Sep 8 2010
Researchers at the University of California and the Lawrence Berkeley National Laboratory of US Department of Energy have developed a new nano-size light mill motor. The direction and rotational speed of the nano-size light mill motor can be controlled by tuning the light waves’ frequency. The light mill motor may help design a new generation of nanoscale devices such as nanobots, nanoelectromechanical systems, and nanoscale solar light harvesters.
Ming Liu, left, Xiang Zhang, center, and Thomas Zentgraf
Xiang Zhang was the principal investigator of the project and worked along with Ming Liu and Thomas Zentgraf to develop the nanoscale light mill motor. Zhang is the Director of UC Berkeley’s Nano-scale Science and Engineering Center.
The light mill is able to operate efficiently because metallic structures can improve the light force applied on the matter when the incident light waves reverberate with the plasmons. The light mill was developed from gold using a structural design to increase the interactions between light and matter.
In addition, the metamaterial-type structure generates a torque on the nano-size motor via the induced orbital angular momentum. The four-armed motor supports two resonance modes namely 1700 and 810 nm that allow the directional change.