Piezoelectric conversion and energy harvesting enhancement by initial energy injection

This letter reports a concept for enhancing the conversion abilities of piezoelectric materials based on initial energy injection, as well as its application to energy harvesting. Unlike conventional energy conversion approaches, this concept considers a pulsed bidirectional energy flow between the source and the storage stages. The presented technique shows an "energy resonance" effect that can bring up the gain in terms of harvested energy up to 40 (20 using typical components) compared to standard energy harvesting methods. Such a system thus allows a significant reduction in active materials required for the conception of autonomous devices supplied by ambient energy.