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It’s come a long way in a short time . . . by Dr David Maddison The latest in 3D Printing Three dimensional (3D) printing has been around since the 1980s but there have been many improvements to the technology since then, especially of late. This includes much lower printing costs, higher printing resolution, faster printing, improved materials and more material variety, the ability to print much larger parts and more user-friendly printers. D esign. Print. Assemble. Drive. That’s the slogan of Divergent 3D Blade, who created the 2015 concept car shown above. The driver sits in a 3D “painted” aluminium and titanium chassis – an example of what modern technology can achieve. 3D printing is also known as additive manufacturing, to indicate that parts are built up by adding more material onto them, distinguishing it from traditional machining processes used in manufacturing such as milling and turning, which start with a larger piece and then removes surplus material to arrive at a final object. Initially, the primary use for 3D printing was to quickly make prototypes of components to evaluate and test them before committing to a full manufacturing process. For example, a part could be made in plastic to test it for fit, functionality and appearance and then later manufactured in metal. While still used for this purpose, due to improved strength of materials and processes it is now possible to create objects directly that are structurally sound and suited for an end-use application such as aircraft, automobile or satellite parts. Processes have also been developed that make it possible to rapidly produce a large number of parts for a mass-production environment. While the terms 3D printing and additive manufacturing 12 Silicon Chip are loosely interchangeable, they have come to have somewhat separate meanings in the industry. 3D printing is commonly understood to refer to the lower end of the market, including domestic printers; additive manufacturing has come to refer to industrial-scale equipment and processes suitable for commercial design and production processes. However, there is some overlap and even disagreement with the terminology. For simplicity, we will refer to all these technologies as 3D printing in this article. Main types of 3D printing There are seven main types of 3D printing processes, as defined by the ISO/ASTM 52900:2015(en) standard and they are as follows: 1) Binder Jetting, an “additive manufacturing process in which a liquid bonding agent is selectively deposited to join powder materials” (see Fig.1).    In this process, a binding agent is deposited onto a powder bed to bind particles together, which will form the desired part. Once one layer has been finished, the powder bed is lowered and a new layer of powder is spread over the build area. The process then repeats until the object is finished.    One variation of this process uses sand or similar Australia’s electronics magazine siliconchip.com.au Fig.2: Dutch designer Joris Laarman has developed this Directed Energy Deposition process, enabling an industrial robot using welding techniques to create arbitrary metal structures in air. Fig.1: the Binder Jetting process. powder materials; another uses metal powder. Dimensional accuracy is typically around 0.2mm with metal or 0.3mm with sand.    It is a low-cost process with applications including making sand casting moulds and cores for metal casting (Sand Binder Jetting). Large objects can be produced. When metal is used (Metal Binder Jetting), the part can be finished off by heating in a kiln to sinter the component. Voids in the metal can then be filled with another metal that has a lower melting point. 2) Directed Energy Deposition, an “additive manufacturing process in which focused thermal energy is used to fuse materials by melting them as they are being deposited… Focused thermal energy means that an energy source (eg, laser, electron beam or plasma arc) is focused to melt the materials being deposited”.    This process is similar to welding; in one example, a wire spool is fed to an electric arc which melts the wire and deposits metal onto the piece being worked on, typically under the control of a robotic arm with five- or sixaxis control (see Fig.2). Very large objects can be made with relatively coarse accuracy. 3) Material Extrusion, an “additive manufacturing process in which material is selectively dispensed through a nozzle or orifice”.    