Analysis of material properties for thin film membrane in thermal actuated micropump

This paper presents a comparison of thin film materials used as movable membrane for thermal actuated micropump. The materials discussed are PMMA, polyimide, silicon nitride (Si₃N₄) and single crystal silicon. The properties of membrane material are characterized using Finite Element Analysis (FEA) to study its mechanical and physical behavior that are suitable to be used as an actuator for thermal micropump. Parameters such as density, elastic modulus, stiffness, Poisson ratio, size, dimension and thickness are studied to find the optimum design for the membrane. From the analysis, it was shown that polyimide has the highest deflection that ranges from 0.13-0.86 μm at dimension area of less than 12 mm². Polyimide is also the most promising candidate material for the pump membrane due to its elasticity, robustness, simple fabrication and its capability to handle very high temperatures.