Fiber-based energy harvester potentially turns garments into generators
( 01 Jun 2008 )
By Matthew Miller
Researchers at the Georgia Institute of Technology have developed a textile-based generator that could enable garments to convert the wearer's movement into electricity to power personal electronic devices.
The researchers coax billions of zinc-oxide nanowires to grow radially from a Kevlar fiber, yielding a structure they liken to a bottle brush. A generator features two such fibers arranged in parallel. One of the fibers gets an additional coating of gold that allows it to serve as the electrode. Employing the same basic principles as an earlier harvester, the generator creates electrical energy via the piezoelectric effect when movement causes the two fibers to rub together (see “Energy harvester generates continuous nanoampere current,” EDN, May 24, 2007).
The researchers have measured 4 nA of current and 4 mV of output voltage from a generator employing 1-cm fibers. They estimate that, with design improvements, a square meter of fabric should be able to generate 80 mW. One major barrier to commercialization remains, the team admits: Zinc-oxide is vulnerable to water, so the technology still needs a mechanism for washing-machine survival.
Georgia Institute of Technology, www.gatech.edu
Caption
Researchers sewed nanowire-encrusted fibers into garments. When someone jostles the garment, the wires produce electricity.
