Optimization of design and characterization of a novel micro-pumping system with peristaltic motion

Abstract

In this work, we present a novel design of peristalsis based micro pump with optimized fluid chambers possessing improved discharge efficiency per unit volume of the pumping architecture and reduced reverse flow. Such designs are very often important from the standpoint of blood cell sorting assays where a full delivery of fluid containment within the pumping chamber is critical. The paper uses FLUENT and COMSOL simulations to look at the fluid flow within the pumping chamber due to the deflecting actuator membrane during pumping cycle. The resulting effect of fluid-membrane interaction has been evaluated on different chamber designs for observing the lateral velocity distribution profile of fluid in the connecting channels. It has been observed through particle image velocimetry (PIV) that the optimized design has minimized chamber retainability with maximum deflection of the actuator membrane and minimum reverse flow component. Optimized geometrical profile formulated above was seen to allow the maximum contact area between actuating membrane and fluid containment thus reducing the problem of fluid retainability. Other experimental studies show that the new design has much lower percentage retainability of biological and other fluids contained within the chambers which makes it a comparatively high efficiency micropumping system with respect to the conventional design with circular membrane and chambers. The experimental evaluation of the new micro pump design has shown its least count to be 0.1 μl/min which is very well comparing with some of the other micropumping mechanisms like electro-osmotic, magneto-hydrodynamic mechanisms (Laser and Santiago in J Micromech Microeng 14:35, 2004; Iverson et al. 2008) and additionally provides better discharge efficiency per unit volume of the pumping architecture, lower retainability, minimized reverse flow and precise pumping of fluids.