Design Simulations of a Micropump with Multiple Actuating Mechanisms
K. Koombua, R.M. Pidaparti
Virginia Commonwealth University, US
Keywords: valveless micropump, nozzle/diffuser element, microfluidic simulation, PDMS micropump
Abstract:This paper presented the design simulations of a valveless micropump with novel multiple vibrating membranes as actuators and investigated its performance characteristics. The designed PDMS micropump consists of three nozzle/diffuser elements with vibrating membranes that are used to create pressure difference in the pump chamber. Pump chamber has an hourglass shape and is made of PDMS polymer. An actuator unit is made of piezoelectric material. Change in length and curvature of the piezoelectric material results in decrease or increase in a volume of the pump chamber. Two actuating mechanisms were chosen: sidewall- and topwall-actuating mechanisms. The performance characteristics of the designed micropump were analyzed using ANSYS and ANSYS CFX, the solver based on the finite element and finite volume method, respectively. The fluid-structure interaction (FSI) algorithm was employed to study transient responses of fluid velocity, pressure distribution, and flow rate during the operating cycle. The simulation results showed that the movement of membranes combined with the rectification behavior of three nozzle/diffuser elements can minimize back flow and improve net flow in one direction. Based on the performance characteristics from the simulations, the designed micropump is feasible and suitable to fabricate for practical applications.