Imagine an artificial leg that can feel hot and cold, wet and dry, and even a caress! Scientists have tried all kinds of ways to make prosthetic limbs that can work with human nerves to make the limb not only more agile, but also to provide feedback sensations to the user. And all kinds of ways have failed to produce the desired results. Sandia National Laboratories, the University of New Mexico and the MD Anderson Cancer Center are working on a synthetic polymer to be used as a scaffold that severed nerve tissue can grow onto. Dr. Shawn Dirk explains how this substance is different from anything tried before.

Of course, researchers have already made plenty of efforts to directly integrate nerves and prosthetics. But, according to Dirk, they typically “didn’t use technology that was compatible with nerve fibers,” which are tightly bundled and flexible. “Nerves need to grow and move around; they’re not going to integrate well with a stiff interface.”

Yes, the material comprising the scaffold had to be flexible and fluid, but it also needed to be extremely conductive. Nerve signals are highly localized, and also very, very subtle. 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.

To create that ideal interface, Dirk and his colleagues developed their own biocompatible polymers, meant to mimic the properties of nerve tissue. The material is also porous, so that nerves can extend through it, and lined with electrodes, to vastly enhance conductivity.

The new polymer has tested well in rats, but its use in humans is still years away. Link

(Image credit: Flickr user Chris Corwin)