High performance bimorph piezoelectric MEMS harvester via bulk PZT thick films on thin beryllium-bronze substrate

• Published in: Applied physics letters 2017-07, Vol.111 (1)
• Main Authors: Yi, Zhiran, Yang, Bin, Li, Guimiao, Liu, Jingquan, Chen, Xiang, Wang, Xiaolin, Yang, Chunsheng
• Format: Article
• Language: English
• Subjects: Acceleration; Amplitudes; Applied physics; Beryllium; Beryllium bronzes; Lead zirconate titanates; Light emitting diodes; Load matching; Load resistance; Microelectromechanical systems; Piezoelectricity; Stability analysis; Substrates; Thick films; Thin films; Tungsten
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4991368

This letter presents a high performance bimorph piezoelectric MEMS harvester with bulk PZT thick films on both sides of a flexible thin beryllium-bronze substrate via bonding and thinning technologies. The upper and lower PZT layers are thinned down to about 53 μm and 76 μm, respectively, and a commercial beryllium bronze with the thickness of about 50 μm is used as the substrate. The effective volume of this device is 30.6 mm3. The harvester with a tungsten proof mass generated the close-circuit peak-to-peak voltage of 53.1 V, the output power of 0.979 mW, and the power density of 31.99 mW/cm3 with the matching load resistance of 360 kΩ at the applied acceleration amplitude of 3.5 g and the applied frequency of 77.2 Hz. Meanwhile, in order to evaluate the stability, the device was measured continuously under applied acceleration amplitudes of 1.0 g and 3.5 g for one hour and demonstrated a good stability. Then, the harvester was utilized to light up LEDs and about twenty-one serial LEDs were lighted up at resonance under an applied acceleration amplitude of 3.0 g.