Fabrication and drive test of pneumatic PDMS micro pump

This paper describes a pneumatically driven peristaltic PDMS micro pump toward harmless blood delivery system. Micro pump consists of three peristaltic-type actuators as dynamic valves and a micro channel connecting two chambers and two fluidic ports. Micro pump is fabricated through the PDMS mold process and the two-step curing process for irreversible bonding of PDMS layers. For the characterization of the pneumatic actuator, the deflection of actuator diaphragm is observed by using video camera. It is found out that the square-wave pneumatic input signal is preferable for the pneumatic action method to increase the volume stroke of the pneumatic PDMS actuators. Three types of the performance of micro pump in the frequency domain are performed while the square-wave input pneumatic pressure is applied to actuators. The maximum water suction volume speed from inlet port to micro pump is about 0.48 μL/s at 0.3 Hz under 7 cmH2O of the hydraulic pressure difference between two fluidic ports. The maximum meniscus speed of the red-ink in the micro channel is about 0.83 mm/s at 5 Hz. In the case of the injection test, the injected volume is approximately estimated with the recorded video clips showing the generated dynamic valve area of the actuator chamber region. It is about 75 nL at 1 Hz.