Piezoelectric generator creates power from shoes
By Jude Garvey
23:11 April 29, 2010

Could a tiny piezoelectric generator provide convert enough energy from walking to power your mobile devices?
Could walking or running generate enough energy to power your cell phone or GPS device? Dr. Ville Kaajakari has developed an innovative piezoelectric generator prototype small enough to be embedded in the sole of a shoe that's designed to produce enough power to operate GPS receivers, location tags and eventually, even a cell phone.
Harnessing kinetic energy is not without its challenges because it’s difficult to generate enough energy to power today’s applications. That’s where Kaajakari's invention - which has recently been featured in the MEMS Investor Journal - comes in.
The shoe generator uses a low-cost polymer transducer with metalized surfaces for electrical contact. Traditionally, ceramic transducers are hard and therefore unsuitable to use in shoes but Kaajakari's generator is soft as well as strong so it could replace a normal heel shock absorber without loss to the user experience.
According to Kaajakari, the new voltage regulation circuits can convert the piezoelectric charge into a usable voltage and combined with the polymer transducer give a time-averaged power of two milliwatts per shoe on an average walk - that’s comparable to lithium coin/button cells and enough to power running sensors, RF transponders and GPS receivers.
"This technology could benefit, for example, hikers that need emergency location devices or beacons," said Kaajakari. "For more general use, you can use it to power portable devices without wasteful batteries. Ultimately, we want to bring up the power levels up to a point where we could, in addition to sensors, charge or power other portable devices such as cell phones."
It will be interesting to see if Kaajakari’s inventiveness pays off – will shoes of the future be capable of charging mobile devices, and at the same time will our footsteps power the buildings we walk through?
Via: MEMS Investor Journal.
Sometimes I wish I was 20 years younger so I'd be able to see technologies like this develop...
Can this kind of kinetic generator be put in tyres of cars and therefor produce extra energy?
@Facebook User, I don't think you should put it in tyres, as it would then create added resistance, which would increase fuel consumption (power required), and due to
You could absolutely put this in the shocks or the brakes of a vehicle.
if we use those generators in the stair cases or veranda or in roads instead of placing it in the shoes,will that generate more amount of power?......
How to store the electrical energy that is generated by applying pressure on a piezoelectric sheet for future use?
This isn't "free energy," and the device doesn't "create energy." It actually makes the person wearing the shoe work just a little bit harder, and converts that extra kinetic energy to electricity. It probably doesn't add as much extra effort as wearing those 5 lb ankle weights, and does convert the energy created into a useful form, but let's not encourage the "energy from nothing" or "perpetual motion" nutjobs.
How about motor mounts for an automotive engine? Would it not absorb some of the stress as well from the mechanical vibrations normally given off by the engine that is not welcomed on a vehicle anyway? Smoother operation with more power output.
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The concept of Piezoelectric generators in shoes has been floating around for years, with no products yet available.
I hope Dr. Ville Kaajakari has indeed solved the challenges, and products will be forthcoming, since after all, the vast majority of people do walk.