Piezoelectric Nanogenerator Enabled Fully Self-Powered Instantaneous Wireless Sensor System

Abstract

Self-powered real-time wireless Sensor Networks (WSNs) are vital for smart manufacturing, intelligent healthcare, and smart cities. Compared with triboelectric nanogenerators (TENGs), piezoelectric nanogenerators (PENGs) have smaller dimensions and can be easier to integrate into ICs, offering broader applications. However, developing a fully self-powered instantaneous wireless sensor system with PENGs poses significant challenges, and it is yet to be realized. Here, we present a novel PENG based, self-powered, instantaneous wireless (PSIW) sensor system. The integration of the PENG with an RLC sensing circuit facilitates the spontaneous generation of oscillating signals encoded with sensing information. To address the high internal impedance issue of PENGs, a piezoelectric voltage driven electronic switch is employed, ensuring that the oscillating signal's frequency and amplitude remain highly stable and resistant to environmental variations. The system's signal frequency modulation is analyzed under varying capacitances and inductances, with further exploration of the effects of coil distance, coil rotation angle, and coil offset distance. This sensor system is subsequently applied to strain and bending monitoring, as well as to wearable electronics to monitor elbow swing, wrist bending, walking, running and squatting. Results showed that the PSIW sensor system can effectively monitor strain and bending degrees, and judiciously detect body’s physical movements. By employing either frequency-based or amplitude-based sensing methods, the PSIW sensor system demonstrates versatility and adaptability for various strain sensing applications, highlighting its excellent potential for general use.

Keywords: Self-powered, Piezoelectric nanogenerator, Instantaneous wireless sensing, electronic switch, piezoelectric energy harvesting