University of Texas at Austin researchers report the first method for manipulating the rotation speed and Schematic of the white light projection system. Source: University of Texas at Austinmechanical motion of nanomotors with simple visible light stimulation. The ability to effect rotational reconfiguration could lead to new controllable nanoelectromechanical and nanorobotic devices for drug delivery, optical sensing, communication and microfluidic automation. Nanodevices with tunable speed have already been tested in drug delivery applications, but using light to direct mechanical motions has wider implications for nanomotors and nanotechnology research.

Depending on its intensity, light can stop, increase or reverse the rotation orientation of silicon nanomotors in an electric field. The stimulus from a laser or light projector at strengths varying from visible to infrared switches mechanical motion of rotary nanomotors among various modes instantaneously and effectively.

The researchers were able to distinguish semiconductor and metal nanomaterials by observing their different mechanical motions in response to light with a conventional optical microscope.

The research is published in Science Advances.