3-D printing opens up brave new world of instant manufacturing
Three-dimensional models of buildings, and products such as shoes and even plane parts, are created before your eyes
Visitors who have booked a session at a novel photo booth in Japan are experiencing perhaps the closest possible thing to Star Trek-style teleportation. Each is scanned, then recreated in miniature using a 3-D colour printer.
Of course, no one actually moves between places, and the model people are not magically alive. Yet the process is just one example of the rapidly developing and expanding field of 3-D printing. While this and some applications, such as chocolate printing, are akin to novelties, its uses include rapidly making complex prototypes, and even creating plane parts.
In Hong Kong, the Housing Department is embracing 3-D printing to create models from 3-D architectural design software. It has done plastic printouts of individual flats complete with plumbing, cross sections of buildings, and a new housing development. These help in presenting design concepts to the public. One 3-D prototype showed how an excavation site would appear, helping the contractor fine-tune the work sequence.
"We can build models in 3-D software and view it on the screen - it is more fascinating to print them out, and make models we can touch, and a group of people can see from various angles and discuss," said Alex Ho Kwing-kwong, the department's information technology manager.
"The models are accurate, and we can print various pieces and see how they fit together, simulating real life construction. This can lead to redesigns at an early stage, saving costs."
3-D printing involves creating solid objects layer by layer. Lasers have played a key part in its development, and the first 3-D printers employed an ultraviolet laser beam that was aimed at a liquid photopolymer. The photopolymer solidified in places where the beam hit it, and the beam moved on to gradually build the printout. Other techniques have also emerged, such as print heads which extrude molten plastic or even chocolate that quickly hardens, and lasers that fuse powdered material together.
At first, 3-D printing was used for "rapid prototyping" as part of a computer-aided design process. Though rapid by comparison with using tools to create intricate models, printing each prototype took several hours.
Now there is a shift towards products, including unique fashion designs for shoes and clothing made from plastic and nylon, as well as jewellery. Customised dental crowns can also be made with 3-D printers, offering perhaps far closer fits than dentists have achieved manually.
3-D printing enables the creation of highly intricate designs that might be difficult or impossible to make in other ways. Metal bone implants can be fashioned with internal structures akin to the lattices of real bone - so they are relatively lightweight, and better integrate into patients' bodies. Rounded channels are readily built within metal structures, leading to a British manufacturer producing a high-performance gearbox for racing cars, and F-15 fighter jets featuring printed parts, including air ducts.
A new jet engine - the LEAP - that is being developed by a joint venture between GE Aviation of the US and Snecma of France will include several printed parts, partly because making them requires less metal than with conventional techniques, and they can be lighter.
"The aim is to not only produce the parts for a drone, for example, but build a complete vehicle that can fly right out of the printer," wrote Neil Gershenfeld, an expert in the field and professor at the Massachusetts Institute of Technology, in the December issue of Foreign Affairs.
Such advanced manufacturing can create spare parts in remote locations - and not just on earth. US space agency Nasa is fostering SpiderFab additive manufacturing techniques, through which spacecraft will deploy 3-D printing to make structures that form large antennae supporting a deep space communications network, as well as far larger solar panels that can be launched using rockets. And once spacecraft reach other celestial bodies, 3-D printing may play a key role. Nasa funded a study showing that it is possible to make simple tools and spare parts from simulated moon rock that was powdered, then melted with a laser.
Going beyond 3-D printing, Gershenfeld said digital fabrication was the new revolution. But it is not just for manufacturers and space explorers.
"Digital fabrication will allow individuals to design and produce tangible objects on demand, wherever and whenever they need them," he wrote. "Widespread access to these technologies will challenge traditional models of business, aid, and education."
Individuals can try creating their own objects through online services or even with their own printers. Shapeways, Sculpteo and 3dprintuk are among companies that can transform your designs into 3-D objects, perhaps as gifts, or items you can offer for sale. You can also choose from existing designs, such as for smartphone cases, to which you can add a personal touch.
If you want to do it yourself, 3-D desktop printers are becoming more affordable, and more capable. They include a new model from MakerBot with a Star Trek-inspired name: Replicator 2. Roughly the size of a microwave oven, this has a window through which you can watch as plastic objects are created. Unlike Star Trek, you cannot ask it to make dinner, but you could create a plate to eat from as you ponder the possibilities for printing.
Martin Williams is a Hong Kong-based writer with a PhD in physical chemistry from Cambridge University