3D metal printer, noting that it was composed of the Inconel superalloy. In a surprise move, SpaceX announced in May 2014 that the flight-qualified version of the SuperDraco engine is fully printed, and is the first fully printed rocket engine. Using Inconel, an alloy of nickel and iron, additively-manufactured by direct metal laser sintering, the engine operates at a chamber pressure of at a very high temperature. The engines are contained in a printed protective nacelle, also DMLS-printed, to prevent fault propagation in the event of an engine failure. The engine completed a full qualification test in May 2014, and is slated to make its first orbital spaceflight in April 2018.
The ability to 3D print the complex parts was key to achieving the low-mass objective of the engine. According to Elon Musk, "It’s a very complex engine, and it was very difficult to form all the cooling channels, the injector head, and the throttling mechanism. Being able to print very high strength advanced alloys ... was crucial to being able to create the SuperDraco engine as it is."
The 3D printing process for the SuperDraco engine dramatically reduces lead-time compared to the traditional cast parts, and "has superior strength, ductility, and fracture resistance, with a lower variability in materials properties."
Also in 2018, the FDA approved the first-ever 3D printed spine implant made from titanium using SLM.
Other applications.
Laser melting can produce chemical structures (pure metals, their oxides and carbides), and physical structures (homogeneous, alloys, composites, gold-iron, gold-cobalt, gold-nickel alloys).
Potential.
Selective laser melting or additive manufacturing, sometimes referred to as rapid manufacturing or rapid prototyping, is in its infancy with relatively few users in comparison to conventional methods such as machining, casting or forging metals, although those that are using the technology have become highly proficient. Like any process or method selective laser melting must be suited to the task at hand. Markets such as aerospace or medical orthopedics have been evaluating the technology as a manufacturing process. Barriers to acceptance are high and compliance issues result in long periods of certification and qualification. This is demonstrated by the lack of fully formed international standards by which to measure the performance of competing systems. The standard in question is ASTM F2792-10 Standard Terminology for Additive Manufacturing Technologies.
Difference from selective laser sintering (SLS).
The use of SLS refers to the process as applied to a variety of materials such as plastics, glass, and ceramics, as well as metals. What sets SLM apart from other 3D printing process is the ability to fully melt the powder, rather than heating it up to a specific point where the powder grains can fuse together, allowing the porosity of the material to be controlled. On the other hand, SLM can go one step further than SLS, by using the laser to fully melt the metal, meaning the powder is not being fused together but actually liquified long enough to melt the powder grains into a homogeneous part. Therefore, SLM can produce stronger parts because of reduced porosity and greater control over crystal structure, which helps prevent part failure. Additionally, certain types of nanoparticles with minimized lattice misfit, similar atomic packing along matched crystallographic planes and thermodynamic stability can be introduced into metal powder to serve as grain refinement nucleates to achieve crack-free, equiaxed, fine-grained microstructures. However, SLM is only feasible when using a single metal powder.
Benefits.
SLM has many benefits over traditional manufacturing techniques. The ability to quickly produce a unique part is the most obvious because no special tooling is required and parts can be built in a matter of hours.
SLM is also one of the few additive manufacturing technologies being used in production. Since the components are built layer by layer, it is possible to design internal features and passages that could not be cast or otherwise machined. Complex geometries and assemblies with multiple components can be simplified to lighter and fewer parts with a more cost-effective assembly. DMLS does not require special tooling like castings, so it is convenient for short production runs.
Environmental impact.
There are various components, environments, and material considerations that can affect the environmental impact that the SLM process has. First, the embodied energy that was used to make the printer, which has more than 500 parts, contributes around 124,000 MJ for a standard Renishaw AM250. It is important to note that the most prominent material is steel, which is 100% recyclable. To truly take advantage of the recyclability, a cradle-to-cradle approach can be implemented to ensure that all steel parts are properly discarded of at their end-life through disassembly. The electric use is often the most energy intensive part of the printer, as the high power lasers, chillers, configurations, and part separation all contribute to this. Less volume of parts, more active time, more active idle time (coolers running), and electrical discharge machining (EDM) all increase the energy usage. The higher end of on-site energy during use can be around 640 MJ per part while more efficient use is around 40 MJ per part. In this, a main factor that can be optimized for environmental friendliness is the use of fully renewable energy rather than electric made through gas or coal. Considering now embodied energy of the total lifecycle, at the energy intensive end is less efficient printing processes totaling 2400+ MJ per part while more efficient processes can be as low as 140 MJ per part. Ultimately, the total embodied energy considering all parts made is dependent on many factors but is almost always dominant during the printing phase and more specifically during long idle times and post-processing part removal through EDM. The exception to this is in research environments where the machine is not constantly used and use is more infrequent, in this case, the embodied energy from primary processing and manufacturing is dominant.
Transportation costs will vary on manufacturing plants and consumers but these values are often negligible (<1%) in comparison to other high impacting parts of the SLM lifecycle. Other factors that are negligible, yet sometimes varied, are: inert gas use, material (powder) waste, materials used, atomization, and disposal of machine components.
Depending on the part made and its intended use, SLM can help make more lightweight parts with complex dimensions which reduce both energy intensive post-processing machining such as EDM or a computer numerical control (CNC) machining and decrease part weight. Often a direct comparison can only be made by looking at parts made through two different processes. An example is a turbine blade manufactured by investment casting and SLM, where 10853.34 kWh and 10181.57kWh were used to make the same part, respectively. Also conventional manufacturing contributed to 7,325 kgCO2 while AM had 7,027 kgCO2 of emissions. This means that in this specific scenario AM is beneficial by 4%, which could be significant over the 25,578 aircraft worldwide. Another example is the 1kg weight reduction through a hydraulic valve body which estimates a saving of 24,500L of jet fuel and 63 tons of CO2 emissions from a lightweight design and decreased material used compared to traditional manufacturing methods. SLM is often a more sustainable option due to decreased raw material use, less complex tool use, lightweight part potential, near-perfect final geometries, and on-demand manufacturing.
Constraints.
The aspects of size, feature details and surface finish, as well as print through dimensional error in the Z axis may be factors that should be considered prior to the use of the technology. However, by planning the build in the machine where most features are built in the x and y axis as the material is laid down, the feature tolerances can be managed well. Surfaces usually have to be polished to achieve mirror or extremely smooth finishes.
For production tooling, material density of a finished part or insert should be addressed prior to use. For example, in injection molding inserts, any surface imperfections will cause imperfections in the plastic part, and the inserts will have to mate with the base of the mold with temperature and surfaces to prevent problems.
Independent of the material system used, the SLM process leaves a grainy surface finish due to "powder particle size, layer-wise building sequence and [the spreading of the metal powder prior to sintering by the powder distribution mechanism]."
Metallic support structure removal and post processing of the part generated may be a time-consuming process and require the use of machining, EDM and/or grinding machines having the same level of accuracy provided by the RP machine.
Laser polishing by means of shallow surface melting of SLM produced parts is able to reduce surface roughness by use of a fast-moving laser beam providing "just enough heat energy to cause melting of the surface peaks. The molten mass then flows into the surface valleys by surface tension, gravity and laser pressure, thus diminishing the roughness."
When using rapid prototyping machines, files, which do not include anything but raw mesh data in binary (generated from Solid Works, CATIA, or other major CAD programs) need further conversion to and files (the format required for non-stereolithography machines). Software converts file to files, as with the rest of the process, there can be costs associated with this step.
Machine components.
The typical components of a SLM machine include: laser source, roller, platform piston, removable build plate, supply powder, supply doses (e.g. piston), and optics and mirrors. The typical build envelope across most platforms are (e.g., for EOS M 290) of 250 x 250 x 325 mm, and the ability to 'grow' multiple parts at one time,


