Today's most advanced prosthetic limbs can restore one's ability to manipulate objects, but there's still a wide berth between that and the ability to feel. Inventors have found ways to simulate this, but may not have to for long: a new "scaffold" could bridge the gap between severed nerves and machine limbs.
Wired's Katie Drummond reports that a coalition of researchers from Sandia National Laboratories, the University of New Mexico and the MD Anderson Cancer Center based in Houston, Texas are working on a scaffold that damaged nerves can grow into, bridging the gap between the human body and a machine limb. A connection like this would allow the body to pull in data from, say, a robotic arm, and for the arm to respond to the body's impulses and signals. As great as it sounds, it's also just as elusive to researchers.
The difficulty here goes beyond just being able to communicate information between nerves and a limb. Your body moves: you twist your arms, shake them and move them all about. In other words, the connective lattice needs to be durable, and in more ways than one.
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.
Early tests with rats were promising as rats' nerves grew through the scaffolds, just like Dirk and his team planned. Unfortunately, there's still plenty of hurdles to top before we have a system whereby the human body grows tissue to incorporate a machine limb as if it were one of its own.
A breakthrough of this kind would "give amputees their bodies back" according to the project's Dr. Shawn Dirk, who added that "nerves need to grow and move around; they're not going to integrate well with a stiff interface." Of course, like any announcement that sounds like science fiction, we're still years from this. Even still, it's a promising, exciting early development.