Experiments on a wireless power transfer system for wearable device with sol-gel thin-film PZT

This paper presents experiments on a low-frequency wireless power transfer system (WPTS) using a piezoelectric transducer with a magnet tip mass as a receiver. The thin-film piezoelectric bimorph cantilever is fabricated by sol-gel processing with the aim to miniaturize the system for wearable applications. The device couples an applied electromagnetic field to the mechanical transverse vibration of the beam, which then induces a voltage across a load resistance connected to the electrical ports. This coupled mechanism is therefore referred to as the magneto-mechano-electric (MME) effect. A power of 3.4 μW is generated in a resistance of 200 kΩ at a magnetic flux density of 100.3 μT. The potential of utilizing the same piezoelectric resonator for both energy harvesting and wireless power transmission modes is shown.