'Living' robots powered by muscle

From BBC NEWS:

"Tiny robots powered by living muscle have been created by scientists at the University of California, Los Angeles.

The devices were formed by 'growing' rat cells on microscopic silicon chips, the researchers report in the journal Nature Materials.

Less than a millimetre long, the miniscule robots can move themselves without any external source of power.

The work is a dramatic example of the marriage of biotechnology with the tiny world of nanotechnology. "