1. UKM Learning and Research Repository
2. PHD Thesis / Tesis PHD
3. Institute of Microengineering and Nanoelectronics / Institut Kejuruteraan Mikro dan Nanoelektronik (IMEN)

Title:	Modeling of an integrated vibration and fluid flow piezoelectric micro cantilever for energy harvesting
Authors:	Mohammad Shaharia Bhuyan (P57788)
Supervisor:	Md. Shabiul Islam, Prof. Madya Dr.
Keywords:	Energy harvester Fluid flow Vibration
Issue Date:	15-Jan-2015
Description:	An energy harvester device captures and stores minute amounts of energy from ambient environment such as solar, wind, vibration and kinetic energy to charge or replace batteries in micro-electronics system, where battery use is inconvenient, impractical, or expensive. The key challenge for successful deployment of energy harvester technology still remains in the provision of adequate energy. This thesis aims to address this challenge by investigating on a Finite Element Analysis (FEA) energy harvesting device model to enhance the output power in μW levels of a fluid flow induced vibration based piezoelectric energy harvester. Firstly, a simplified analytical model of a unimorph piezoelectric micro cantilever capable of transforming low level vibrations into electricity has been developed based on Euler-Bernoulli method. Later, the micro cantilever model utilized Matlab based Genetic Algorithm (GA) optimization routine to find the optimum geometric parameters. The optimized micro cantilever produced 1.3 μW at resonant frequency of 24 Hz. The mechanical parameters of the optimized unimorph piezoelectric micro cantilever have been validated by FEA in COMSOL Multiphysics software. The FEA model of the micro cantilever provides the same mechanical parameters of the piezoelectric cantilever at the natural frequency of approximately 24.43 Hz, stress of 22.98 MPa and tip displacement of approximately 7.44 mm. Based on Reynolds number analysis of few bluff-body shapes, a D-shaped bluff body has been chosen to be integrated with the optimized micro cantilever. After the integration of the optimized micro cantilever with the D-shaped bluff-body the whole structure has been assembled inside a three-dimensional micro channel to develop the complete fluid flow based energy harvester in COMSOL Multiphysics. Low velocity fluid flow has been modelled in COMSOL to create 'Kármán Vortex Street' in the wake of the bluff body. The complete 3D fluid flow based energy harvester FEA model has been investigated in low fluid-flow velocities ranging 1-5 meter/second in terms of harvested electrical potential. The (200×150×150) μm3 FEA model of the energy harvester produced 2.9 mV at 1.5 m/s flow velocity. The novelty of the design relies on integrating the optimized micro cantilever with the D-shaped bluff body that implies piezoelectric micro cantilever as a direct vortex shedding energy harvester instead of using parasitic vibration. The harvested energy can be utilized for low duty cycle sensors application that requires average power of 1-20 μW. This research aid some way towards closing the existing gap between energy requirements of microelectronic devices and the amount of energy that can be harvested by a piezoelectric energy harvester from the low velocity fluid flow.,Ph.D.
Pages:	94
Publisher:	UKM, Bangi
Appears in Collections:	Institute of Microengineering and Nanoelectronics / Institut Kejuruteraan Mikro dan Nanoelektronik (IMEN)

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.