Research on Self-powered Sensors Based on Piezoelectric Energy Capture

Aiming to address the issue of sensor power supply in complex industrial environments, a self-powered sensor scheme based on piezoelectric energy capture is proposed. The self-powered system is composed of a cantilever piezoelectric structure and an energy management circuit, which can convert vibration energy into electric energy. According to the similarity between the differential equation of the piezoelectric cantilever beam and the second-order equation of the circuit, the equivalent circuit model of the piezoelectric cantilever beam is constructed. In LTspice, the LTC3588-1 energy management chip is equivalent to a voltage boost, rectifier and regulator circuit, and the equivalent circuit can output a stable 3.3V DC voltage through simulation. It is calculated that the wireless sensor module composed of ultra-low power RF chip nRF24LE1 and thermistor MF52 needs 5.116 mJ energy to transmit data once. LTspice simulation experiment data show that the energy storage capacitor in the equivalent circuit of the self-powered system periodically releases 8.342 mJ energy to meet the energy demand of the wireless module, which successfully verifies the feasibility of the self-powered wireless sensor scheme.