In Material Extrusion, a filament of plastic is pushed through a heated nozzle which is moved in a predefined pattern onto a workpiece on a build platform. After one layer of plastic has been deposited, either the nozzle is moved away from the workpiece, or the workpiece is moved away from the nozzle, allowing further layers to be built up (see Fig.3).    The technology used is called Fused Deposition Modelling (FDM) or Fused Filament Fabrication (FFF). Dimensional accuracy is typically around 0.5mm. Parts can be brittle, depending on the material used, and not always suitable to withstand mechanical loads.    A variety of plastic types and colours can be used. This is the most common and cheapest form of 3D printing and Legend: 1) Filament 2) Filament Driver (Extruder) 3) Heated Nozzle 4) Figure 5) Build Platform. Fig.3: 3D printing a figure using Material Extrusion. Author: Wikimedia user Kholoudabdolqader. siliconchip.com.au Fig.4: the Material Jetting process. Build material and support material is ejected from print heads and cured by UV light after it has been deposited. The build platform is then lowered and the process repeated. Australia’s electronics magazine January 2019  13 Fig.6: the Sheet Lamination process. Image credit: Wikimedia user LaurensvanLieshout. Fig.5: the Powder Bed Fusion process, in which a laser fuses a powder layer in the shape of a slice of the desired object. The build platform is then lowered, covered with a fresh layer of powder and the process repeats. is typically used by the hobbyist. Additional structures often need to be printed to support overhanging areas during printing, then removed when printing is complete. 4) Material Jetting, an “additive manufacturing process in which droplets of build material are selectively deposited … Example materials include photopolymer and wax.”    Material Jetting is a process in which a photosensitive build material and a dissolvable support material is deposited on a build platform and then the build material is cured with UV light.    Layers are built up one at a time, as with other 3D printing processes (see Fig.4).    Deposition is similar to the process of an inkjet printer and is done line-by-line. A combination of both build material and support material can be used. The support material is designed to be washed away or otherwise removed at the end of the process. Typical uses for this technique are multicolour prototype production and creating medical models. An accuracy of 0.1mm can be achieved. Fig.7: the Vat Photopolymerisation process. Image credit: Scopigno R., Cignoni P., Pietroni N., Callieri M., Dellepiane M. (2017). “Digital Fabrication a) a light source, either a scanning laser or Techniques for light from a DLP device illuminates the Cultural Heritage: bottom of a tank (c) filled with photo-polymerising resin (b) which solidifies and creA Survey”. ates the workpiece (d) which is drawn from Computer Graphics the liquid by the build platform (e) Forum 36 (1): 6–21. DOI:10.1111/ cgf.12781. 14 Silicon Chip A roll of material (1) passes over a heated roller (2) and is then cut to shape with a laser beam (3) from a scanner and laser source (4 and 5) and compressed by the roller onto the printed piece (6). As each layer is deposited, the build platform (7) is lowered and the used material that has had the shapes cut from it is wound up on a take-up roll.    The resulting parts are brittle. Drop on Demand or DOD is a variation of this process. 5) Powder Bed Fusion, an “additive manufacturing process in which thermal energy selectively fuses regions of a powder bed”.    In this process, a metal or polymer powder layer is fused by a thermal energy source and as each layer is completed, the work platform is lowered and a new layer of powder is deposited and the process is repeated until the workpiece is finished (see Fig.5).    When creating metal objects, a laser is typically used for Direct Metal Laser Sintering (DMLS) or Selective Laser Melting (SLM), or an electron beam for Electron Beam Melting (EBM). Dimensional accuracy of 0.1mm can be achieved with metals such as aluminium, stainless steel or titanium. Fully functional metal parts can be directly produced for aerospace, medical or dental applications.      