"Poke a hole in a human and something remarkable happens. First of all, you go to jail. But meanwhile, the wound heals itself, filling in the missing tissue and protecting itself from infection. Poke a hole in a robot, however, and prepare for a long night of repairs. The machines may be stronger than us, but they're missing out on a vital superpower.
Until now. Researchers at Belgium's Vrije Universiteit Brussel report this week in Science Robotics that they've developed a squishy, self-healing robot. Cut it open, apply heat, let it cool down again, and the wound heals itself. While self-healing materials are nothing new, their application in so-called soft robotics—a relatively new kind of pliable machine that uses pneumatics or hydraulics to move—could be big. Think Terminator-style robots that automatically heal bullet wounds. OK, maybe don't think of that.
Seppe Terryn, Science Robotics
To build their squishbot, the researchers crafted an elastomer, a elastic variety of polymer. Its network of microscopic chains are held together by something called a Diels-Alder reaction, which is temperature-sensitive. So these bonds break when you heat them and reform as they cool. "On the microscopic level, there is enough mobility to seal the gap," says electromechanical engineer Seppe Terryn, lead author on the paper. "And then if we decrease the temperature again the entire network will be formed again." Think of melting down a cube of Jell-O, then putting it back in the fridge—the difference being that this polymer goes back to its original shape and strength after injury. Also, it's more expensive and less tasty…"