A Hybrid Piezoelectric and Electrostatic Vibration Energy Harvester
Micro Electro Mechanical Systems for vibration energy harvesting have become popular over recent years. At these small length scales electrostatic forces become significant, and this paper proposes a hybrid cantilever beam harvester with piezoelectric and electrostatic transducers for narrow band base excitation. One approach would be to just combine the output from the different transducers; however, this would require accurate tuning of the mechanical system to the excitation frequency to ensure the beam is resonant. In contrast, this paper uses the applied DC voltage to the electrostatic electrodes as a control parameter to change the resonant frequency of the harvester to ensure resonance as the excitation frequency varies. The electrostatic forces are highly non-linear, leading to multiple solutions and jump phenomena. Hence, this paper analyses the non-linear response and proposes control solutions to ensure the response remains on the higher amplitude solution. The approach is demonstrated by simulating the response of a typical device using Euler Bernoulli beam theory and a Galerkin solution procedure.
KeywordsMEMS Energy harvesting Electrostatic forces Nonlinear
Hadi Madinei acknowledges the financial support from the Swansea University through the award of the Zienkiewicz scholarship.
- 15.Madinei, H., Haddad Khodaparast, H., Adhikari, S., Friswell, M.I., Fazeli, M.: Adaptive tuned piezoelectric MEMS vibration energy harvester using an electrostatic device. Eur. Phys. J. Special Topics. 224(14), 2703–2717 (2015)Google Scholar