With polymers, the process is called Selective Laser Sintering (SLS). Nylon is typically used and the dimensional tolerance is 0.3mm. Functional parts can be produced. Powder bed fusion has the advantage that no support structures need to be printed as the powder supports any overhanging structures above it. 6) Sheet Lamination, an “additive manufacturing process in which sheets of material are bonded to form a part”. Sheet Lamination, also known as Laminated Object Manufacturing, is a process in which sheets of materials such as paper or foil are cut with a knife or laser Fig.8: the 3D-printer optimised antenna bracket for the Sentinal satellite, made from aluminium alloy. Image source EOS GmbH. Australia’s electronics magazine siliconchip.com.au Fig.10: this bicycle from Arevo has a 3D printed plastic frame. Fig.9: this shows how the design intended for traditional manufacturing was converted to a version optimised for 3D printing. Image source EOS GmbH and adhered together, building up one sheet at a time as the build platform is lowered with each layer deposited (see Fig.6). 7) Vat Photopolymerisation, an “additive manufacturing process in which liquid photopolymer in a vat is selectively cured by light-activated polymerisation”.    In Vat Polymerisation, a photosensitive liquid pre-polymer resin is polymerised or cured by the application of a light beam. As each layer is polymerised, the object being printed is lifted from the liquid. Dimensional accuracy of up to 0.15mm can be achieved (see Fig.7).    The two main technologies are Stereolithography (SLA) and Direct Light Processing (DLP). In SLA, a laser is used to draw the desired pattern of a given layer by driving it across the workpiece in the X an Y directions.    In DLP, the pattern for each layer is drawn all at once with a digital light projector. Good surface finishes are possible. Recent advances in the technology We will now take a look at some recent advances in 3D printing technology. Due to the vast number of 3D printed products being produced, it is impossible to cover all of them, so in some cases, only representative examples of each will be presented. Aerospace components Many Aerospace components can now be produced directly in their final form using 3D printing. Moreover, the component design can be optimised for strength and lightness by taking advantage of the unique capabilities of 3D printing. Computer software often decides the final shape of the Fig.11: this bicycle has a 3D printed stainless steel frame. It was made by students at TU Delft in the Netherlands, by welding of beads of material using a robotic arm and Directed Energy Deposition. siliconchip.com.au piece, working to specific constraints such as dimensions that are imposed by the designer. As no person decides the final shape, the design can appear somewhat “organic”, like shapes produced in nature. In one example, a bracket for a space satellite antenna was transformed from its original design, intended for production by traditional manufacturing techniques, to a design which takes advantage of 3D metal printing techniques. The 3D printed component weighs 940g compared with the traditional component which weighs 1600g. See Figs.8 & 9. Bicycles and bike tyres There are two claimants for the world’s first 3D printed bicycle frame. One is San Francisco-based Arevo (https:// arevo.com/) who made a plastic framed bicycle with a polymer called PEEK (polyether ether ketone) – see Fig.10. The frame is said to be stronger than titanium. The other contender is UK-based company Renishaw (www.renishaw.com/en/) who worked in conjunction with Empire Cycles to make the first metal 3D printed bicycle frame. The frame was made in sections in titanium and then the sections were bonded together (see Figs.12 & 13). An Australian company, Bastion Cycles (http://bastioncycles.com/) is making custom bicycles with 3D printed frame lugs (Fig.14). Another company, BigRep (https://bigrep.com/), based in Berlin, has produced an airless 3D printed bicycle tyre (Fig.16). BigRep also makes very large 3D printers, with a build volume of up to one cubic metre. Clothing Clothing is now being produced with 3D printing, many items with bizarre designs. Unfortunately, copyright restrictions by the designers prevent any images being shown here. Fig.12: the titanium sections of the Renishaw bike, in the form that they came out of the 3D printer. Australia’s electronics magazine January 2019  15 Fig.14: a 3D printed custom bicycle frame lug made by Australian company Bastion Cycles. Fig.13: the assembled Renishaw titanium bike.