Liuyang High-Tech Industrial Development Zone  is a Hi-tech Industrial Development Zone at province level in Liuyang City, Hunan Province, China. It is the 2nd largest industrial zone of Liuyang by economic volume, after the Liuyang Economic and Technological Development Zone. The industrial zone is the original Liuyang Manufacturing industrial Base  created in 2003, it was Changed to the present name on 14 July 2016. The industrial zone centers in Yong'an Town of Liuyang, it covers an area of . As of 2015, its gross output value of industries is CNY 30.31 billion (US$4.87 billion), the financial revenue reaches 1.01 billion yuan (US$0.16 billion).


2017 Copa do Brasil Third Round

The 2017 Copa do Brasil Third Round was played from 8 March to 5 April 2017, to decide the 10 teams advancing to the Fourth Round. In this year, each tie was played on a home-and-away two-legged basis. If tied on aggregate, the away goals rule would be used. If still tied, extra time would not be played, and the penalty shoot-out would be used to determine the winner. Hosting was determined by a draw.
Matches.

Match 61.
"Sport won 4–0 on aggregate and advanced to the fourth round."
Match 62.
"Joinville won 3–2 on aggregate and advanced to the fourth round."
Match 63.
"Cruzeiro won 5–0 on aggregate and advanced to the fourth round."
Match 64.
"Fluminense won 4–3 on aggregate and advanced to the fourth round."
Match 65.
"Internacional won 7–1 on aggregate and advanced to the fourth round."
Match 66.
"Corinthians won 3–1 on aggregate and advanced to the fourth round."
Match 67.
"Goiás won 5–1 on aggregate and advanced to the fourth round."
Match 68.
"Vitória won 2–1 on aggregate and advanced to the fourth round."
Match 69.
"Tied 0–0 on aggregate, Paraná won on penalties and advanced to the fourth round."
Match 70.
"São Paulo won 4–2 on aggregate and advanced to the fourth round."


Kamalini Ramdas

Kamalini Ramdas is a Professor of Management Science and Operations and Deloitte Chair in Innovation & Entrepreneurship at London Business School, with expertise in the areas of innovation, entrepreneurship, and operations management. Ramdas' research examines innovative approaches, including service innovation, operational innovation, and business model innovation, to accelerate value creation in various service and manufacturing industries.
Career.
Kamalini Ramdas earned her BS in mathematics from St. Stephen's College, Delhi University in 1986, M.S. in operations research from University of Delaware in 1989, and PhD in operations management from the Wharton School of University of Pennsylvania in 1995. Prior to joining London Business School in 2008, Ramdas served as Associate Professor of Business Administration at University of Virginia Darden School of Business. She was also on the faculty of McCombs School of Business of The University of Texas at Austin.
At London Business School, Ramdas is a Professor of Management Science and Operations and Deloitte Chair in Innovation & Entrepreneurship. She also serves as the Subject Area Chair of Management Science & Operations.
Between 2019 and 2020, she served as President of the Manufacturing and Service Operations Management Society (MSOM), one of the largest societies of the Institute for Operations Research and the Management Sciences (INFORMS).
Academic work.
Ramdas is known for her work in innovation, entrepreneurship, and operations management. Her work has found applications in a wide range of industries, including healthcare, telecommunication, consumer packaged goods, and assembled products.
In particular, she is a pioneering scholar in innovation in healthcare delivery, known internationally for her work in shared medical appointments. In 2011, she was invited to present her work on innovation in healthcare delivery at the World Economic Forum in Davos.
She serves or has served on the editorial board of major operations management journals, including "Management Science", "Manufacturing & Service Operations Management", "IEEE Transactions on Engineering Management", and "Productions and Operations Management".
Publications.
According to Google Scholar, Ramdas' 10 most widely cited papers are:


Maskless lithography

Maskless lithography (MPL) is a photomask-less photolithography-like technology used to project or focal-spot write the image pattern onto a chemical resist-coated substrate (e.g. wafer) by means of UV radiation or electron beam.
In microlithography, typically UV radiation casts an image of a time constant mask onto a photosensitive emulsion (or photoresist).
Traditionally, mask aligners, steppers, scanners, and other kinds of non-optical techniques are used for high speed microfabrication of microstructures, but in case of MPL, some of these become redundant.
Maskless lithography has two approaches to project a pattern: rasterized and vectorized. In the first one it utilizes generation of a time-variant intermittent image on an electronically modifiable (virtual) mask that is projected with known means (also known as Laser Direct Imaging and other synonyms). In the vectored approach, direct writing is achieved by radiation that is focused to a narrow beam that is scanned in vector form across the resist. The beam is then used to directly write the image into the photoresist, one or more pixels at a time. Also combinations of the two approaches are known, and it is not limited to optical radiation, but also extends into the UV, includes electron-beams and also mechanical or thermal ablation via MEMS devices.
Advantages.
The MPL advantage is a high speed parallel manipulation of the pattern enabled by a large and cheap available computing capacity, which is not an issue with the standard approach that decouples to a slow, but precise structuring process for writing a mask from a fast and highly parallel copy process to achieve high replication throughputs as demanded by industry.
A key advantage of maskless lithography is the ability to change lithography patterns from one run to the next, without incurring the cost of generating a new photomask. This may prove useful for double patterning or compensation of non-linear material behavior (e.g. when utilizing cheaper, non-crystalline substrate or to compensate for random placement errors of preceding structures).
Disadvantages.
The main disadvantages are complexity and costs for the replication process, the limitation of rasterization in respect to oversampling causes aliasing artefact, especially with smaller structures (which may affect yield), while direct vector writing is limited in throughput. Also the digital throughput of such systems forms a bottleneck for high resolutions, i.e. structuring a 300mm diameter wafer with its area of ~707cm² requires about 10 TiB of data in a rasterized format without oversampling and thus suffers from step-artefacts (aliasing). Oversampling by a factor of 10 to reduce these artefacts adds another two orders of magnitude 1 PiB per single wafer that has to be transferred in ~1 min to the substrate to achieve high volume manufacturing speeds.
Industrial maskless lithography is therefore currently only widely found for structuring lower resolution substrates, like in PCB-panel production, where resolutions ~50µm are most common (at ~2000 times lower throughput demand on the components).
Forms.
Currently, the main forms of maskless lithography are electron beam and optical. In addition, focused ion beam (FIB) systems have established an important niche role in failure analysis and defect repair. Also, systems based on arrays of mechanical and thermally ablative probe tips have been demonstrated.
Electron beam (e-beam).
The most commonly used form of maskless lithography today is electron beam lithography. Its widespread use is due to the wide range of electron beam systems available accessing an equally wide range of electron beam energies (~10 eV to ~100 keV). This is already being used in wafer-level production at eASIC, which uses conventional direct-write electron beam lithography to customize a single via layer for low-cost production of ASICs.
Most maskless lithography systems currently being developed are based on the use of multiple electron beams. The goal is to use the parallel scanning of the beams to speed up the patterning of large areas. However, a fundamental consideration here is to what degree electrons from neighboring beams can disturb one another (from Coulomb repulsion). Since the electrons in parallel beams are traveling equally fast, they will persistently repel one another, while the electron lenses act over only a portion of the electrons' trajectories.
Optical.
Direct laser writing is a very popular form of optical maskless lithography, which offers flexibility, ease of use, and cost effectiveness in R&D processing (small batch production). The underlying technology uses spatial light modulating (SLM) micro-arrays based on glass to block laser pathway from reaching a substrate with a photoresist (in similar manner to digital micromirror devices). This equipment offers rapid patterning at sub-micrometer resolutions, and offers a compromise between performance and cost when working with feature sizes of approximately 200 nm or greater. Direct laser writing for microelectronics packaging, 3D electronics and heterogeneous integration were developed in 1995 at the Microelectronics and Computer Technology Corporation (or MCC) in Austin, Texas. The MCC system was fully integrated with precision control for 3D surfaces and artificial intelligence software with real-time machine learning and included laser wavelengths for standard i-line resist and DUV 248nm. The MCC system also included circuit editing capabilities for isolating circuits on a programmable wafer design. In 1999, the MCC system was advanced for use in MEMS manufacturing.
Interference lithography or holographic exposures are not maskless processes and therefore do not count as "maskless", although they have no 1:1 imaging system in between.
Plasmonic direct writing lithography uses localized surface plasmon excitations via scanning probes to directly expose the photoresist.
For improved image resolution, ultraviolet light, which has a shorter wavelength than visible light, is used to achieve resolution down to around 100 nm. The main optical maskless lithography systems in use today are the ones developed for generating photomasks for the semiconductor and LCD industries.
In 2013, a group at Swinburne University of Technology published their achievement of 9 nm feature size and 52 nm pitch, using a combination of two optical beams of different wavelengths.
DLP technology can also be used for maskless lithography.
Focused ion beam.
Focused ion beam systems are commonly used today for sputtering away defects or uncovering buried features. The use of ion sputtering must take into account the redeposition of sputtered material.
Probe-tip contact.
IBM Research has developed an alternative maskless lithography technique based on atomic force microscopy. In addition, Dip Pen Nanolithography is a promising new approach for patterning submicrometer features.
Research.
2000s.
Technologies that enable maskless lithography is already used for the production of photomasks and in limited wafer-level production. There are some obstacles ahead of its use in high-volume manufacturing. First, there is a wide diversity of maskless techniques. Even within the electron-beam category, there are several vendors (Multibeam, Mapper Lithography, Canon, Advantest, Nuflare, JEOL) with entirely different architectures and beam energies. Second, throughput targets exceeding 10 wafers per hour still need to be met. Third, the capacity and ability to handle the large data volume (Tb-scale) needs to be developed and demonstrated.
In recent years DARPA and NIST have reduced support for maskless lithography in the U.S.
There was a European program that would push the insertion of maskless lithography for IC manufacturing at the 32-nm "half-pitch" node in 2009. Project name was MAGIC, or "MAskless lithoGraphy for IC manufacturing", in frame of EC 7th Framework Programme (FP7).
Due to the increased mask costs for multiple patterning, maskless lithography is once again prompts relevant research in this field.
DARPA (United States).
Since at least 2001 DARPA has invested in a variety of maskless patterning technologies including parallel e-beam arrays, parallel scanning probe arrays, and an innovative e-beam lithography tool to enable low-volume manufacturing process. The technology is codenamed as Gratings of Regular Arrays and Trim Exposures (GRATE) (previously known as Cost Effective Low Volume Nanofabrication).
Economics.
Foundries.
In 2018 the Dutch and Russia jointly funded (Rusnano) company Mapper Lithography producing multi e-beam maskless lithography MEMS components went bankrupt and was acquired by ASML Holding, a major competitor at the time. The foundry producing devices is located near Moscow, Russia. As of early 2019 it was run by Mapper LLC. The Mapper Lithography originally was created at Delft University of Technology in 2000.


