A new microchip the size of a coin can harness energy from footsteps. Researchers at MIT have come up with this microelectromechanical (MEMS) device that can harvest energy from low frequency vibrations.
A new energy harvesting device converts low-frequency vibrations into electricity. The device, the size of a U.S. quarter, is shown mounted on a stand. Image Credit: Arman Hajati
The minute chip the size of a U.S. quarter coin has a bridge like structure which is attached to the chip on either end with a single layer of lead zirconate titanate (PZT) added. It has the ability to generate 100 times the power of other similar devices currently in existence.
Sang-Gook Kim, study leader and professor of mechanical engineering at MIT, and Arman Hajati, co-author and Ph.D student at MIT have increased the frequency range and power density of the microchip which can draw power from all kinds of vibrations in the environment.
Anything from the humming of machinery to the footsteps on a busy walkway can be translated into power. The concept is not news as many current technologies use it, but they have problems which do allow the sort of efficiency that this microchip does.
Sang-Gook Kim said that there were wireless sensors widely available, but there is no supportive power package. For instance the chip may be only charged from a fixed frequency and if it increases or decreases the chip goes off. This will not happen in the new microchip due to its increased range of frequency which translates into a greater opportunity to produce power.
Hajati said that the new design was able to generate 45 microwatts of power with only one layer of PZT. He added that their target was at least 100 microwatts, and that's what all the electronics guys were asking them to get to. Hajati said for monitoring a pipeline, if you generate 100 microwatts, you can power a network of smart sensors that can talk forever with each other using this system.
Read more about the device here.