In this paper the flow characteristic of laminar flow through planar diffuser was studied for different flow regime and its geometry, including angle, length and width were optimized. The diffuser shows flow recirculation and its efficiency is negative for diffuser angle larger than 30°. The analytical modelling of the micropump is solved by sectioning it as two separate units, an actuator unit and a flow unit. The actuator unit is a circular plate made of lead zirconate titanate (PZT) filler in polyvinyldene fluoride (PVDF) matrix composite material. The deflection of the actuator unit for bilaminar plate is analytically solved using theory of bending plates. The deflection profile of the actuator for the applied voltage is used to determine the stroke volume. The stroke volume from the actuator unit is used to solve the flow rate of the micropump analytically in the flow unit using mass balance equation. The flow rate of the micropump is numerically simulated in 3D for varying geometric and electrical parameters. The results obtained were compared and the numerical procedure was found to have less percentage error in the actuator deflection and flow rate up to a chamber depth of 250 µm. © 2020 Informa UK Limited, trading as Taylor & Francis Group.