These mini-bots were made for walking: Cells power biological machines

These mini-bots were made for walking: Cells power biological machines: They're soft, biocompatible, about 7 millimeters long -- and, incredibly, able to walk by themselves. Miniature "bio-bots" are making tracks in synthetic biology. The walking bio-bots demonstrate forward-engineering functional machines using only hydrogel, heart cells and a 3-D printer. The bio-bots could be customized for specific applications in medicine, energy or the environment.