Development of Hybrid GA-PSO for optimal design of valveless micropump in biomediacal application

Abstract

Micropumps are one of the most important components of microfluidic and microelectromechanical system (MEMS) because of the ability to transport fluids in microscale and have the control of the flow rate in an accurate and efficient manner. Various designs and approaches are suggested in order to develop a high performance micropump. This thesis presents the optimization method of valveless micropump utilizing the implementation of artificial intelligence (AI) approaches. The valveless micropump is designed with a diaphragm, pumping chamber and diffuser/nozzle elements functions as inlet and outlet with the outer dimension of 5 × 1.75 × 5 mm3. The implementation of structure optimization of valveless micropump is important in order to determine the maximum net flow rate that can be generated by the micropump with low power consumption. In order to determine the performance of the micropump, the total deformation, strain energy, equivalent stress, resonant frequency for diaphragm, fluid velocity and net flow rate of the micropump are investigated. Optimum back pressure for the diaphragm of valveless micropump was obtained through the result assessment. Optimization is done to maximize the total deformation, velocity, net flow rate and minimize the strain energy, equivalent stress and resonant frequency of the micropump. In order to evaluate the performance of the micropumps for medical application, a fitness function is constructed to evaluate the design variables of micropump structure. By executing optimization tools in conjunction with finite element analysis (FEA) software ANSYS workbench, the simulation and optimization model is able to find out the optimum micropump design parameters. The presented valveless micropumps are optimized in three deferent optimization methods which are genetic algorithm (GA), particle swarm optimization (PSO) and hybrid PSO with GA (denoted as HPSO-GA). Simulation results obtained are compared and investigated for the three optimization methods. From the research, simulation results show that the proposed HPSO-GA provide better solution for micropump performance. Results obtained through the developed model of HPSO-GA optimization stated that the maximum total deformation of the diaphragm is 8.4797 μm with 8 kPa actuation pressure and optimum net flow rate is 3.89 mL/min with velocity of 4.796 m/s.