A Novel Self-Powered, High-Sensitivity Piezoelectric Vibration Sensor Based on Piezoelectric Combo Effect

This article presents a novel high-sensitivity vibration sensor based on the piezoelectric combo effect for continuous and real-time monitoring applications. The combo sensor uses a bimorph piezoelectric cantilever beam and a driver circuit. The sensor combines the direct and inverse piezoelectric effects to provide an in-phase force for increased sensor sensitivity. The sensor output voltage can supply the driver and the interface circuit. Nonlinear effects at the high input excitation levels have been investigated on the sensor performance. The fabrication process does not need post-processing, such as additional electrode etching or using piezo-composite material to increase sensitivity. According to the experimental results, the proposed sensor has a high sensitivity of ${S}$ = 1.33 V/g and a good linearity of ${R}^{{2}}$ = 0.99 in a wide range of input excitation levels. The presented method increases the sensitivity by about 3.6 times compared to the bimorph sensor, which is superior to the previous reports. The power densities of the combo and bimorph sensors are 2.54 mW/cm3 and 152 $\mu \text{W}$ /cm3, respectively, at the resonance frequency.