‑ Custom 3D printed shoes A company called Feetz (https://feetz.com/, “The Digital Cobbler”) is, or soon will be, making 3D printed shoes to order (see Figs.15 & 17). Their FAQ page is at: https:// feetz.com/faq To order shoes, the customer downloads an App to their smartphone and uses it to take three pictures of each foot. This provides enough information to generate a 3D model of each foot, which is used by a 3D printer to make the custom shoes. The shoes are designed to last the industry standard of 800km of walking or six months of wear. The Feetz YouTube channel can be seen at: siliconchip. com.au/link/aam3 Also see the independent early product review from May 2017 in the video titled “Feetz Shoes Review – 3D Printing Shoes”, viewable at: https://youtu.be/ Ta_1lTa55zo Digital Light Synthesis by Carbon Digital Light Synthesis is a vat synthesis 3D printing technique by a company called Carbon (www.carbon3d. com/). They make 3D vat polymerisation equipment with production rates suitable for mass production. Their 3D printing technology has enabled Adidas to make a shoe with a unique midsole which would be im- possible to make by any method other than 3D printing. The midsole is printed with a high-performance elastomeric polyurethane material (Fig.18). See the video titled “Carbon M1 Super Fast 3D Printer Demo” at https://youtu. be/O2thSsQrZUM 3D printing food Fused Deposition Modelling isn’t just used with plastics. It is also possible to use the same technique with edible substances. As a result, it’s possible to 3D print food so long as the ingredients can be pureed so that they can be squeezed through the extrusion nozzle. 3D printing of food allows great flexibility in the artistic presentation of food, as well as creating designs that would be difficult or impossible to do by conventional techniques. Unfortunately, the texture of the resulting food reflects its pureed origins, so there can be no chunky or chewy aspects to the creations as in regularly prepared food. Some examples of commercially available 3D food printers are: • the byFlow Focus (www.3dbyflow.com/home-en) • Choc Creator (http://chocedge.com/) • ChefJet – see Fig.20 (https://au.3dsystems.com/culinary /collaborations) • DISCOV3RY COMPLETE (www.structur3d.io/) Fig.15: Feetz brand 3D printed custom footwear. 16 Silicon Chip Australia’s electronics magazine siliconchip.com.au Fig.16: the 3D printed airless bicycle tyre from BigRep. • Foodini (www.naturalmachines.com/) – see Fig.19 • MMuse Touchscreen • several different machines by Procusini (www.procusini.com/) • Wiiboox Sweetin (www.wiiboox.com/3d-printerwiiboox-sweetin.php) • ZMorp Thick Paste Extruder (https://zmorph3d.com/ products/toolheads/thick-paste-extruder) NASA has been researching food for astronauts made with 3D printers to help provide variety for long-duration missions such as trips to Mars or stays on the International Space Station. A number of restaurants offer 3D printed food on the menus such as Food Ink (http://foodink.io/) in London, where all food, utensils and furniture are 3D printed; the Mélisse Restaurant (https://www.melisse.com/) in Santa Monica, California; La Enoteca at Hotel Arts in Barcelona; and La Boscana (http://www.laboscana.net/) in Bellvís, Spain. 3D printing houses It’s not only small items that can be 3D printed, but large items such as houses as well! 3D printed houses are generally built by much the same techniques as smaller objects but at a larger scale. The construction material is typically a paste-like material such as concrete (see below for an exception) that can be laid down in layers and that has enough mechanical strength to hold itself together while it sets. Fig.18: the midsole of the Adidas FutureCraft 4D is 3D printed using Carbon’s Digital Light Synthesis technology. siliconchip.com.au Fig.17: the sole of the Feetz Axis model 3D printed sneaker. It is important to note that the entire house is not built in one go; typically, the 3D printer forms the internal and external walls and possibly the roof. Services such as plumbing and electricity have to be installed manually as do fittings such as windows, doors, kitchen and bathroom cabinetry and so on. 3D house printers may be in the form of a super-sized desktop printer and operate in a linear XYZ coordinate system, or they may have a centrally pivoted rotating arm (see Figs.21 & 22). Perth company Fastbrick Robotics (www.fbr.com.au/) has developed the Hadrian X, a brick laying robot which can lay the bricks for the house in a fraction of the time that a person would (see Fig.23). While it does not work as a traditional 3D printer, in that individual pieces are laid down, it is fair to say it is a form of 3D printing. Unlike a traditional, modern house, in the construction model used for the Hadrian X, internal walls are made of special bricks as well, which are equivalent to about 15 standard bricks in volume. Human body parts Human body parts can be 3D printed. This includes prosthetic devices such