Wait until Barry Bonds hears about this A micromachine that walks using muscles that it grew for itself has been developed in a US laboratory.The remarkable device could eventually lead to muscle-based nerve stimulators that let paralysed patients breathe without a ventilator, or to nanobots that clear away plaque from inside the walls of a human coronary artery.Scientists at the University of California in Los Angeles grew a length of muscle about 100 microns long on the underside of a silicon frame measuring 200 microns. The cells were taken from a rat's heart and grown in a culture that mimics natural biological conditions. The muscle contracts and relaxes by feeding on glucose in a solution, the contractions causing the tiny structure to shuffle along. Before, as the third member of Kid N' Play: After, hanging out with C. Evert Koop and an eagle:   ¶ 8:46:00 AM