Numerical and experimental studies of phase difference effects on flow rate of peristaltic micro-pumps with pumping chambers in series configurations

This paper studies phase difference effects on the flow rate of peristaltic micro-pumps using numerical and experimental approaches. In numerical simulation, commercial software (CFD-ACE+) is used. To focus on the phase relationship of peristaltic micro-pumps, all geometric parameters of the pump are fixed for a baseline design and the diaphragm motion is assumed as a sinusoidal waveform with a fixed frequency of 1 Hz. The phase difference between neighboring chambers is varied from 30°–120° in 10° increments. The pump configurations include the basic 3-chamber configuration and the configurations with up to 8 chambers in series arrangements. The computational results indicate that the maximum flow rate Q_max increases with increasing number of chambers (n). However, the maximum phase difference Δϕ_max for the maximum pump flow decreases with increasing number of chambers (n) in series pumps. The diaphragm oscillation amplitude also has a significant impact on the pumping flow rate. In the meantime, experiments are performed in an attempt to validate the computational findings. The pump diaphragm is fabricated using PDMS with iron particle contents, and permanent magnets are employed to actuate the diaphragm into movement. The phase relation between diaphragms are controlled by a set of rotary cams specially designed and fabricated for the experiments. Near rectangular waveform is used in the actuation of diaphragm movement. Results show that despite of the difference between computations and experiments, the basic trends of increasing Q_max and decreasing Δϕ_max with increasing number of chambers (n) are verified for peristaltic micropumps in series configurations.