as stick-on artificial noses or ears (Fig.24); prosthetic limbs (Fig.25); practice parts for medical students and surgeons (Fig.26); actual working biological organs such as bladders (Fig.27); and skeletal compo- Fig.19: in this example of 3D printed food, a “corn cob” is printed by a Foodini machine. This would be extremely difficult to create by normal means but is easy with 3D food printing. Australia’s electronics magazine January 2019  17 Fig.20: examples of 3D printed food novelty items made with the 3D Systems ChefJet Pro. nents such as replacement hips or sections of damaged or diseased bone (Fig.28). Other synthetic organs are under development, as well as more skeletal components. Biological 3D printers use much the same principles as regular 3D printers but instead of printing with polymers, they print biological solutions containing living cells and matrix materials (see Figs.29 & 30). 3D printing of human body parts as replacements for damaged or diseased organs or other areas is being heavily researched right now and the replacements are already occurring. There are different difficulty levels in printing human body parts. Flat structures such as skin are the easiest to print, followed by tubular structures like blood vessels and urethras and the next most complex are hollow organs like the bladder or stomach. The most complicated parts to print are organs with complex “plumbing” and many different cell types such as hearts, kidneys, livers and lungs. Human bladders produced by 3D printing are an example of an organ that is being produced and implanted in people now. This work was pioneered by Dr Anthony Atala at the Wake Forest Institute for Regenerative Medicine (WFIRM) in North Carolina, who has also engineered skin, urethras and cartilage structures in the lab. 3D printed bladders are used when a patient has a damaged, diseased or malformed organ and requires a functional replacement. A portion of good bladder tissue is taken from the patient and incubated to multiply the cells and Fig.22: the world’s first 3D printed house by San Francisco company Apis Cor, in conjunction with Russian developer PIK. 18 Silicon Chip Fig.21: Artist’s concept of the Apis Cor (http://www.apiscor.com/en/) house printer. The basic structure of the house (walls etc) can be built in 24 hours. See the video titled “Apis Cor: first residential house has been printed” at https://youtu.be/xktwDfasPGQ then 3D printed to create the shape of a bladder, a process which takes two months. There are now ten patients who have 3D printed bladders implanted, including a patient that has had an implant for 14 years. New sections of urethras have also been grown similarly and implanted in patients. The first attempts at the 3D printing of human tissues by WFIRM were made with a modified office inkjet printer, which is now in a museum. Kidneys and livers are the organs most in demand but also the most complex to produce and work is underway to develop these for implant. See this video for more details: www.ted.com/talks/anthony_atala_printing_a_human_ kidney Lower cost metal printing Just as the cost of plastic 3D printing has come down to make it affordable for either home users or smaller engineering establishments, so is the cost of 3D metal printing. Here are some lower cost metal printing machines. iro3D The iro3D (http://iro3d.com/) is a low-cost desktop metal printer costing around US$5,000 – see Fig.31. It is pos- Fig.23: FBR Ltd’s Hadrian X bricklaying robot, which can lay bricks for a house in a fraction of the time that a human would take. See the videos on their YouTube channel showing the machine at work: http://siliconchip.com.au/link/aam4 Australia’s electronics magazine siliconchip.com.au Fig.24: 3D printed prosthetic stick-on nose and ear. sibly the lowest cost 3D metal printer on the market. It is in relatively early stages of production and was invented and produced by Sergey Singov in the USA. At that price point, it would be affordable for some home users. The printer works by depositing in the desired form of metal powders for printing (the build material), along with sand (the support material) in the empty non-printed spaces, into a crucible in a process called Selective Powder Deposition (SPD). Filler metal such as copper or high carbon steel is then placed on the top of the printed metal and sand workpiece, along with coke and additional sand, to prevent the workpiece metal from oxidising. The ensemble is then baked in a kiln (not supplied); the filler metal melts and “soaks” the powdered metal workpiece, binding the