Bend it like Wu
Materials science and engineering professor Junqiao Wu and a team of researchers from Lawrence Berkeley National Laboratory have created a microscale actuator that is smaller than the width of a human hair and can bend like a finger. The actuator is made of a strip of vanadium dioxide, a material that significantly expands and contracts when exposed to small changes in temperature. By heating the strip with an electrical current or pulse of laser light, the researchers were able to cause it to flex with a force 3,000 times greater than human muscle of the same size. The researchers hope this development will lead to microactuators that act as pumps for drug delivery or as mechanical muscles in microscale robots, and perhaps become competitive with—or replace—the piezoelectric microactuators that are the current industry standard.