The Energy Harvester - using vibrations to generate electricity

Science and music have no boundaries and the ecstasy that new symphonies or new inventions bring is always something that cannot be comprehended in simple words. One such innovation in the field of physics has been effected by a group of researchers at the University of Michigan. These electrical engineers have developed an energy harvester that can harness energy from vibrations and in turn convert it to electricity. However, what takes the cake is that this energy harvester is smaller in size than a penny and yet its power and efficiency is five to ten times greater than similar devices.

harvester generates electricity from vibration

The vibration energy harvester basically works on the principle of converting cyclic motions of factory machines into energy for powering wireless sensor networks which in turn can be assigned a multitude of functions. Designed to generate more than 200 microwatts of power, on exposure to just 1.5g of vibration amplitude, this device occupies barely 27 cubic millimeters of space. Additionally, the harvester also has a large bandwidth of 14 Hertz with a vibration frequency of just 155 Hertz, which makes it even more workable.

The current study entailed integrating a high quality energy harvesting piezoelectric material with circuitry to make power accessible. The piezoelectric material allows charge build-up in response to machine vibrations. The energy that’s therefore accumulated is stored in an ultracapacitor which does not need to necessarily stay charged (as is the case with other capacitors). Theoretically therefore, the harvester once installed can be left in place for a minimum of 10 – 20 years without maintenance.

"Wireless" sensors of today get their power supply from a local plug or battery. These sensors are considered "wireless" only because the output transmission doesn’t require wires. Moreover, being attached to a power source not just gives rise to costs incurred for installation and maintenance, but also towards monitoring and testing in addition to replacing the batteries which have a limited shelf-life. Considering these limitations, that affects the cost-benefit ratio in the long run, the alternative of energy scavenging provided by the energy harvester seems, but viable.

Proposed to be presented at the 16th International Conference on Solid-State Sensors, Actuators, and Microsystems (TRANSDUCERS 2011) to be held in June 2011 at Beijing, the implications of this research has evoked great interest in the power sector as the market for wireless sensor networks is expected to reach $450 million by 2015.

Via: Physorg