When asked at a recent conference what Additive Manufacturing was, Dr. Mike Fralix answered that is was merely the opposite of Subtractive Manufacturing! Additive manufacturing describes the act of adding materials together to create objects versus subtracting from larger pieces to form objects or parts. Many products are assembled from pieces cut from large rolls of fabric, blocks of wood or sheets of metal using the subtractive manufacturing method. Hand knitting is one of the oldest forms of additive manufacturing. The most talked about additive manufacturing process as of late is 3D printing, however there are other new modern additive processes such as full-garment knitting, laser sintering and electron beam welding. There are also some interesting bio-engineering processes such as growing human organs and skin, animal meat, leather, growing bricks from bacteria, and urea and clothes from yeast and sugar that are emerging. All of these new methods will revolutionize manufacturing, as we know it.
Full garment knitting (aka whole or complete garment knitting) is a process that starts with yarns and a 3D knit design and ends with a fully finished wearable garment or usable product. Two companies, Shima Seiki and Stoll produce knitting machines capable of creating these types of garments. Knitting a full garment can be more efficient, if the machine speed is good, in comparison to more traditional method of flat knitting panels of garments, such as sweaters, which often require a further step to sewing them together at the seams. Making the whole garment at once allows for some amazing (an otherwise impossible) design and structural capabilities and also drastically reduces wasted material.
Nike has debuted a similar concept with their Flyknit running shoes. The shoe ‘uppers’ are knitted using a 3D knitting process, which eliminates waste and produces a much lighter yet breathable product. The project team, consisting of engineers, material experts and designers, built in support structures where they are most needed for running, using different types of knit stitches and methods- something that would be impossible to do as elegantly by the traditional cut and sew method. I wouldn’t quite call this full garment knitting, as the soles still have to be attached to the upper – and are not being created by one machine- yet.
Additive Metal Manufacturing
Electron beam Direct Manufacturing is a new technology introduced by Sciaky that gives the capability to “print” metal parts using a laser beam. The laser beam, guided by a computer using a 3D CAD file, fuses a metal wire to create a whole part. After the part is created, it still must be finished - much as a cast metal part needs to be further refined. Sciaky’s EBDM machine can create large metal parts (up to 19’x4’), such as those used in the defense and aviation industries made of stainless steel and other high value alloys.
There is also a similar “metal printing” process that utilizes laser-sintering technology. It also utilizes a 3D CAD file to direct the beam to fuse metal powder into a finished part. Machines with this technology, such as those produced by EOS, can make small parts, molds and products. Metal powder is poured into the machine, and a beam fuses the part inside of the “sea” of powder. After the part has been created, the extra, un-fused powder can be reclaimed and reused. The part must be heat hardened and finished. Another similar technology, Laser Metal Deposition Welding, forces a stream of metallic powder into contact with a laser that is also used to weld layers of metal onto objects or weld pieces of metal together. Trumpf is a provider of these types of machines. As this technology becomes more widely used and the price decreases, consumers will eventually have the ability to print their own replacement metal parts for their cars or lawnmowers and the lead time for manufacturers to produce items that are out of stock will be reduced.
Breakthroughs in Bio-processes
On the frontiers of bio-engineering, researchers at Heriot-Watt University and Roslin Cellab have successfully used a 3D printer to print stem cells. They believe that this new breakthrough method, that preserves as well as replaces the delicate stem cells could, in the future, allow easier testing of drugs on actual human tissues and eventually lead to custom printed organs created from a patients own cells. Custom organs, such as trachea and bladder, made from scaffolds seeded with stem cells, have successfully been implanted in to patients over the last few years, but it is still an emerging technology.
The company, Modern Meadow, is working on the printing of raw animal meet for human consumption as well as bio-engineered leather to reduce the environmental impact and meet projections for global demand. Quotes on their webpage such as “Up to 20% of leather is wasted in manufacturing” and “It takes over 50 gallons of water and 75 sq ft of land to make 1 burger (Capper et. Al, 2011) show some of the sustainable advantages to synthesizing meat and leather.
Humble and ubiquitous bacteria could not only help us digest that bio-engineered meat, but might also be used to build the houses we live in and create the clothes on our backs. A discovery in the sands of Dubai by architect Ginger Dosier could lead to building bricks that are no longer baked at a high temperature to cure them, which requires a lot of energy. Instead using microbial-induced calcite precipitation (MICP), sand in a mold is bound together by bacteria and a series of chemical reactions, forming bricks. With some further experimentation to make the bricks harder, this could very well be the way building materials are made in the future.
Fashion designer Suzanne Lee is experimenting with making clothing out of the cellulose mat created by bacteria, yeasts and other microorganisms during a typical brewing of kombucha tea. The basic ingredients to grow this are, sugar, growth bath, living organisms, the right temperature and a week or so of fermentation. The bacteria create very fine strands of cellulose which all stick together and float to the top of the liquid, creating a slimy, rubbery mat on the surface. This mat can then be taken out, dried and sewn into clothing. There are some issues with it being very absorptive so it is not a commercially viable option at present, but she has an interesting TED talk that is worth viewing for more details.
As a colleague pointed out, so many other things in our daily lives have been revolutionized digitally. This includes photos, videos, music, maps, money, newspapers, and magazines. Naturally, other physical objects are next. Along with this revelation comes the inevitability of new methods, regulations, expectations, and technologies to enable the new ways of sharing, using, and capitalizing on this digitization. The success and cornering of the digital music and app market by Apple’s iTunes comes to mind, as does Kodak’s fatal decision to not enter the digital camera market. This revolution is another Darwinian one, where the adage “adapt or die” may very well continue to hold true.
So what could this mean for the future of retail? Will consumers share products online and print them at home, or purchase CAD files from retailers to print down the street at a local 3D printer? Maybe they will share patterns to grow their own clothes. There are already several websites to share 3D object files such as Thingverse, GrabCAD’s library, and more. Or perhaps manufacturing will become so high-tech that it replaces the ability to sew fashionable clothes at home. Only time will tell, but some of the ideas behind modern additive manufacturing methods explored in this piece will indeed revolutionize our daily lives in the not too distant future.