Simultaneous Wireless Strain Sensing and Energy Harvesting From Multiple Piezo-Patches for Structural Health Monitoring Applications

Abstract

This paper presents a novel approach called simultaneous wireless strain sensing and energy harvesting from multiple piezo-patches, which is intended for self-powered structural health monitoring (SHM) applications. The energy harvesting (EH) subsystem is mainly the self-powered extended synchronous electric charge extraction interface based on double cross-coupled rectifying structure and a single flyback transformer, which is able to harvest energy from multiple piezo-patches. Also, the wireless strain sensing (WSS) subsystem is mainly the low-power multiplexing analog front end, which is designed to process the multichannel strain signals. The innovation of the proposed approach is that energy harvesting and strain sensing can actually work simultaneously without interfering with each other. The prototype is implemented based on discrete components and tested with an emulated SHM system. Experimental results show the EH subsystem can produce 5.45 mJ energy in 100 s under 108 με and 30.4 Hz dynamic strain. The average current consumption of the WSS subsystem is 7.53 μA, and the required energy in a 100 s is 2.49 mJ, which means the system is able to self-start even if the battery is exhausted. Additionally, the self-powered capacity can be further improved in a practical SHM system since more piezo-patches can be employed.