3D PRINTING Third Edition Christopher Barnatt ExplainingTheFuture.com First published by ExplainingTheFuture.com® For press, rights, translation and other enquiries, please e-mail [email protected] Copyright © Christopher Barnatt 2016. The right of Christopher Barnatt to be identified as the author of this work has been asserted by him in accordance with the Copyright, Designs and Patents Act 1988. Disclaimer While every effort has been made to ensure that the content in this book is as accurate as possible, no warranty or fitness is implied. All trademarks included in this book are appropriately capitalized and no attempt is made or implied to supersede the rights of their respective owners. Contents Preface: Beyond the Hype 1. The Revolution Continues 2. 3D Printing Technologies 3. The 3D Printing Industry 4. Direct Digital Manufacturing 5. Personal Fabrication 6. Bioprinting 7. Brave New World? Glossary 3D Printing Directory Further Reading Acknowledgements About the Author Preface: Beyond the Hype 3D printing transforms digital models into physical reality by building them up in layers. When the first edition of this book was published in May 2013, the idea of ‘additively manufacturing’ things in this manner had just started to capture the public imagination, with the popular press reporting that it would soon be possible for anybody to 3D print almost anything. Indeed, in another 2013 book called Fabricated: The New World of 3D Printing, Hod Lipson and Melba Kurman wrote that the field was moving ‘faster than the speed of light’, with technological advances taking place ‘in huge leaps and bounds’. By the time that the second edition of this book was published in November 2014, the mainstream appraisal of 3D printing had changed dramatically. To industry insiders it remained clear that innovations were accruing at a steady pace. But the popular perception was that all of those claims made in 2013 had been no more than hype. Most journalists subsequently abandoned ship, apparently surprised that personal fabricators capable of producing anything they could imagine were not yet on sale. Since late 2014 investors have also been spooked, with the share prices of many 3D printing companies having fallen dramatically. The now-widespread view that 3D printing has been over-hyped remains to the field’s detriment. As one of those who strove to bring 3D printing to mainstream attention, it is also a matter that I feel a need to specifically address. Back in 2013, I gave the first edition of this book the subtitle The Next Industrial Revolution. It is therefore not a surprise that, a year or so later, I ended up in the firing line of those journalists and academics who believed that false hopes had been raised. While labelling 3D printing as the Next Industrial Revolution, in both the first and second editions of this book I nailed my futurist colours to the mast in a fairly precise manner. Specifically, I noted that: … 3D printing is not going to replace all forms of traditional manufacturing. 3D printing will be ‘revolutionary’ even if it changes how perhaps 20 per cent of things are manufactured, transported and stored. The key thing for us to try and foresee is therefore just which industrial activities 3D printing is most likely to ‘revolutionize’, as well as those which are more probable to remain untouched. The idea that a technological development should be labelled ‘revolutionary’ if it changes how 20 per cent of things are manufactured, transported and stored is, I think, a very reasonable proposition. Back in 2013, I was also very strongly of the opinion that, within two decades, 3D printing would be used directly or indirectly in the manufacture of about 20 per cent of products. Occasionally in 2014 and 2015 I did start to believe the naysayers and to doubt whether this will actually occur. But the more that I study the development of 3D printing technologies and the 3D printing industry, the more convinced I become of my previous ‘20 per cent in 20 years’ prediction. Today, I am therefore once again staunchly of the view that a 3D printing revolution is on the cards. There are two reasons that I have cast my doubts aside. Firstly, it is clear that the composition of the 3D printing industry is in transition. For its first few decades the sector was dominated by ‘pure play’ startups – like 3D Systems and Stratasys – who created and brought to market the world’s first 3D printing technologies. Such companies also continue to innovate. Yet they are no longer alone, with very large, traditional manufacturing corporations – including Canon, Groupe Gorgé, HP, Kinpo, Ricoh and Toshiba – now entering or about to enter the fray. These companies are already bringing a great deal of financial and innovative muscle to the table, and will subsequently help to make 3D printing more widely utilized and cost-effective. The fact that all of these firms have chosen to enter the marketplace since 2013 also has to signal their belief in a large and profitable near-future 3D printing industry. The