Modular architecture in micropump

Abstract

This research addresses the design of modular setup of micropump wherein the two basic components of micropump: actuation and flow rectification element are separated. Conventional approach with integrated actuator within the micropump shows less flexibility and discourages disposable usage. Furthermore, fabrication methods of these components need to be compromised to achieve pumping target. Hence, this research investigates and studies the flow behaviour of the modular micropump with a diffuser and a gourd-shape channel design in the flow rectification module. Numerical simulations were built in COMSOL Multiphysics to study and optimise parameters in module design. Based on the obtained parameters from the simulation results, the diffuser module was fabricated on poly (methylmethacrylate) (PMMA) polymer using a rapid hot embossing replication method, whereas the gourd-shape module was fabricated on poly (dimethylsiloxane) (PDMS) polymer with a photolithography and a replication moulding (REM) technique. The actuating gaps between the actuation module and the flow rectification module were studied. The diffuser module (100 µm membrane thickness) exhibited largest flow rate range of 0.06–5.78 mL/min with back pressure 1.35 kPa at 2.5 mm gap. The flow rate performance increased 16.43% with a thinner membrane, 70 µm. For multifunctional application, the gourd-shape chamber module poses bi-directional pumping and mixing characteristic. Experimental result shows the micropump with the flow rate range of 0.20–1.52 mL/min (forward direction) and 0.05–1.48 mL/min (reverse direction). The attributes of the mixing when using this module was further investigated in a forward flow configuration. The mixing performance was quantified by digitally counting each gray level of the captured image. Exclusively, the experimental findings of the proposed modular micropump indicate that the modular architecture is well adapted in micropump development with the advantageous of large flow rate range, flexible with multi-functionality and disposable features.