customization in 3D-printed devices, says McAlpine. In the field of nerve regeneration alone, the technology has the potential to help 200,000 people annually, according to a press release from the University of Minnesota. For McAlpine, it’s one small step in a giant leap for bionics that is a few years down the road.
Now hear this: A 3D-printed bionic ear
McAlpine cut his teeth, so to speak, in 3D-printed bionics several years ago when he and fellow researchers at Princeton integrated cells and electronics to print a bionic ear. “It was not just a piece of cartilage, which is amazing in itself, but it also had an electronic coil that received sound signals,” explains McAlpine. On that foundation, McAlpine imagines what is yet to come. “Instead of strapping on a small brick to your wrist—i.e., a smart watch—what if you could merge that technology into your body? A 3D-printing platform that integrates electronics would allow us to do that,” he says.
Currently, the most popular approach to merging electronics with the body was developed by John Rogers at the University of Illinois, says McAlpine. “He took silicon wafers and peeled off layers to the point where they become like tissue, which are then ‘tattooed’ to the skin.” ( PlasticsToday profiled Rogers’ Biostamp technology in March 2014. You can read about it in, “ The birth of cool wearable medical devices .")
“It’s a beautiful approach,” says McAlpine, “but it doesn’t have the 3D component. Even if the device curves onto the skin, it’s still a two-dimensional interface. 3D printing gives you the ability to interweave electronics and any other material in three-dimensional space,” explains McAlpine. That technology takes us a step beyond the 2D devices we are so familiar with—laptops, smart watches and cell phones. “Having that three-dimensional component is key, and 3D printing is the only tool we have right now that can do that,” says McAlpine.