Design and Fabrication of AlN Thick-Film Arc-Shaped Piezoelectric Energy Harvester

To achieve more efficient energy harvesting, an arc-shaped piezoelectric thick film energy harvester is proposed in this work, which is fabricated by depositing the 10 μm aluminum nitride (AlN) piezoelectric film on a stainless steel (SS) substrate using magnetron sputtering technique. Through theoretical analysis and simulation, the structural design and stress distribution in the arc-shaped piezoelectric thick film harvester are optimized, which enhances the electrical signal output of the sensitive unit, thus improves the output power. Additionally, the SS as a substrate not only enhances the adaptability of the device to environmental vibration, but also avoids complex and costly photolithography and etching processes. The AlN thick film deposited on the SS substrate exhibits good c-axis orientation and density. Under 1 g acceleration, corresponding to matching resistance of 125 kΩ, the arc-shaped piezoelectric energy harvester delivers a maximum VRMSoutput of 2.38 V at 355 Hz resonant frequency, yielding an output power of 45.3 μW. The optimization of piezoelectric thick film and structure paves a new path for high-performance piezoelectric energy harvesters.