Assessment and evaluation of energy scavenging circuits using MFC

The rise in popularity of harvesting energy from ambient vibrations has made compact, energy dense piezoelectric generators commercially available. Much of the available literature focuses on maximizing harvested power through nonlinear processing circuits that require accurate knowledge of generator internal, mechanical and electrical characteristics and idealization of the input vibration source. Utilizing piezoelectric methods of harvesting energy require the conversion of AC to usable DC form. The purpose of this paper is to discuss and compare the various directions for rectification, which is the processing of the AC outputs of energy harvesting systems into regulated low voltage DC suitable for powering low power electronics. The three basic methodologies of energy harvesting, which will be compared, is full-wave bridge rectifier with passive diodes, full-wave bridge rectifier circuit with schottky diodes and Bi-MOS circuit for rectification which involves the combination of MOSFETs and BJTs. The experiment was carried out by using Macro Fibre Composite (MFC) patch on a cantilever beam.