Advances in Prosthetics Could Fuse Nerves with Fake Limbs
The biggest barrier to making lifelike prosthetics a reality is the body’s own nerves, which severed by amputation, can no longer transmit or receive any sensory signals.
But now a team of scientists believe they have overcome this barrier. They are trying to fuse severed nerves with robot limbs, to create a direct neural-prosthetic interface. Their research is still in the early stages, but if successful, it would yield artificial arms and legs that can move with agility; recognize changing temperature; and restore even subtle sensations of touch.
Dr. Shawn Dirk and his colleagues set out to develop a synthetic substance that could act as a scaffold and support tissue growth. The material for the scaffold had to be flexible and fluid, but it also needed to be extremely conductive. An effective neural-prosthetic interface would need to transmit thousands of different signals per second to mimic the behavior of a real limb and its relationship to the brain and body.
Dirk and his colleagues have developed their own interface out of biocompatible polymers meant to mimic the properties of nerve tissue. The material is porous, so that nerves can extend through it, and lined with electrodes, to vastly enhance conductivity.
When surgeons placed the scaffolds onto the severed leg nerves of rats, it did not take long before the rats’ own nerve fibers started to grow through the scaffold and fuse back together. Even better, the synthetic material was not rejected by the rats’ immune systems.
This finding marks a huge improvement over previous research efforts, although a direct neural-prosthetic interface is still years away. But if this polymer holds up in subsequent tests, it will mean far more lifelike prosthetics, and a real chance of incorporating an artificial limb into an amputee’s sense-of-self.