Healing, terminator-style: Liquid metal could fix severed nerves

Biomedical researchers in China are taking a page from Hollywood, kind of, by using liquid metal to bridge the gap between the two ends of a cut nerve. It's about time. Medical researchers are borrowing a page from the speculative science and technology of 1991's "Terminator 2" to help repair severed nerves, Cnet reported. On Monday, a team at Tsinghua University in Beijing announced the promising use of liquid metal to bridge the gap between the two ends of a cut nerve. It's not quite the full-on malleable liquid-metal exoskeleton you might see under the skin of murderous robots from the future, but it is a futuristic way of improving on current methods of nerve rehab that could prevent long-term disabilities. The basic idea is that when a nerve is severed, the muscles at the distant end of that nerve are cut off from the brain and essentially immobilized, leading to potential atrophy. To keep those muscles from wasting away, neural signals still need to somehow be sent over the gap in the severed nerve to keep them functioning and fit while the nerve heals, which can be a very difficult and slow process. The popular method of getting signals to hop over that gap right now uses a solution of salts called Ringer's solution that mimics body fluids. Metal seems to be a better means of conducting those vital signals over that gap in the severed nerve, according to the research, which was done using a severed sciatic nerve connected to the calf muscle of a bullfrog. "[Ringer's] Solution could not be competitive with the liquid metal in the performance as functional recovery channel," reads the summary of the research, which cites "favorable fluidity, super compliance, and high electrical conductivity" among the benefits. In other words, metal better conducts signals from the brain and is likely to work well in surgery. But while a good dose of sci-fi alloy looks to be a better way to rehab than salty Gatorade in the nerves, there's still lots of testing that needs to be done on the liquid metal method of healing, particularly with respect to safety. The human body doesn't always take well to intrusions by metal in its various forms, but given the success of metal plates placed in the head to protect the skull, for example, that's obviously not a hard and fast rule, either. Whatever it means for the future of neurosurgery is still not quite clear, but it's good to know we're finally developing the technology to keep pace, should those nasty, shape-shifting Terminators from the future ever show up.