Energy Harvesting and Power-Management for Sensing Skins in SHM Applications

Abstract

Self-powered operation can substantially ease the deployment and adoption of SHM systems. In this work, thin-film power-management systems are presented, which achieve energy harvesting and wireless power delivery to sensing subsystems all using the same thin-film amorphous-silicon (a-Si) technology. This enables a future path to systems with low assembly complexity. Two thin-film inverter topologies for wireless power delivery are discussed: (1) a class-D switching power inverter; and (2) an LC-oscillator-based power inverter. Among these, the class-D power inverter achieves wireless power delivery of 120 μW at an efficiency of 22%, while LCoscillator- based power inverter achieves wireless power delivery of 22 mW at an efficiency of 31%. Though the power levels are adequate for some SHM systems being envisioned, the superior power level of the LC oscillator makes it relevant for a wide range of systems.