Imagine coming up with a way to power an iPod by converting the energy from walking or jogging into electricity. That’s the idea behind new nano-technology research funded by the U.S. intelligence community that could potentially turn spies into self-powered electricity machines.
Professor Michael McAlpine of Princeton University — who won funding as part of the Intelligence Community Post-Doctoral Fellowship program — is leading the effort. His research uses a type of piezoelectric crystal, called PZT, which produces an electric current when exposed to pressure.
Until now, researchers have been unsure how to make the crystals biocompatible. Manufacturing piezoelectric crystals requires heat that can exceed 1,000 degrees, so they’re tough to embed into temperature-sensitive materials, like rubber or plastic. So McAlpine’s team used nanotechnology, creating ribbons of the crystals on a substrate — 100 strips in a single millimeter — and then embedding them into silicone rubber. The result is a flexible strip of “piezo-rubber” that’s 80 percent efficient at converting mechanical energy (like what’s generated from walking) into electricity.
McAlpine tells Danger Room that a single PZT crystal, implanted into a shoe, could theoretically generate around enough to operate an iPod. Now imagine that instead of a single crystal, the entire shoe’s insole is lined with strips of PZT, that can convert most of the body’s energy into usable power.
Next up for the intel-funded researchers are prototype devices and some number crunching, to figure out exactly how much money the government agency could save if it switched to crystal-based people power.
More than just charging up intel gadgets, the research has clear applications across the military, including easy power harvesting for troops working in isolated, far-out terrain. But McAlpine is also anticipating widespread civilian use. Most importantly, perhaps, is replacing batteries on implanted medical devices, like pacemakers. The strips would harness power from the lungs to control the heart, and work perpetually without needing replacement parts.
That technology is likely a decade away, but the team anticipates producing sensors that operate using the piezo-rubber within a few months.
[Photo: Frank Wojciechowski]