Bharathidasan University

Bharathidasan University (BDU) is a university in the city of Tiruchirappalli, Tamil Nadu, India. It is located on Tiruchirappalli-Pudukkottai National Highway 336. It has affiliated colleges in the districts of Ariyalur district, Karur, Nagapattinam, Perambalur, Pudukkottai, Thanjavur, Tiruvarur and Tiruchirapalli. It is a recognised university, supported by the University Grants Commission of India. All major faculties of science and arts are represented. The university has totally 4 Faculties, 16 Schools, 37 Departments and 29 Specialized Research Centres.
The University Departments/Schools are offering 151 programmes including 40 PG programmes in M.A., M.Sc. and M.Tech. The above programmes are conducted under the Choice Based Credit System (CBCS) in Semesters: 31 M.Phil., 33 Ph.D., 19 P.G. Diploma, 11 Diploma and 10 Certificates. In addition to the regular teaching programmes in the Departments and Schools, the university under its Distance Education mode is conducting 15 UG and 26 PG programmes. All the UG and PG programmes are conducted under non-semester system and MCA and MBA programmes are conducted under semester system along with the regular programmes. The MCA and MBA programmes conducted under this mode are very popular.
Faculties and schools.
The university has the following faculties and schools:
Affiliated colleges.
Autonomous arts and science colleges.
1. Government Arts College (Autonomous), Karur - 639 005.
2. Government College (Autonomous), Kumbakonam - 612 001.
3. H.H. The Rajah's College (Autonomous), Pudukkottai - 622 001.
4. Rajah Serfoji Government College, (Autonomous) Thanjavur - 613 005.
5. Thanthai Periyar Government Arts and Science College (Autonomous), Tiruchirappalli - 620 023.
6. Government College for Women (Autonomous), Kumbakonam - 612 001.
7. K. N. Government College for Women (Autonomous) Thanjavur - 613 007.
8. Kaalaignar Karunanidhi Government Arts College for Women, (Autonomous)
Pudukkottai - 622 001.
9. A.V.V.M. Sri Pushpam College (Autonomous), Poondi - 613 503.
10. Bishop Heber College, (Autonomous) Tiruchirappalli - 620 017
11. Jamal Mohamed College, (Autonomous) Tiruchirappalli - 620 020.
12. National College (Autonomous), Tiruchirappalli - 620 001
13. Nehru Memorial College, (Autonomous) Puthanampatti - 621 007.
14. St. Joseph's College (Autonomous), Tiruchirappalli - 620 002.
15. A.D.M. College for Women, (Autonomous) Nagapattinam - 611 001.
16. Holy Cross College (Autonomous), Tiruchirappalli - 620 002.
17. Seethalakshmi Ramaswami College, (Autonomous) Tiruchirappalli - 620 002.
18. Edayathangudi G.S. Pillai Arts & Science College, Nagapattinam - 611 001.
19. J.J. College of Arts & Science(Autonomous), Namanasamuthiram, Pudukkottai - 622 404
20. Srimad Andavan Arts & Science College, Thiruvanaikoil, Tiruchirappalli - 620 005.
21. Thanthai Hans Roever College, Perambalur - 621 212.
22. Cauvery College for Women (Autonomous), Annamalai Nagar, Tiruchirappalli - 620 018
23. Dhanalakshmi Srinivasan College of Arts & Science for Women, Perambalur - 621 212
24. Sengamala Thayaar Educational Trust Women's College, Mannargudi - 614 001
Non-autonomous arts and science colleges.
1. A.A. Government Arts College, Musiri - 621 201.
2. Dr. Kalaignar Government Arts College, Kulithalai (Sattamandra Ponvizha), Ayyar Malai, Kulithalai, Karur - 639 120
3. Dr. Puratchi Thalaivar M.G.R.Govt. Arts & Science College, (Boys Higher Secondary School) Kudavasal 612 601, Thiruvarur District
4. Government Arts & Science College(Co-Education), Veppanthattai, Perambalur.
5. Government Arts and Science College, Community Hall, Amman Nagar, Aravakurichi TK, Karur Dt - 639201.
6. Government Arts and Science College, Govt. Boys Higher Secondary School Campus, Thirumayam TK - Pudukottai Dt - 622507.
7. Government Arts and Science College, Old Block Development Office, Poothalur, Thanjavur Dt. - 613 102.
8. Government Arts and Science college, Govt. Polytechnic campus, Aranthangi - 614 616.
9. Government Arts and Science College, Jayankondam, Ariyalur Dt. - 621 802.
10. Government Arts and Science College, Kadambadi Main Road, Opp. ADJ Dharamambal Polytechnic, Nagappattinam - 611 001.
11. Government Arts and Science College, Karambakudi, Pudukkottai District
12. Government Arts and Science College, Lalgudi - 621 601
13. Government Arts and Science College, Perambalur -621 107.
14. Government Arts and Science College, Peravurani, Thanjavur District
15. Government Arts and Science College, Punchayat Union Model Primary School, Pannankombu, Manapparai TK, Tiruchirappalli 621306
