A replacement limb that moves, feels and responds just like flesh and blood. It’s the holy grail of prosthetics research. The Pentagon’s invested millions to make it happen. But it’s been elusive — until, quite possibly, now. The body’s own nerves are arguably the biggest barrier towards turning the dream of lifelike replacements into a reality. Peripheral nerves, severed by amputation, can no longer transmit or receive any of the myriad sensory signals we rely on every day. Trying to fuse them with robot limbs, to create a direct neural-prosthetic interface, is no easy task.