Impedance pump explained

An impedance pump is a valveless pump consisting of an elastic tube connected on both ends to an inelastic tube. Tapping the end of a tube will cause flow of liquid inside the system.

Very small versions of an impedance pump -- a micro impedance pump -- can be used as a micropump for lab-on-a-chip active microfluidics.^[1]

Notes and References

1. Rinderknecht, Derek Gresham (2008)."Development of a microimpedance pump for pulsatile flow transport : Part 1: Flow characteristics of the microimpedance pump. Part 2: A systematic study of steady and pulsatile transport in microscale cavities.".Dissertation (Ph.D.), California Institute of Technology.http://resolver.caltech.edu/CaltechETD:etd-05292008-115810

   https://thesis.library.caltech.edu/5215/.says:"The micro impedance pump is valveless, bidirectional, and can be constructed simply from a wide range of materials."."The Impedance Pump".p. 29 says"... impedance pumps in a planar format which can easily be prototyped with other microfluidic components within the context of Lab on Chip diagnostics."