16. Government Arts and Science College, Regional ITI Campus, Kalaignar Nagar, Alangudi TK - Pudukottai - 622301
17. Government Arts and Science College, Tharagampatti, Karur (Dt.)
18. Government Arts College, Ariyalur - 621 713.
19. Government Arts College, Tiruchirappalli - 620 022
20. Government College of Arts and Science, Govt. Boys Higher Secondary School Campus, South Street, Nannilam - Thiurvarur (Dt.) 610 105.
21. Government College of Arts and Science, Opp. To Kasturibai Gandhi Kanniya Gurukulam, Nagai Road, Vedaranyam - 614 810.
22. Government College of Arts and Science, Govt. Higher Secondary School Campus, Inamkulathur - 621 203
23. Government College of Arts and Science, Thandalaichery, Velur Post,
Thiruthuraipoondi- 614 715, Thiruvarur (Dt.)
24. M.R. Government Arts College, Mannargudi - 614 001.
25. Thiru. Vi. Ka. Government Arts College, Thiruvarur - 610 003.
26. Government Arts and Science College (Women), Orathanad - 614 625
27. Government Arts and Science College for Women, Jamiya Elementary School Campus, Jinnah Street, Koothanallur, Tiruvarur Dt. - 614101
28. Government Arts and Science College for Women, Veppur, Perambalur District
29. Ganesar Senthamil College of Arts and Science, Melaisivapuri - 622 403.
30. Khadir Mohideen College, Adirampattinam - 614 701
31. Rajah's College, Thiruvaiyaru - 613 204.
32. S.K.S.S. Arts College, Thiruppanandal - 612 504.
33. Tamilavel Umamaheswaranar Karanthai Arts College, Thanjavur - 613 002.
34. Urumu Dhanalakshmi College, Tiruchirappalli - 620 019.
35. Aadhavan Arts and Science College, Alathur Village Chettiyappatti Panchayat, Manapparai T.K., Tiruchirappalli-621 306
36. ABI & ABI College, Vayalur, Thanjavur - 613 003.
37. Adaikala Matha College, Arun Nagar, Vallam, Thanjavur - 613 403.
38. Annai College of Arts & Science, Kumbakonam-612 503.
39. Annai Vailankanni Arts & Science College, V.O.C. Nagar Thanjavur 613 007
40. Arputha College of Arts & Science, Arputha Nagar, Vamban - 622 303
41. Arungarai Amman College of Arts & Science, Karur District - 639 202
42. Bharath College of Science & Management, South Garden, Thanjavur - 613 007.
43. Cambridge College of Arts and Science, Vettamangalam, Karur District - 639 117
44. Care College of Arts & Science, No.27, Thayanur Village, Trichy 620 009
45. Christhu Raj College, Panjapur, Edamalaipatti Pudur, Tiruchirappalli - 620 012
46. CSI - Bishop Solomon Doraisawmy College of Arts and Science, Karur - 639001
47. Dharmambal Ramasamy Arts & Science College, Orathanadu T.k.Thanjavur - 614 625.
48. Dr. Nallikuppusamy Arts College, Manakkarambai, Thanjavur - 613 003.
49. Elizabeth College of Arts and Science, Annamangalam(P.O), Vepanthattai T.K, Perambalur - 620 102
50. Enathi Rajappa College of Arts & Science, Enathi Post, Pattukkottai - 614 615
51. Imayam College of Arts & Science, Thuraiyur- 621 206
52. Indra Ganesan College of Arts & Science, Madurai Main Road, Manikandam Post, Tiruchirappalli 620 012
53. Jairams Arts and Science College NH-7 Salem Bye-Pass Road, (Near) Mahamariamman Temple Karur -639 002.
54. Jesu Arts and Science College (Co-Educational), Alangudi, Pudukkottai Dist. -622 301.
55. Kokila Arts & Science College (Co-education), Viralimalai, Manaparai Road, Pudukkottai
56. Kongu College of Arts & Science, Deeran Chinnamalai Nagar, Karur - 639 006.
57. Krishna College of Arts and Science, UGR Nagar, Kolluthannipatty, Melapaguthi Village, Kadavur (Tk), Karur (Dt.) -621 301
58. Kurinji College of Arts & Science, Green Ways Road, Tiruchirappalli - 620 002.
59. M.I.E.T. Arts & Science College, Gundur, Tiruchirappalli - 620 007.
60. Mahatma Arts and Science College, Ariyur Village, Illuppur Taluk, Pudukkottai District- 622 101
61. Maruthu Pandiyar College, Vallam (P.O.), Thanjavur - 613 403
62. MASS College of Arts and Science, Kumbakonam - 612 501
63. Meenakshi Chandrasekaran College of Arts & Science, Pattukkottai - 614 626
64. Meenakshi Ramasamy Arts and Science College, Udaiyarpalayam, Ariyalur-.621 804.
65. Modern Arts and Science College, 35A, Sannathi Street, Jayankondam, - 621 802
66. Mother Terasa College of Arts and Science, Mettusalai, Veerappatti Village, Illupur (PO), Pudukkottai Dt. - 622 102
67. Naina Mohamed College of Arts & Science, Rajendrapuram, Pudukkottai - 614 624
68. National Arts and Science College TrichyRoad, Jayankondam Ariyalur Dt. 621 802
69. Navalar Na. Mu. Venkatasamy Nattar Thiruvarul Kallori, Kabilar Nagar, Vennatrankarai, Thanjavur - 613 003.
70. Nethaji Subash Chandra Bose College, Thiruvarur - 614 001
71. Paventhar Bharathidasan College of Arts & Science, Pudukkottai - 622 515.
72. Rajagiri Dawood Batcha College of Arts & Science, Papanasam, Thanjavur - 614 207
