Energy harvesting performance of unimorph piezoelectric cantilever generator using interdigitated electrode lead zirconate titanate laminate

Abstract An unimorph piezoelectric cantilever generator with an interdigitated electrode (IDE) was developed for application to vibration energy harvesters driven in longitudinal mode. Lead zirconate titanate (PZT) thick film was fabricated by lamination of 10 sheets printed with Ag IDE; the laminated film was subsequently cofired at 850 °C for 2 h. Compared with a conventional IDE PZT thick film, the approximately 270 ㎛-thick cofired IDE PZT laminate revealed a significantly increased capacitance due to reduction of transition area. The use of multilayered IDE could result in the enhancement of energy harvesting performance for unimorph piezoelectric cantilever generator using PZT laminate. Optimized bending resonance frequency was obtained at 78 Hz for the unimorph piezoelectric cantilever generator with tip mass of 2.3 g driven in longitudinal vibration mode. Its energy harvesting performance was characterized as having a high power density of 26.7 mW/cm 3 across the resistive load of 80 kΩ, corresponding to a normalized power factor of 6.7 mW/G 2 ·cm 3 .