Self-powered operational amplifying system with a bipolar voltage generator using a piezoelectric energy harvester

Abstract

Piezoelectric devices previously studied usually generated a single voltage to power an electronic device. However, depending on the userʹs purpose, the electronic device may need dual power supply. Here, we report a self-powered bipolar voltage generator using a piezoelectric energy harvester with two piezoelectric devices. When a force is applied to the piezoelectric energy harvester, the two piezoelectric devices separately supply positive and negative voltages to the operational amplifier that requires dual power supply to amplify an AC signal that have positive and negative polarity. At the same time, the harvester supplies additional power to an electronic device through a DC-to-DC converter with an output voltage of 3.3 V. This technique proves the feasibility of applying the piezoelectric energy harvester to operational amplifying systems in the field of sound, earthquake, and sonar that require both bipolar and single voltages without external power sources.