Vibrational power.

While vibration is the White Whale of any NVH engineer, a little rattle may mean a little more energy and a little less weight in future vehicles.

That's the claim from AdaptivEnergy (Hampton, Virginia; www.rlpenergy.com) and its Joule-Thief piezo-based "energy harvester" module, a matchbook-sized circuit that "feeds" on vehicle vibrations so fine they can't be felt by humans, yet will generate power in return. Just how much juice? During a one-minute cycle, the module is capable of churning up to 35 mJ (millijoules) from 1 grms (G Force root-mean-square) load acceleration at 120 Hz. That translates to about 0.8 milliwatt in 60 seconds. Not much, but enough to power a wireless sensor. AdaptivEnergy notes that most background vibrations are below 0.2 grms, under which the circuit could generate more than 10 mJ of energy.

The module could prove a helpful stowaway for auto manufacturers interested in lowering vehicle curb weight. AdaptivEnergy claims the device has the potential of knocking off hundreds of pounds of electrical wiring harnesses, as well as the batteries to power sensors embedded in hard-to-reach door panels and roofliners.

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