Researchers develop tiny, autonomous piezoelectric energy harvester



People have long been using piezoelectric devices to harvest energy in everything from dance floors to parking lots, but a group of European researchers have now shown off some novel uses for the technology at the recent International Electron Devices Meeting that could see even more of the self-sufficient devices put to use.


Their big breakthrough is that they've managed to shrink a piezoelectric device down to "micromachine" size, which was apparently possible in part as a result of using aluminum nitride instead of lead zirconate titanate as the piezoelectric material, thereby making the devices easier to manufacture. Their first such device is a wireless temperature sensor, which is not only extremely tiny, but is able to function autonomously by harvesting energy from vibrations and transmit temperature information to a base station at 15 second intervals.


Of course, the researchers say this is just the beginning, and they see similar devices eventually being used in everything from tire-pressure monitoring systems to predictive maintenance of any moving or rotating machine parts.


Such implementations were installed in several clubs in Europe. The dance floor uses piezoelectricity where crystal and ceramics create a charge to generate electricity. Those nightclubs have a "bouncing" floor made of springs and a series of power generating blocks which produce a small electrical current when squashed. As dancers move the floor up and down to squeeze the blocks, the current is fed into nearby batteries which are constantly recharged by the movement of the floor. The electricity created in this way is used to power parts of the nightclub such as the sound and lighting.


In Rotterdam for example, Club Watt also houses an energy harvesting dance floor which generates power for the clubs' lights, the average dancer making around 20 watts of electricity. That electricity is used to power the light show in and around the floor.