Wang is creating piezoelectric nanowires that generate electricity using tiny environmental vibrations; he believes they could power implantable medical devices and serve as tiny sensors.These devices could provide the fundamental building blocks that would allow the creation of a new area of nanoelectronics. The nanopiezotronic mechanism takes advantage of the fundamental property of nanowires or nanobelts made from piezoelectric materials: bending the structures creates a charge separation positive on one side and negative on the other. The connection between bending and charge creation has also been used to create nanogenerators that produce measurable electrical currents when an array of zinc oxide nanowires is bent and then released.

A ZnO nanowire can also be used as a semiconductor, one of the core components in a field-effect transistor (FET), the key switching structure in nanoscale sensors and devices. In this capacity, the nanowire bridges the source electrode on one end and the drain electrode on the other. Applying an electrical potential to a third electrode, known as the gate, controls whether current can pass through the semiconductor.

Wang and colleagues, including postdoc Xudong Wang and graduate student Jinhui Song, have already used this architecture to create pressure sensors with the ability to measure forces in the nanonewton range

"The potential applications are tremendous," Wang enthused. Nanopiezotronic devices could some day cover airplanes and space shuttles in a skin of wireless pressure sensors, he said. Nanopiezotronic generators could be put into knee patches on military fatigues and the sole of combat boots, creating power for soldiers on the march.He thinks nanopiezotronics is going to be more than just a new word. "This should be a whole new field," he remarked

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