Fabrication of a peristaltic micro pump with novel cascaded actuators

Abstract

This paper presents the fabrication of an all-PDMS (polydimethylsiloxane) micro pump with novel cascaded actuators as dynamic valves. The micro pump consists of three pneumatic actuators in series and a micro fluidic channel connecting two fluidic inlet and outlet ports. The three-layer bonded pump structure is fabricated through a typical moulding process of PDMS and a simple heating process for the PDMS-to-PDMS bonding. The total size of the micro pump is 5 mm × 5 mm. The dynamic valve pattern of the single actuator is observed under various operational conditions of the square-wave input signal for the estimation of its volume stroke. The maximum volume stroke of the pneumatic actuator for liquid is about 85% of the volume of the liquid chamber. Three types of liquid-pumping tests are performed for characterization of the micro pump such as backpressure, frequency and viscous liquids. The flow rate of the de-ionized (DI) water is about 73.9 nl min−1 at zero backpressure. As the hydraulic difference between inlet and outlet ports increases, the flow rate gradually decreases. In the case of the frequency responses, the micro pump has the maximum flow rate of the DI water at 2 Hz. The viscosity-dependent flow rate of the working fluids is also observed.