Enhancement of Mixing by Microbubble Emission Boiling in a Microfluidic Device

Article type: Research Article

Authors: Kato, H. | Yamaguchi, M.

Affiliations: Department of Mechanical Engineering, Toyo University, Kujirai, 2100, Kawagoe, 350-8585, Japan | Graduate School of Engineering, Toyo University, Presently Ageo East Junior High School, Japan

Abstract: The effect of microbubble emission boiling (MEB) on the mixing of two fluids in a microfluidic device was studied experimentally. When MEB occurred on an electric heater made of a platinum wire with a diameter of 30 micrometers, the mixing of the two fluids increased markedly. However, nucleate boiling had no significant effect on the mixing. A high-speed video showed that the very rapid growth and collapse of micro boiling bubbles on the heater causes the strong mixing of the two fluids. The coexistence of highly superheated and highly subcooled water near the heater seems to be the reason for such enhanced mixing.

Keywords: Microfluidic device, μ-TAS, Microbubble emission boiling, Mixing, Enhance

Journal: Journal of Visualization, vol. 12, no. 3, pp. 267-274, 2009