A new method for controlling the rotation of nanowires will likely lead to tiny mixers, motors, and other microscopic devices. Researchers at Johns Hopkins University made videos of their spinning nanowires, which are only about 5 millionths of a meter long (ten times smaller than the diameter of a human hair). Some of the videos are available at the links below.
The researchers used electrodes to create rotating electric fields that spun the wires suspended in water. In some case the wires were attached to a substrate, creating minuscule fixed motors. In other cases, the wires were unattached and simply spun freely in the water.
The researchers spun gold, platinum, nickel, and carbon wires at precisely controlled rates up to 1800 revolutions per minute. They predict that higher rotation rates are possible, but could not be adequately measured with their experimental equipment. According to the researchers, the technology will help manipulate micrometer scale objects, aid in the study of microorganisms, and lead to a host of micro electromechanical (MEMS) machines.
Watch a video of nanowire motor attached to a substrate (27M).
Watch a video of spinning, free nanowire (5M).
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Publication: D. L. Fan et al., Physical Review Letters, Forthcoming article
Source: American Physical Society
