Design and Analysis of a T-shaped Piezoelectric Cantilever Beam at Low Resonant Frequency using Vibration for Biomedical Device

摘要

Background: Ambient vibration energy can be converted into electrical energy in an energy harvester system by using three mechanisms; piezoelectric, electrostatic and electromagnetic. Among three mechanisms, piezoelectric mechanism is most efficient. In this mechanism, mechanical stress and strain generation of piezoelectric materials can be converted into electrical energy by ambient vibration energy for low power electronic system. To implement a piezoelectric energy harvester system from ambient vibration, a lower range of frequency will be chosen. To achieve the lower resonant frequency and higher stress of energy harvester, a cantilever beam is suitable because of its least stiff structure. Materials and Methods: The structural properties of a T-shape piezoelectric cantilever beam was analysed for piezoelectric energy harvesting mechanism. The 3-D geometry of the beam has been design using solid works. After that the simulation of the T-shaped piezoelectric cantilever beam has been performed by using Finite Element Analysis (FEA) in COMSOL multiphysics. In FEA simulation, the volume of the beam was considered 24.566×10^?3 cm³ under a vibration source of 0.5 g acceleration. Results: As a result, the beam was resonated at a frequency of 229.25 Hz. During resonance, free end of the beam has displaced the maximum 2.77 mm with RMS velocity of 3.29 m sec^?1. Finally, maximum stress of 2.39×10⁸ N m^?2 has found near the fixed end of the beam. Conclusion: This designed and analysed T-shaped piezoelectric cantilever beam will be suitable for scavenging and converting ambient low vibration energy into electrical energy for biomedical devices. The shape of the cantilever beam was designed as T-shape. In the design, complexity of the beam was reduced and no proof mass was used at the free end of the beam. After the analysis of the beam, a lower resonant frequency of 229.25 Hz was achieved compared to past researchers studies.