Low-temperature co-fired multilayer cantilevers based on relaxor-Pb(Zr,Ti) O3 for enhanced piezoelectric power generation at nonresonant frequency

Improving piezoelectric power-generation capability has been explored by modulating materials chemistry and device structure for specific low-power applications. Herein, high-performance multilayer cantilever structures based on perovskite 0.4Pb(Zn1/3Nb2/3)O3-0.6Pb(Zr0.5Ti0.5)O3 (0.4PZN-0.6PZT) with CuO additives are proposed as an example of electromechanical energy harvester utilizing nonresonant-frequency mechanical source. Even with low-temperature co-firing at 900 degrees C for 2 h to use inexpensive Ag inner electrodes, an optimized unimorph single-layer cantilever exhibited the best normalized power density of-10.8 mW cm-2 g- 2 Hz- 1 at 2 Hz with an acceleration of 0.028 g, which is far better than typical values reported for cantilever harvesters. The power value itself increased from-142.7 to-508.5 mu W with four layers while maintaining the high power density. The enhanced power with multilayers was attributed to the increased current due to extensive surface-charge polarization as the effective electrode coverage area was approximately quadrupled.