Net flow rate generation by a multi-pincher impedance pump

The impedance pump is a simple design that offers a promising technique for generating or augmenting net flow of macro or micro-scale devices without employing internal valves or blades. To obtain significant flow, large pinching amplitude or a wide pincher (actuator) is needed, leading to excessive stresses at high frequencies that may pose severe longevity issues. The present study is focused on the feasibility of increasing the net flow rate of an impedance pump using a sequential array of pinchers. This novel design is evaluated using numerical simulations based on a 1-D approximation that allows carrying out an extensive parametric study of the pump. It is shown that several pinchers working in resonance frequency and with the appropriate phase between them may result in a significant flow rate even when small pinching amplitudes or small-size pinchers are used. The net flow is generated by longitudinal standing wave patterns rather than a peristaltic action. The use of multiple pinchers allows controlling both the magnitude and direction of the net flow merely by changing the phase between them.