Abstract
A novel electrolysis-bubble-actuated micropump with a specific design on the hydrophobic surface of the lateral breather which could achieve a net pumping flow has been successfully developed. The micropump is implemented by means of electrolysis, surface tension effect and the periodic electrolysis-bubble generation. The advantages of this proposed micropump design not only achieve a net pumping flow but also resolve the main problem existing in most electrolytic bubble actuators for the issue of degassing the insoluble gases out of microchannels. This micropump with a simple circuit control and without moving parts is suitable for the development of low power-consumption and compact micropumps. Experimental results successfully demonstrate the pumping function of our micropump to continuously push liquid forward based on our gradient roughness design of hydrophobic surface and the periodic generation of an electrolytic bubble in a microchannel. Furthermore, experimental results also show that the liquid displacement and pumping rate could be easily and accurately controlled by adjusting the applied voltage with specific operating frequency. Under the applied voltage of 15 volts at 4.5 Hz, a maximum pumping rate of 114 nl/min is achieved for our micropump#1 with a microchannel cross section of 100 μm × 20 μm. In this paper, we describe the theoretical analysis, design, micromachining process, and operating principles, as well as the experimental demonstration of this micropump. Copyright © 2006 by ASME.