Sensors Harvest Mechanical Energy

Georgia Tech professor Zhong Lin Wang holds an improved nanogenerator containing 700 rows of nanowire arrays

Researchers at the Georgia Institute of Technology have created the world's first self-powered sensors at the nanometric scale. Tiny generators embedding thousands of nanowires produce electricity whenever the wires are subjected to mechanical strain, and can be used to power microscopic sensors without the need for batteries.

The generators are large arrays of hundreds and even thousands of zinc oxide nanowires. The output voltage is proportionate to the mechanical strains being applied to the wires, and the team confirmed they can produce a peak voltage of 1.26 volts and peak power density of 2.7 milliwatts per cubic centimeter when the material on which they are deposited is subject a straining of a mere 0.19 percent.

The generators were manufactured via a chemical process designed to facilitate low-cost manufacture on flexible substrates. Moreover, extensive tests carried out on nearly one thousand of these nanogenerators showed that, thanks to the absence of moving parts, they can be operated over time without loss of generating capacity.

Gizmag