Get y0ur T-1000 jokes ready, because we're one step closer to liquid metal-powered people. As a team of Chinese biomedical engineers recently used an alloy to close the gap between severed sciatic nerves in frogs. In effect, it made electronic circuits out of nerves—and it worked.
Shockingly, this sci-fi solution is as simple as it sounds. Looking for a way to keep muscles active while nerves healed, the Tsinghua University researchers identified liquid metal as a highly conductive but also safe material to bridge the gap. They decided on the liquid metal alloy gallium-indium-selenium, a benign material that's liquid at body temperature. (This liquid metal is not to be confused with the brand-name wonder material Liquidmetal, which is not actually a liquid.) The liquid metal alloy is also highly conductive.
To test the alloy, the engineers applied an electric pulse to nerves in a frog leg so that the calf muscle would contract. They then severed the sciatic nerve and connected the two ends with either the liquid metal alloy or Ringer's solution, a mix of electrolytes that mimic body fluids. Sure enough, the Ringer's solution only carried the charge so far, while the liquid metal alloy transmitted the electrical signals about as well as the nerve before it had been severed. This means it could be used to protect muscles and nerves after an injury, and since it's metal, it can be easily removed with the help of an x-ray.
This is obviously the early stages of what could be an exciting new treatment for nerve injuries. It's also, arguably, the first step towards truly wired creature. Of course, we're probably closer to building a cyborg than you might think. [Technology Review]