Those boots weren’t just made for walking; they could also be the first of a new breed of energy-generating clothing and shoes. Thanks to bioengineers at the University of Auckland, bulky wearable generators that convert movement into electricity are a relic of the past. Taking their place? An inexpensive and lightweight rubber generator, based on artificial-muscle technology, that can harvest up to a watt of power when embedded in your shoes.


An artificial muscle, known as a dielectric elastomer generator, is a stretchy material that produces energy when deformed. Unlike traditional piezoelectric generators, which require quick, subtle motions to generate power, artificial muscles are better tailored to the “large, slow motions” we perform every day, according to Thomas McKay, a Ph.D. candidate working on soft generator research. (Case in point, they’re used to harvest energy from ocean waves.) The hand-pumped generators don’t require external circuitry for power supply and storage, either, allowing for even greater portability than previously possible.

Unlike traditional piezoelectrics, artificial muscles don’t require external circuitry for power supply and storage.

“The potential to produce lightweight, low-cost, wearable dielectric elastomer generators has been limited by the requirement for bulky, rigid, and expensive external circuitry,” McKay writes in the April 2011 issue of the journal Applied Physics Letters.

He describes building a plunger-like generator, a mere four inches wide, that can create 10 milliwatts of power. Comprising rubber membranes and carbon grease mounted in a Perspex frame, the compact device could easily slide inside a shoe or in the folds of a garment. Bonus: It costs less than $4 to make. Let the human-powered revolution begin!

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[Via Popular Science]