Robots built from living tissue are set to crawl through your body to detect disease, deliver drugs and perform surgery. In march this year, American electrical engineer and scientist professor Rashid Bashir published a blow-by-blow account of how to design and make a muscle-powered biological machine. Dubbed `biobot', the walking, 6mm-long device can be powered by muscle cells, controlled with electrical and optical pulses and could one day roam your body to deliver drugs, detect disease or remove pieces of tissue.