powder together to yield a 100% solid metal component (Fig.32). The minimum height of a detail that can be produced is 0.3mm, the layer thickness, and the minimum width is 1mm (the pourer diameter). Metals that have so far been tested in this printer are highcarbon steel, copper-iron and copper-nickel while mild Fig.25: the EXO Prosthetic designed leg by William Root. The residual limb is 3D scanned and then a matching prosthetic limb is designed to match. It is printed with laser sintered titanium and is available in different colours. A video of FitSocket in operation can be seen at a video titled “The FitSocket”, at https://vimeo.com/93307423 steel, copper-silver, copper-gold, silver-gold, gold-nickel and silver-nickel are said to be possible as well. The designer has said that other metals such as aluminium, stainless steel and titanium would require more research and a kiln with a controlled atmosphere such as a vacuum or argon gas. The inventor estimates that postage cost for the unit to Australia is US$300-$400. Note that before you pursue 3D metal printing, you would need to satisfy yourself that the metallurgy of the components produced would be suitable for your application. See these videos for more details: • “3D Printing Metal with the Iro3D Desktop Metal 3D Printer - Solid High Carbon Steel Parts” – https://youtu. be/4FkzLs7cLes • “Selective Powder Deposition (SPD) in a nutshell” – https://youtu.be/IzIvxRObadw • “Just another 3D printed steel object” – https://youtu. be/2C2P5RQUPrU • The YouTube playlist for this printer can be seen at: http://siliconchip.com.au/link/aam5 Aurora Labs A Perth-based Australian company called Aurora Labs (https://auroralabs3d.com/) makes what is believed to be Fig.26: non-functional 3D printed organs for medical instruction and surgical practice that look and feel like the real thing and even “bleed”. The models are produced using 3D printing to create injection moulds which are then filled with hydrogel, a polymer substance which feels like human tissue. Bleeding is simulated with bags of a blood simulant. See the video titled “Simulated Surgery at URMC” at https://youtu.be/Ah7gJ4Vgr-w siliconchip.com.au Fig.27: a 3D printed replacement human bladder. Australia’s electronics magazine January 2019  19 Fig.28: there is a collaborative project between the Australian Government, RMIT University in Melbourne, the University of Technology Sydney (UTS), St Vincent’s Hospital Melbourne and the global medical technology company Stryker to produce “just in time” implants to precisely replace a section of diseased bone removed during surgery using a 3D printer. Currently, two operations are required due to the time required to produce the implant. Image credit: RMIT University. the most inexpensive Direct Metal Laser Melting (DMLM) machine in the world, the S-Titanium Pro, which is priced at US$55,000 (see Fig.34). The machine can produce layer thicknesses as little as 50 microns with an X-Y resolution of 50 microns and pieces of up to 200mm x 200mm x 250mm can be fabricated. A variety of metals can be printed such as stainless steel, bronze, titanium, Inconel, iron and nickel silicon boron alloys. See Fig.33 for examples of items that can be created by this machine. The lower cost of Aurora Lab’s machines are due to the use of twin CO2 lasers of 300W total power instead of costly fibre lasers, and also because of the use of an X-Y drive engine to scan the laser across the workpiece instead of a much more expensive galvanometer-based scan engine. In addition to manufacturing the metal printer, Aurora Labs intends to manufacture metal powders to use in the machines. The supply of powder for 3D metal printing is of particular concern as there is expected to be a world- Fig.29: a MakerBot 3D printer modified by Adam Feinberg at Carnegie Mellon University to print 3D biological structures for breast cancer research. The custom-made extruder component that prints hydrogel inks to create the structures was itself 3D printed. wide shortage as metal components come to be mass produced by 3D printing in the process known as rapid manufacturing printing (RMP), which requires special highspeed machines. Aurora Labs also has Rapid Manufacturing Printing machines under development which are twenty times faster than other similar machines and they are expecting to produce machines which are even faster than that. The first beta copies of RMP machines were due to be released toward the end of last year (2018). Additional attractive features of this machine include the use of open source architecture, so