In these recent years, energy harvesting using piezoelectric material has been quite popular being research topic. As well as wireless sensor network (WSN) which are widely used. Due to wireless sensor application and environment, it is impractical to used fixed-energy alternative like battery or fuel cells with an expected lifetime of more than 10 years which once the sensors deployed usually preclude changing or re-charging the batteries. This paper presents energy harvesting by scavenging ambient energy, e.g. solar energy, thermal gradients and vibration. Vibration sources are ubiquitous and available in most places like air ducts, train, building structure and heart pace. Roundy et al have modeled, designed and built small cantilever-based devices with MEMS (Microelectromechanical system)technology using piezoelectric materials that can scavenge power from low-level ambient vibration sources and turn them into electricity to power the sensor node….

For further reading, please open the following link : Vibration Energy Harvesting