second reason for my rekindled faith is the continued invention of new technologies. Not least, in May 2016 a 3D printing method called nanoparticle jetting (NPJ) was showcased by Israeli pioneer XJet. As we shall see in chapter 2, this can directly produce highly accurate metal parts via an inkjet-style process. Nanoparticle jetting may therefore prove transformative in the low-run production of certain metal components. Even more significantly, the very recent announcement of nanoparticle jetting ought to provide a powerful reminder that the 3D Printing Revolution is likely to be based, at least in part, on technologies and processes that are yet to be invented. There are going to be many more watershed innovations in the next 20 years. In 1939 the first TV sets to go on sale in the United States were showcased at the World Fair in New York. These early TVs cost between $200 and $600 (or about the same as an automobile), and had rather fuzzy, five inch, black-and-white screens. Most of those who attended the World Fair subsequently dismissed television as a fad that would never catch on. After all, how many people could reasonably be expected to spend a large proportion of their time staring at a tiny, flickering image? The mistake made by those who dismissed television in 1939 was to judge a revolutionary technology on the basis of its earliest manifestation. Over 75 years later, those who believe that 3D printing has been over-hyped are in danger of making exactly the same error. Current 3D printing methods are certainly far too niche, too slow and too costly to change the world. But this will not stop next generation technologies from transforming the manufacturing landscape. With this last point firmly in mind, the goal of this book is to explain the practicalities and potential of 3D printing both today and in the future. From the outset, I am unashamedly assuming that 3D printing will help to drive a revolution in local, on-demand and highly customized manufacturing. Even if you disagree, I trust that you will find my work a valuable guide to the 3D printing industry, its current technologies, and their existing applications. But over the following seven chapters, I hope to more broadly convince you that we stand on the brink of something very special indeed. Christopher Barnatt, November 2016. 1. The Revolution Continues The 3D Printing Revolution is starting to materialize. According to market research group CONTEXT, in 2015 the 500,000th 3D printer was shipped, with the millionth unit expected to be sold in 2017. 3D printing is also just starting to be adopted as an end-use manufacturing technology. For example, in 2016 GE began selling an aircraft engine with 3D printed fuel nozzles, an Atlas V rocket launched into space with 3D printed parts, both Under Armour and New Balance sold small batches of partially-3D-printed sports shoes, and Organovo started to commercially ‘bioprint’ human kidney tissue. Absolutely the 3D Printing Revolution is in its infancy. But very solid foundations continue to be laid. Across history there have been many technological revolutions, all of which have progressed through three distinct phases. The first has been that of ‘conceptualization’, where visions and ideas have been generated that have defined the road ahead. Each technological revolution has then entered a phase of ‘realization’, during which time apparently impossible ideas have started to be turned into at least some form of operational reality. Finally we have arrived at a phase of ‘mass commercialization’, where businesses have learnt how to manufacture and operate a new technology in a robust and highly cost-effective manner. So where does 3D printing sit on the technological revolution continuum? Well, today the idea of using a 3D printer to turn a digital file into a physical object has propagated widely and is well understood. Indeed across disciplines as diverse as engineering, law, economics, business, geography and fine art, there is already much debate concerning the potential implications of being able to routinely share objects across the Internet for 3D printout on demand. Clearly we are a very long way from the day in which personal 3D fabricators may bring capitalism to an end by putting the means of production into the hands of the majority. Yet there can be no doubt that the 3D Printing Revolution has already been rigorously conceptualized. Further, we have already invented a fairly wide range of methods for fabricating solid objects by printing them out in many thin, successive layers. In fact, the most established 3D printing technologies have been around for decades. The 3D Printing Revolution is therefore making at least some progress when it comes to its practical realization. While 3D printing continues to advance, I would contend that it is still at least ten years away from its final revolutionary phase of mass commercialization. Granted, as we shall see across this book, 3D printing pioneers are now using the technology to fabricate all kinds