Prototyping makes its mark

Customisation is the key to rapid prototyping, and will help to move such technologies further into manufacturing, according to industry guru Terry Wohlers. In his annual report on the industry, he estimates that sales of ‘additive fabrication’ techniques – those such as selective laser sintering, which build products one layer at a time – have more than doubled in the three years to 2007, to top $1.1billion. “We expect rapid manufacturing to become the largest application of AF technology in the future,” says the report. During his keynote address at the recent TCT conference, Wohlers cited a number of applications that are pushing the boundaries of rapid techniques. One, the first hardware offering from Huntsman Advanced Materials, is the Araldite Digitalis. It uses highly focused UV light – rather than lasers – to cure resin into a multitude of parts. The breakthrough at the heart of the system is a micro-mechanical ‘shutter’, which focuses the light that creates the parts. The increasing simplicity – and falling price – of devices like this could create a completely new industry in the shape of the ‘neighbourhood manufacturer’, who uses rapid techniques to make customised products, he said. “These will be small companies serving their local community – or the world,” said Wohlers. “All you will need is a web connection and a 3D printer.” Rapid techniques have already leapt from prototyping to manufacturing in the medical industry – such as in the creation of bespoke hearing aid shells. But the next step could be into a whole new realm: artificial organs. This is the goal of US company Tengion, which has begun to use rapid manufacturing techniques to create 3D ‘scaffolds’ that will be used to replace diseased organs. “They’re using a 3D printer to make a ‘scaffold’ and build a piece of human tissue, which can then be implanted – with no danger of rejection,” said Wohlers. The biodegradable scaffold – created by putting collagen or polyglycolic acid through an inkjet printer – could be in the shape of a heart valve, kidney or entire bladder. The patient’s cells are ‘seeded’ onto the scaffold, which is then implanted. The cells grow into a healthy new organ as the scaffold slowly breaks down in the body. “Instead of waiting years for a transplant, you could ‘grow your own’,” said Wohlers. This may sound like science fiction, but Tengion has already carried out clinical trials. All of a sudden, those customised hearing aid shells begin to sound a bit mundane