Fabrication of High-Efficiency Piezoelectric Energy Harvesters of Epitaxial Pb(Zr,Ti)O ₃ Thin Films by Laser Lift-off

Abstract

Abstract We fabricated piezoelectric vibration energy harvesters of c -axis-oriented epitaxial Pb(Zr,Ti)O 3 (PZT) thin films on stainless steel (SS304) cantilevers in an effort to improve their power-generation efficiency and toughness. Using radio-frequency magnetron sputtering, we deposited the epitaxial PZT thin films on the MgO substrates, and then transferred the PZT films onto microfabricated SS304 cantilevers using laser lift-off (LLO). LLO did not degrade the transferred epitaxial PZT thin films, which exhibited a high piezoelectric coefficient ( e 31, f =–4.8 C/m 2 ) and a low relative dielectric constant ( ε r =340), comparable to those of the original PZT thin film on MgO. At a resonance frequency of 143 Hz, the energy harvesters generated large output power of 1.8 μW at an acceleration of 1.0 m/s 2 , and the output power reached a maximum of 49 μW at an acceleration of 7.5 m/s 2 .