73. S.K. Arts & Science College Thamaraipulam, Vedaranyam 614 809
74. S.K. College of Arts and Science, Melavasal, Mannargudi, Thiruvarur District- 614 014.
75. S.R.V. College of Arts & Science, Pirattiyur, Tiruchirappalli - 620 009
76. Sembodai R.V. Arts & Science College, Vedaraniyam T.K., Nagapattinam-614 809
77. Sir Issac Newton Arts and Science College, Pappakoil Village, Anthanapettai (PO),Nagappatinam Dt. - 611 001
78. Sri Amaraavathi College of Arts and Science, Velliannai, Karur - 639 908
79. Sri Meenakshi Vidiyal College of Arts & Science, Valanadu Kaikatty, Marungapuri Tk, Tiruchirappalli Dt. 621 305
80. Sri Sankara Arts and Science College, Asur, Kumbakonam, 612 501
81. Sri Venkateshwara College of Arts & Science, Peravurani - 614 804.
82. Srinivasan College of Arts and Science, Perambalur -621 212
83. SRM Trichy Arts & Science College, Irungalur Village, Mannachanallur TK, Tiruchirappalli - 621 105
84. St. Peter's Arts and Science College, Melaneduvai Post, Adimadam, Udayarpalayam Tk, Ariyalur (Dt) - 621 801
85. Sudharsan College of Arts Science, Perumanadu Villages, Iluppur Taluk, Pudukkottai Dt
86. Swami Dayananda College of Arts & Science, Tiruvarur - 612 610
87. Swami Vivekananda Arts & Science College, Sami Arul Nagar, Vallam, Thanjavur - 613 007
88. Vailankanni Matha Arts and Science College, ECR Main Road, Prathabaramapuram, Keelvelur TK, Nagapattinam 611 111.
89. Valluvar College of Science and Management, Kodaiyur, Aravakurichi Taluk, Karur - 639 003
90. Vikas College of Arts & Science, Inamkulathur, Srirangam TK, Tiruchirappalli 621 303.
91. ABC College of Arts and Science for Women, Erichy, Chithamaraviduthi Po, Aranthangi (Tk), Pudukkottai 614 622.
92. Aiman College of Arts & Science for Women, K. Sathanur, Tiruchirappalli - 620 021.
93. Annai Ayesha Arts & Science College for Women, College Main Raod, Valikandapuram, Perambalur Dt 621 115.
94. Annai Khadeeja Arts and Science College for Women, Kandanivayal Village, Edayathimangalam Po., Manamelkudi Tk., Pudukkottai (Dt.) - 6214620.
95. Annai Women's College, Aurobindo Nagar, Vennaimalai, Karur 639 006.
96. Arasu College of Arts & Science for Women, Panduthakaran Pudhur, Punjai Kadambankurichy Village, Manmangalam TK, Karur Dt. - 639006.
97. Auxilium College of Arts and Science for Women, Regunathapuram Village, Alangudi Taluk, Pudukottai Dt - 622 302
98. Bharathi Vidyalaya College of Arts & Science (Women), Trichy Road,
Thirugokaranam(PO), Pudukkottai - 622002
99. Bon Secours Arts and Science College for Women, Ruckmanipalayam, Mannargudi 614 001, Thiruvarur Dt.
100. Bon Secours College for Women, Vilar Bye pass Road, Thanjavur - 613 006.
101. Chidambaram Pillai College for Women, Manachanallur, Tiruchirappalli - 621 005.
102. Dr. M. Sivakannu Women's Arts & Science College, Ayakkaranpulam, Vedaranyam (Tk) Nagapattinam Dt. 614 707
103. Idhaya College of Women, Sakkottai, Kumbakonam 612 001.
104. Karur Velalar college of Arts Science for Women, SF.No. 14/3, Kuppam Village, Karur- Erode Main Road, Kuppam (PO), Aravakurichi Tk., Karur Dt. 639 111.
105. M.I.T. College of Arts & Science for Women, Annai Nagar, Musiri TK, Tiruchirappalli Dt. - 621 211.
106. Meera College of Arts and Science for Women, Thanjavur Main Road, Keelapalur Post, Ariyalur - 621707
107. Mother Gnanamma Women's College of Arts and Science, Varadarajanpet,
Jayankondam Taluk, Ariyalur District - 621 805.
108. Queens College of Arts & Science for Women, Punal Kulam, Kandarvakottai, Pudukkottai - 613 303
109. Rabiammal Ahamed Maideen College for Women, Thiruvarur - 610 002.
110. S.M.K. College of Arts and Science for Women, Kilakuvadi, Thuraiyur, Tiruchirappalli Dt.
111. Servite Arts and Science College for Women, T.Iadaiayapatti, Kalladai Village, Thogaimalai Panchayat, Karur - 621 313
112. Shrimati Indira Gandhi College, Tiruchirappalli - 620 002.
113. Sri Bharathi Arts and Science College for Women, Pudukkottai 622 303
114. Sri Sarada Niketan College of Science for Women, Karur - 639 005.
115. Sri Saradha College for Women, Perambalur - 621 212.
116. Subashakthi College of Arts and Science for Women, Sathiyamangalam Post, Kulithalai T.K., Karur Dt. - 639 120
117. Sulthana Abdullah Rowther College for Women, Thiruvarur - 614 101
118. Uswathun Hasana Mamaji Haji Abdul Latheef Women's College, Pallapatti, Karur - 639 205
119. Vinayaga College of Arts and Science for Women, Karuppur, Keelapaluvur, Ariyalur Dt-621 707
Rankings.
The National Institutional Ranking Framework (NIRF) ranked Bharathidasan University 77th overall in India and 53rd among universities in 2020.


