Cited research: Nature Nanotechnol. doi:10.1038/nnano.2010.128 (2010)
Light particles carry momentum but, individually, not enough to move a physical object. Now Xiang Zhang and his colleagues at the University of California, Berkeley, have found a way of putting light to work. The team designed a nanometre-scale gold 'motor' with a physical structure that maximizes the strength of its interaction with light at specific wavelengths.
The light acted like a person pushing a swing, making the motor spin. The torque generated was strong enough to visibly rotate a micrometre-sized square silica disc (pictured) attached to the motor. The researchers say that the motor could eventually be used as the basis for tiny wireless devices. G.B.