Electrical Characterization of a Unimorph Vibration Energy Harvester with Al/AlN/Al Structure Realized by Magnetron Sputtering

In this work, the realization of a unimorph vibration energy harvester with an Al/AlN/Al structure by magnetron sputtering is proposed. Starting from an Al substrate, the device with an Al/AlN/Al structure was obtained by using a magnetron sputtering in two different operative conditions. The realized energy harvester was investigated in the unimorph bender set-up. The electrical characterization was performed by estimation of the AlN d31 piezoelectric coefficient and measurements of the output power. The estimated absolute value of d31 was 0.48 pC/N and the maximum output power was about 17 μW with 9.81 m/s2 (rms value) excitation acceleration.