Mechatronics

Mechatronics engineering also called mechatronics, is an interdisciplinary branch of engineering that focuses on the integration of mechanical, electrical and electronic engineering systems, and also includes a combination of robotics, electronics, computer science, telecommunications, systems, control, and product engineering.
As technology advances over time, various subfields of engineering have succeeded in both adapting and multiplying. The intention of mechatronics is to produce a design solution that unifies each of these various subfields. Originally, the field of mechatronics was intended to be nothing more than a combination of mechanics, electrical and electronics, hence the name being a portmanteau of the words "mechanics" and "electronics"; however, as the complexity of technical systems continued to evolve, the definition had been broadened to include more technical areas.
The word "mechatronics" originated in Japanese-English and was created by Tetsuro Mori, an engineer of Yaskawa Electric Corporation. The word "mechatronics" was registered as trademark by the company in Japan with the registration number of "46-32714" in 1971. The company later released the right to use the word to the public, and the word began being used globally. Currently the word is translated into many languages and is considered an essential term for advanced automated industry.
Many people treat "mechatronics" as a modern buzzword synonymous with automation, robotics and electromechanical engineering.
French standard NF E 01-010 gives the following definition: "approach aiming at the synergistic integration of mechanics, electronics, control theory, and computer science within product design and manufacturing, in order to improve and/or optimize its functionality".
History.
The word "mechatronics" was registered as trademark by the company in Japan with the registration number of "46-32714" in 1971. The company later released the right to use the word to the public, and the word began being used globally.
With the advent of information technology in the 1980s, microprocessors were introduced into mechanical systems, improving performance significantly. By the 1990s, advances in computational intelligence were applied to mechatronics in ways that revolutionized the field.
Description.
A mechatronics engineer unites the principles of mechanics, electrical, electronics, and computing to generate a simpler, more economical and reliable system.
Engineering cybernetics deals with the question of control engineering of mechatronic systems. It is used to control or regulate such a system (see control theory). Through collaboration, the mechatronic modules perform the production goals and inherit flexible and agile manufacturing properties in the production scheme. Modern production equipment consists of mechatronic modules that are integrated according to a control architecture. The most known architectures involve hierarchy, polyarchy, heterarchy, and hybrid. The methods for achieving a technical effect are described by control algorithms, which might or might not utilize formal methods in their design. Hybrid systems important to mechatronics include production systems, synergy drives,
exploration rovers, automotive subsystems such as anti-lock braking systems and spin-assist, and everyday equipment such as autofocus cameras, video, hard disks, CD players and phones.
Course structure.
Mechatronics students take courses in various fields:
Applications.
Physical implementations.
Mechanical modeling calls for modeling and simulating physical complex phenomena in the scope of a multi-scale and multi-physical approach. This implies to implement and to manage modeling and optimization methods and tools, which are integrated in a systemic approach.
The specialty is aimed for students in mechanics who want to open their mind to systems engineering, and able to integrate different physics or technologies, as well as students in mechatronics who want to increase their knowledge in optimization and multidisciplinary simulation techniques.
The specialty educates students in robust and/or optimized conception methods for structures or many technological systems, and to the main modeling and simulation tools used in R&D. Special courses are also proposed for original applications (multi-materials composites, innovating transducers and actuators, integrated systems, …) to prepare the students to the coming breakthrough in the domains covering the materials and the systems.
For some mechatronic systems, the main issue is no longer how to implement a control system, but how to implement actuators. Within the mechatronic field, mainly two technologies are used to produce movement/motion.
Subdisciplines.
Mechanical.
Mechanical engineering is an important part of mechatronics engineering. It includes the study of mechanical nature of how an object works. Mechanical elements refer to mechanical structure, mechanism, thermo-fluid, and hydraulic aspects of a mechatronics system. The study of thermodynamics, dynamics, fluid mechanics, pneumatics and hydraulics. Mechatronics engineer who works a mechanical engineer can specialize in hydraulics and pneumatics systems, where they can be found working in automobile industries. A mechatronics engineer can also design a vehicle since they have strong mechanical and electronical background. Knowledge of software applications such as computer-aided design and computer aided manufacturing is essential for designing products. Mechatronics covers a part of mechanical syllabus which is widely applied in automobile industry.
Mechatronic systems represent a large part of the functions of an automobile. The control loop formed by sensor—information processing—actuator—mechanical (physical) change is found in many systems. The system size can be very different. The Anti-lock braking system (ABS) is a mechatronic system. The brake itself is also one. And the control loop formed by driving control (for example cruise control), engine, vehicle driving speed in the real world and speed measurement is a mechatronic system, too. The great importance of mechatronics for automotive engineering is also evident from the fact that vehicle manufacturers often have development departments with "Mechatronics" in their names.
Electronics and Electricals.
Electronics and Telecommunication engineering specializes in electronics devices and telecom devices of a mechatronics system. A mechatronics engineer specialized in electronics and telecommunications have knowledge of computer hardware devices. The transmission of signal is the main application of this subfield of mechatronics. Where digital and analog systems also forms an important part of mechatronics systems. Telecommunications engineering deals with the transmission of information across a medium.
Electronics engineering is related to computer engineering and electrical engineering. Control engineering has a wide range of electronic applications from the flight and propulsion systems of commercial airplanes to the cruise control present in many modern cars. VLSI designing is important for creating integrated circuits. Mechatronics engineers have deep knowledge of microprocessors, microcontrollers, microchips and semiconductors. The application of mechatronics in electronics manufacturing industry can conduct research and development on consumer electronic devices such as mobile phones, computers, cameras etc. For mechatronics engineers it is necessary to learn operating computer applications such as MATLAB and Simulink for designing and developing electronic products.
Mechatronics engineering is a interdisciplinary course, it includes concepts of both electrical and mechanical systems. A mechatronics engineer engages in designing high power transformers or radio-frequency module transmitters.
Avionics.
Avionics is also considered a variant of mechatronics as it combines several fields such as electronics and telecom with Aerospace engineering. It is the subdiscipline of mechatronics engineering and aerospace engineering which is engineering branch focusing on electronics systems of aircraft. The word avionics is a blend of aviation and electronics. The electronics system of aircraft includes aircraft communication addressing and reporting system, air navigation, aircraft flight control system, aircraft collision avoidance systems, flight recorder, weather radar and lightning detector. These can be as simple as a searchlight for a police helicopter or as complicated as the tactical system for an airborne early warning platform.
Advanced Mechatronics.
Another variant is Motion control for Advanced Mechatronics, presently recognized as a key technology in mechatronics. The robustness of motion control will be represented as a function of stiffness and a basis for practical realization. Target of motion is parameterized by control stiffness which could be variable according to the task reference. The system robustness of motion always requires very high stiffness in the controller.
Industrial.
The branch of industrial engineer includes the design of machinery, assembly and process lines of various manufacturing industries. This branch can be said somewhat similar to automation and robotics. Mechatronics engineers who works as industrial engineers design and develop infrastructure of a manufacturing plant. Also it can be said that they are architect of machines. One can work as an industrial designer to design the industrial layout and plan for setting up of a manufacturing industry or as an industrial technician to lookover the technical requirements and repairing of the particular factory.
Robotics.
Robotics is one of the newest emerging subfield of mechatronics. It is the study of robots that how they are manufactured and operated. Since 2000, this branch of mechatronics is attracting a number of aspirants. Robotics is interrelated with automation because here also not much human intervention is required. A large number of factories especially in automobile factories, robots are founds in assembly lines where they perform the job of drilling, installation and fitting. Programming skills are necessary for specialization in robotics. Knowledge of programming language —ROBOTC is important for functioning robots. An industrial robot is a prime example of a mechatronics system; it includes aspects of electronics, mechanics, and computing to do its day-to-day jobs.
Computer.
The Internet of things (IoT) is the inter-networking of physical devices, embedded with electronics, software, sensors, actuators, and network connectivity which enable these objects to collect and exchange data. IoT and mechatronics are complementary. Many of the smart components associated with the Internet of Things will be essentially mechatronic. The development of the IoT is forcing mechatronics engineers, designers, practitioners and educators to research the ways in which mechatronic systems and components are perceived, designed and manufactured. This allows them to face up to new issues such as data security, machine ethics and the human-machine interface.
Knowledge of programming is very important. A mechatronics engineer has to do programming in different levels example.—PLC programming, drone programming, hardware programming, CNC programming etc. Due to combination of electronics engineering, soft skills from computer side is important. Important programming languages for mechatronics engineer to learn is Java, Python, C++ and C programming language.


