A collapsing bubble-induced micropump: An experimental study

It is well known that a jet develops in a (non-equilibrium) oscillating bubble near a solid wall. The jet is directed towards the wall and is usually of very high speed (∼100 m/s). Some experiments with a pump based on this principle using a bubble near a plate with a small hole in it are presented. The basic principle of this pump with no moving parts was illustrated numerically in a previous work, but without any experimental data for verification. The hole in the wall is made at the location where the jet would have impacted and thus transport liquid from one side of the plate to the other side. Various experimental results with different conditions are shown. The distance between the bubble and the wall and the diameter of the hole in the wall are the main varying parameters. Our findings indicate the effectiveness of the pumping action for a wide range of flow conditions and parameters. A distinct advantage of this collapsing bubble-induced micropump is that there are no moving parts and the response time of the pump is very fast (milliseconds or below).