On the performance analysis of gas-actuated peristaltic micropumps

Abstract In this study, we report on the performance analysis of peristaltic micropumps to understand the impact of affecting parameters on micropump actuation membrane and overall micropump operation. To this end, a thermoplastic micropump consisting of three interconnected actuation units made of Poly(methyl methacrylate) (PMMA) and thermoplastic polyurethane (TPU) film is designed and fabricated. The actuation membrane for liquid pumping is made of TPU film that is located between the liquid and the actuation chambers. The effects of actuation gas pressure and actuation frequency on micropump characteristics in terms of pumping flow rate, volumetric efficiency, and generated liquid pressure are studied. A maximum flow rate of 56.28 ± 1.47 μl/min is obtained using an actuation pressure and frequency of 50 kPa and 15 Hz, respectively. An experimental setup is designed and assembled to measure the actual pressure experienced by the actuation membrane at different actuation frequencies and gas pressures. It is found that the increase of actuation pressure leads to the increment of membrane oscillation amplitude with subsequent increase of pumping flow rate and volumetric efficiency. However, a further increase of actuation pressure beyond a threshold (50 kPa) leads to the decline of membrane oscillation amplitude that decreases the flow rate. Also, an image processing of the actuation membrane reveals that the increase of actuation frequency results in the continuous reduction of the oscillation amplitude of micropump membrane. Similar to actuation pressure, the increase of actuation frequency beyond a critical value (15 Hz) leads to the decline of flow rate. Our findings provide critical insights required for optimal design and operation of micropumps and finding a compromise between optimum pumping flow rates and operating conditions for on-chip pumping.