Bubble-based micropump for electrically conducting liquids

Abstract

This paper describes a novel pumping device without mechanical moving parts based on the periodic generation and collapse of a single vapour bubble in a channel. The channel shape is such that it creates an asymmetry in the surface tension forces, which results in a pumping effect. The principle can be implemented over a broad range of channel sizes and repetition frequencies. For illustration purposes, a particular implementation is described here where the working fluid is a salt solution in water, the channel diameters are of the order of 1 mm and the repetition frequency is between 1-10 Hz. In these conditions, the device develops a head of a few centimetres of water with typical flow rates in the range of 100 l per minute. It appears possible to increase both head and flow rate by adjusting geometrical parameters and operating conditions. A simple modification of the design would render the same principle also applicable to the pumping of non-conducting liquids.