UCLA scientists ahve developed a micromachine that walks using muscles that it grows for itself. The device could lead to nanobots that clear away plaque from inside the walls of a human coronary artery or to muscle-based nerve stimulators that let paralyzed patients breathe without a ventilator.

They built the micromachine by etching the silicon structure using photolithography before coating the frame with a polymer and selectively depositing gold and chromium. The polymer acts as a mold for the muscle to grow along and the gold provides points to which the growing muscle cells can attach.

The muscle 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.