Vibrational Energy Harvesting Devices

This paper reviews recent patents in the field of vibrational energy harvesting. The area is still not mature and there is a great potential for improving existing energy harvester designs. Piezoelectric transducers are seen to offer superior energy densities and the majority of patents discussed utilise such electromechanical systems. The bulk of work being carried out in this area is focused on increasing performance levels of the conventional cantilevered design. The patents reviewed are targeted at improving strain distribution along beams, techniques for tuning, widening the bandwidth of devices and improving performance for low amplitude and frequency sources. Conclusions are drawn regarding the future potential of various designs and the vibrational energy harvesting field in general.