Modern prosthetics enable millions of amputees to pick up an apple, but the sensation of holding that apple is still missing. Stanford chemical engineer Zhenan Bao has set out with a team of researchers to develop a new "skin" that could imitate skin's nerve sensors. Bao's skin would allow amputees to feel and move at the same time with bendable prosthetics.
To get a sense of just how incredible Bao's feat is, consider how your regular sense of touch works: Inside your skin are millions of nerve receptors. These receptors gather information about force, pain, and temperature. The receptors then send electrical impulses to your neurons (nerve cells). The impulses pass rapidly from neuron to neuron, to the spinal cord, and finally to your brain. The brain then has the job of translating the incoming signals. To work properly, Bao's skin had to replicate that entire sequence, all with an adaptable, flexible material that still would be durable enough to avoid interruption of the process.
It may still be in concept, but the logistics that Bao and his team have hurdled through already are significant. Their theory and process can be read in more detail at Inc. and at Bao Research Group.
Bao stresses that the skin is still only in the proof of concept phase, and that much more work is required to get the full touch capability most people naturally have. She still has to develop and incorporate systems that will mimic the remaining five types of biological sensing mechanisms regular skin holds. But already, the basic, two-layer foundation Bao has makes such additions theoretically feasible, and her team is partnering with PARC (of Xerox) to adapt inkjet printing technology that would make the skin practical over a large area. Not only that, but Bao's plastic fabric also should be able to "heal" and power itself. It might take time, but molecule by molecule, it's coming.