Living robots made from frog skin cells can sense their environment

A microscopic, living robot that can heal and power itself has been created out of frog skin cells. Xenobots, named after the frog species Xenopus laevis that the cells come from, were first described last year. Now the team behind the robots has improved their design and demonstrated new capabilities. To create the spherical xenobots, Michael Levin at Tufts University in Massachusetts and his colleagues extracted tissue from 24-hour-old frog embryos which formed into spheroid structures after minimal physical manipulation. Where the previous version relied on the contraction of heart muscle cells to move them forward by pushing off surfaces, these new xenobots swim around faster, being self-propelled by hair-like structures on their surface.