free open source software such as MatterControl 3D printing software can be used. Also, users of this machine are not restricted to the powder supplied by the manufacturer, as any powder that meets Fig.30: the envisionTEC 3D-Bioplotter System for biological printing. Fig.31: the iro3d printer which is possibly the lowest-cost 3D metal printer available right now. 20 Silicon Chip Australia’s electronics magazine siliconchip.com.au Fig.32: some sample metal components produced with the iro3d printer. the manufacturer’s specifications can be used. Both of these features make the machine very attractive for smaller users such as smaller engineering firms, university labs and for makers of medical implants. This machine is not designed to replace $400,000$500,000 units but is a “stepping stone” machine for organisations starting to 3D print with metal. Fig.33: examples of parts printed with Aurora Labs’ S-Titanium Pro. Note the detail inside the cutaway chess piece. Fig.34 [below right]: Aurora Labs’ S-Titanium Pro D metal printer. Various motor vehicles are now being or have been 3D printed. One such car that will supposedly be available for purchase this year is the LSEV by Italian car maker XEV (X Electric Vehicle; www.x-ev.net/) – see Fig.36. It will be produced in China by the 3D manufacturer Polymaker. The printing process used is FDM or Fused Deposition Modelling. In contrast to a regular car which typically has about 30,000 components, counting every nut and bolt, this car will have just 57. The car bodies are printed with Nylon and rubbery thermoplastic polyurethane for the bumpers. After the car bodies are printed, they go through a process called vacuum lamination in which a coating of 2mm thick Nylon film is put over the car bodies to hide the printed layers. This also eliminates the need for painting. Parts that are not printed are the chassis and drivetrain, glass and seats. The car is electric with a top speed of 69km/h and a range of 150km, and it weighs 450kg, which would make it suitable for city commuting and shopping trips. The company says that the postal service in Italy has commissioned 5000 of the cars and car leasing company ARVAL has ordered 2000. The price is expected to be 10,000 Euro or around A$16,000. Fig.35: the world’s first 3D printed motorcycle. The frame is 3D printed in aluminium and it has an “organic” look, not on purpose but because of the optimisation algorithms which produced this design without human intervention. Humans imposed certain constraints such as component dimensions and computer software then generated the shapes. Fig.36: the LSEV, the first mass-produced 3D printed car, said to go into production in 2019. See the video titled “Bringing LSEV to life - The 1st Mass Produced 3D Printed Car” at https://youtu.be/g4XAy9FIrvk Motorcycles The world’s first 3D printed motorcycle is the Light Rider. It is electric, with a top speed of 80km/h, a range of 60km and has an exchangeable battery (see Fig.35). It weighs just 35kg. It is made by the German company APWorks (www. apworks.de/en/). The company plans to make a small number of street legal bikes. Motor vehicles siliconchip.com.au Australia’s electronics magazine January 2019  21 Fig.38: the Local Motors LM3D Swim, another car with a 3D printed body. Fig.37: the 3D printed space frame of the Divergent 3D blade, which is made of aluminium and titanium, with some standard carbon fibre tubing components. Earlier vehicles While the LSEV is the first 3D printed car intended for mass production, the first “fully” (with printed chassis) 3D printed cars were the Divergent 3D Blade from 2015 (see Fig.37) and the Local Motors LM3D, also from 2015 (see Fig.38). Divergent 3D is based in Los Angeles and made the Blade using a variety of 3D printing techniques. It was intended as a technology demonstrator and they hope that other automobile designers will submit their designs to them for manufacture via 3D printing. The Blade has a 3D printed aluminium and titanium chassis, weighs 590kg with a 2.4l Mitsubishi Evolution X engine which produces 522kW running on petrol or CNG. The driver sits in the middle of the carbon fibre, aluminium and titanium chassis. The carbon fibre components, wheels, engine and certain other components are not 3D printed. The car has a top speed of around 320kph. You can see a very informative video titled “2015 Divergent Blade - Jay Leno’s Garage” at https://youtu.be/vPv7PwS50OE The Local Motors (https://localmotors.com/) electric LM3D Swim was intended to be put on sale in 2017 for a price of US$53,000 but it does not appear to have gone to market. 