of things. Yet right now – at least as an end-use manufacturing process – 3D printing remains limited in its commercial application to a few niche markets. Specifically, these are sectors that are prepared to pay a premium to engage in low-run, customized or personalized production, or to manufacture items that cannot be made using traditional methods. The above point noted, we should remember that a decade ago no industrial sector was reporting the sale of final products made in whole or part using a 3D printer. The fact that this is now occurring in any marketplace is therefore impressive. As new 3D printing methods are developed, and as older processes become faster and cheaper, we should therefore expect 3D printing to accelerate toward mass commercialization in the late 2020s or early 2030s. The most innovative pioneers are also set to take advantage of 3D printing well before that. 3D PRINTING TECHNOLOGIES So how, you may be wondering, does 3D printing actually work? Well, to a large extent, the processes involved are no more than a logical evolution of the 2D printing technologies already in use in a great many offices and homes. Most people are familiar with the inkjet or laser printers that produce most of today’s documents or photographs. These create text or images by controlling the placement of ink or toner on the surface of a piece of paper. In a similar fashion, 3D printers fabricate objects by controlling the placement and adhesion of successive layers of a ‘build material’ in 3D space. It is indeed for this reason that 3D printing is also known as ‘additive layer manufacturing’ (ALM) or ‘additive manufacturing’ (AM). To 3D print an object, a digital model first needs to exist in a computer. This may be created using a computer aided design (CAD) application, or some other variety of 3D modelling software. Alternatively, a digital model may be captured by scanning a real object with a 3D scanner, or derived from a 3D scan that is later manipulated with CAD or other software tools. Regardless of how a digital model comes into existence, once it is ready to be fabricated it needs to be put through some ‘slicing software’ that will divide it into a great many cross sectional layers that are typically about 0.1 mm thick. These digital slivers are then sent to a 3D printer that fabricates them, one on top of the other, until they are built up into a complete 3D printed object. Figure 1.1 illustrates a 3D model in the popular, open- source slicing software Cura, while figure 1.2 shows the same model being fabricated on an Ultimaker 2 desktop 3D printer. Exactly how a 3D printer outputs an object one thin layer at a time depends on the particular technology on which it is based. As I shall explain in depth in chapter 2, already there are a great many 3D printing technologies. This said, most of them work in one of four basic ways. Firstly, there are 3D printers that create objects by extruding a molten or otherwise semi-liquid material from a print head nozzle. Most commonly this involves extruding a molten thermoplastic that very rapidly sets after it has left the print head. Other extrusion- based 3D printers manufacture objects by outputting molten metal, or by extruding chocolate or cake frosting (icing) to 3D print culinary creations. There are also 3D printers that extrude concrete, a ceramic paste or clay. A second category of 3D printer creates object layers by selectively solidifying a liquid resin – known as a ‘photopolymer’ – that hardens when exposed to a laser or other light source. Some such ‘photopolymerization’ 3D printers build object layers within a tank of liquid. Meanwhile others jet a single layer of resin from a print head and use ultraviolet light to set it solid before the next layer is added. A few of the 3D printers based on the latter technology are able to mix several different photopolymers in the same print job, so allowing them to output colour objects made from multiple materials. Most notably, the latest such 3D printer – the J750 from Stratasys – offers a palette of 360,000 colour shades, and can fabricate objects in a mix of different materials including ‘rubber-like’ and ‘digital ABS’. A third and very broad category of 3D printing hardware builds object layers by selectively sticking together the granules of a very fine powder. Such ‘granular materials binding’ can be achieved by jetting an adhesive onto successive powder layers, or by fusing powder granules together using a laser or other heat source. Various forms of powder adhesion are already commonly used to 3D print in a wide range of materials. These include nylon, wax, bronze, stainless steel, cobalt chrome and titanium. A final category of 3D printer is based on lamination. Here, successive layers of cut paper, metal or plastic are stuck together to build up a solid object. Where sheets of paper are used as the build material, they are cut by blade or laser and glued together. They may also be sprayed with multiple inks during the printing process to create low-cost, full-