Via LiveScience, the Inside Science News Service reports that scientists at the Virginia Polytechnic Institute, in Blacksburg, Va., have recently developed a tiny piezoelectric device that is able to harness the power generated by small vibrations and could become of tremendous use in tomorrow’s small-scale robots, probes and appliances.
Collecting the energy of small vibrations could potentially lead to the development of self-charging batteries. This type of battery could be particular useful inside portable game consoles, mobile phones, laptops or radio instruments. Carrying them around makes them shake and vibrate, albeit on a small scale.The VPI device could harness this energy, and essentially recharge the batteries as the object is being moved from one place to the other in a bag or pocket. Details of the new apparatus appear in the journal Applied Physics Letters.
The breakthrough in this work has to do with getting the piezo devices to function at a wider range of vibration frequencies. They describe their units as “piezomagnetoelastic structures.” Compared to typical piezoelectric devices, the VPI “broadband” energy harvester yielded a 200% increase in the open-circuit voltage amplitude, which should in turn deliver an 800% increase in the power amplitude.
A lot of groups are thinking about new ways to use piezos in energy-harvesting applications, and broadband devices could open up a lot of new applications. For instance, crystals could be placed under highly circulated sidewalks, and could provide the energy requirements of the stores located on that specific street. Essentially, they can be placed anywhere where continuous activity takes place.
The VPI work is being sponsored in part by the Air Force. The USAF plans to use the devices to harness the vibrations that appear at the tip of the wings of unmanned reconnaissance planes. Capturing this energy could allow the vehicles to stay in the air longer. NIST is the other funder, and the agency plans to use the piezoelectrics on bridges, hopefully to harness the power of intense traffic bottlenecks.