75% of the car is 3D printed and it consists of 80% ABS plastic and 20% carbon fibre. It takes 44 hours to print. You can see a build video titled “LM3D Swim – Safe. Smart. Sustainable. – 3D printed Car by Local Motors (2015)” at https://youtu.be/TKkXRlli-aw Fig.39: the URBEE, the first car to have a 3D printed body. 22 Silicon Chip One of Local Motors’ current offerings is the Olli 3D printed self-driving minibus that can be used in places like university campuses and can be called from a smartphone. Finally, the URBEE (https://korecologic.com/) was the first car with a 3D printed body in 2011 but it used a conventional chassis (see Fig.39). You can view a video titled “URBEE (1st 3D Printed Car Body)” at https://youtu. be/2YOCkd1aJ2c Multi-material and multi-colour 3D printing The Palette 2 from Mosaic (https://www.mosaicmfg. com/) is a device that splices pieces of filament of various lengths and colours together and feeds them to a standard 3D printer in a particular order. This allows many common 3D printers to print multi-colour and multi-material objects (see Fig.40). Nano-scale 3D printing 3D printing concepts can be applied at the ultra-small scale as well. Structures such as microbatteries, microelectronic, microfluidic, micro-optical and biochip components can be produced with a variety of materials such as metals and polymers (see Figs.42-46). Making 3D objects from mobile phone pictures It is possible to use your mobile phone or another camera to take multiple pictures of an object from different angles and use software on a computer to construct a 3D im- Fig.40: an example of a multi-colour object printed from a standard 3D printer using filament that has been spliced together by Palette 2. Australia’s electronics magazine siliconchip.com.au Fig.41: a team at the Wyss Institute at Harvard University and the University of Illinois at Urbana-Champaign produced this lithium-ion microbattery measuring about 1mm across using nano 3D printing techniques. After these electrodes (made of electrically conducting ink) were deposited, the device was filled with electrolyte and encapsulated. age of the object of interest. You can then 3D print a copy of that object. The following video shows how to do this with free software. It is titled “Photogrammetry - 3D scan with just your phone/camera” and can be viewed at https://youtu. be/ye-C-OOFsX8 This next video shows a different technique which requires a CUDA-enabled graphics processor (GPU). It is titled “How to 3D Photoscan Easy and Free!” and is viewable at https://youtu.be/k4NTf0hMjtY It shows how to construct a 3D model but does not show how to 3D print it. Several 3D scanning Apps for phones are available, both free and paid for, some of which can produce files for printing and others which require extra work to do so. Phlat printer The PhlatPrinter is an open source home-built CNC (computer numeric control) machine that can cut large sheets of foam to make model aircraft and other sheet materials such as wood and MDF. It can be used to make many other 3D items from sheet materials. For further details, see: www.phlatforum.com and https://openbuilds.com/builds/ phlatprinter-mk-3.5207/ Fig.43: screws and nuts with threads of 1.3mm outer diameter, printed with a Nanoscribe Photonic Professional GT. siliconchip.com.au Fig.42: microscopic metal parts 3D printed using laser sintering by the company 3D microprint (www.3dmicroprint.com/) RepRap The RepRap is a low cost, open source 3D printer that can print some of its own parts, making it partially selfreplicating. It was voted the “most significant 3D printed object” in 2017. Users are encouraged to make variations on the initial design so many have been created. https:// reprap.org/wiki/RepRap Vat polymerisation printers for hobbyist use There are a number of vat polymerisation (resin) printers now available for hobbyist use. Two low-cost printers that one website rated highly are the Peopoly Moai (https://peopoly.net/), which they rated as “best value”, and the Anycubic Photon (http://www. anycubic3d.com/), which they rated as the “best budget resin 3D printer”. The Peopoly is available as a kit in the USA for US$1295 or fully made for US$1995 while the Anycubic can be purchased in Australia from eBay for upwards of A$550 plus postage. SC Fig.44: some examples of nano 3D printed components made with the Nanoscribe Photonic Professional GT system. Note that 1µm is 1/1000 of 1mm. Image courtesy of Dublin City University Nano Research Facility. Australia’s electronics magazine January 2019  23