A nanoscale robot with a clutch can engage or disengage its engine, allowing for more precise control over its motion. It could be used to kill harmful cells.
Tiny clutches already exist in nature – for example, the bacterium Bacillus subtilis has long, hair-like structures called flagella, each attached to a rotating molecular engine. “Once [the bacteria] arrive at their target area, they will take a rest,” says Jinwoo Cheon at…