Sheet of stamps

A sheet of stamps or press sheet is a unit of stamps as printed, usually on large sheets of paper based on the size of the printing plate, that are separated into panes that are sold at post offices. Where more than one pane is on a printed sheet they are arranged in a table-like arrangement. The spaces between the single stamps are all of the same size and provide space for a cut or perforation.
Size and format.
Today, a sheet of stamps is the most common way of arranging stamps on the impressed paper. The number of stamps on a sheet and the format of the sheet depend on the size and format of the individual stamps. Small stamps are usually printed on sheets of a hundred stamps, although the Penny Black, as with other pre-decimal sterling currency stamps, were printed in sheets of 240; larger stamps are printed on sheets of fifty, twenty-five or twenty, as is done by the USPS.
On November 13, 1994, the Deutsche Post changed the format of its emissions to sheets of ten stamps each, due to reasons of efficiency. The edges of these sheets are specially designed, making them a novel field of collecting.
Printing sheet.
In fact, the term printing sheet refers only to a part of the actual "printing sheet". This is because stamps are mostly printed in four connected sheets, to make best use of the stamp paper. At the post office counter, only the four separated printing sheets are sold. Therefore, the sheet of stamps is also called a counter sheet or pane, though improperly called a sheet of stamps.
Gutters.
The empty fields connecting the single counter sheets are called gutters. Normally they are separated in the middle after printing in order to obtain four counter sheets. The half empty fields or gutters then form the edge of the sheet. However, from many issues, unseparated gutters with connected stamps of the neighbouring sheets come on the market (stamp - empty field - stamp). These gutters may be either empty or printed, if printed edges were intended.
The philatelist makes a distinction between "horizontal and vertical gutters". A specific characteristic of the gutters is the "heart" of the printing sheet, where all four panes are connected. Gutters and hearts are very popular with collectors and reach high catalog prices, especially for classic issues.
Tête-bêche.
Single counter sheets do not always have to be separated by empty fields. Issues which were not intended to have edges were naturally manufactured without empty fields. To be able to distinguish between the single sheets better, the stamps were printed rotated 180° to each other along the separation line. Philatelists describe the two stamps which are upside down in relationship to each other as tête-bêche. Some issues have tête-bêches as well as gutters.
Like gutters, tête-bêches are very popular with collectors due to their scarcity and decorativeness.
Stamp arrangement and location.
The stamps are arranged on the sheet in a table with rows and columns. Due to this arrangement, the location of each stamp can be precisely determined. The philatelist counts the single stamps horizontally from left to right, but the post counts them vertically from top to bottom. Accordingly, the third stamp in the sixth row of a sheet of 10 x 10 would be the 53rd stamp of the sheet for the collector, but the 26th stamp for the post.
The first postage stamps of the UK, the Penny Black, were printed in sheets of 20 rows and 12 columns, but the location on the sheet was indicated by different letters in the bottom corners of each stamp. An "A" in the lower left corner indicated the first row, a "B" the second one, the "C" the third one, etc. The columns were indicated according to the same scheme in the lower right corner. Thus the top left stamp had the letter combination "A" - "A", the bottom right stamp had "T" - "L". As a result, 240 different stamps were made for each plate used. This was intended to prevent forgery.
Sheet edge.
The term "sheet edge" refers to the empty fields connected to the stamps and arranged around the sheet. These fields are often unprinted. However, in many cases, quite a bit of interesting information can be found on them, e.g. printing dates or the like. The most important inscriptions printed on the edges of the sheet are:
Specialities.
There are several specialities of the printing of sheets. The most important are:


General Magnaplate

General Magnaplate is a company that researches and produces surface coatings for metals.
One of its products, Hi-T-Lube, is recognized by the Guinness Book of World Records as the "world's most slippery solid".