Modelling and Analysis of Piezoelectric Cantilever for Ambient Kinetic Energy Harvesting

Wide bandwidth of vibration energy harvesters becomes one of most difficulties to their implementation but it is important to have cantilever beam that can tolerate wide variety of input frequency and able to harvest more kinetic energy. In this work, the piezoelectric material i.e. lead-zirconate-titanate (PZT), polyvinylidene fluoride (PVDF) and Aluminum Nitride (AlN) have been chosen to be analyzed. The piezoelectric cantilever beam structure, Unimorph type with dimension length of 40mm, 10mm width and thickness is 0.5mm has been proposed. The Finite Element Method (FEM) in ANSYS which consist of modal analysis, harmonic response analysis and statis structural analysis have been used to analyzed the characteristic of piezoelectric materials. Then, the full-bridge rectifier used to convert A-C to D-C sources using MATLAB Simulink and the experimental setup of the project was designed. The modal analysis result showed that PVDF material can applied greater maximum deformation than AlN and PZT material. The effect of dimension of cantilever beams of PVDF against natural frequency with different mode showed the natural frequency decrease when the dimensions of piezoelectric cantilever beam increase. On static structural analysis showed when the dimensions were increased, then the total deformation was decreased. Based on result of rectifying circuit for piezoelectric energy harvester using MATLAB Simulink, the positive and negative half cycle were conducted as theoretical studied. For the design verification, the experimental study showed the output voltage waveform is well regulated with minimum ripple.