Quasi-static motion of bubbles in microchannel contractions

Mads Jakob Jensen, Goran Goranovic, and Henrik Bruus
Mikroelektronik Centret, bldg. 345 east, DK

Keywords: bubble dynamics, microchannels, contraction, surface tension, contact angle

Abstract:
We present a thorough theoretical and computational study of bubble dynamics in icrofluidic channels with contractions. We investigate the effects of geometry and surface physics (friction and contact angle) on the behavior of incompressible bubbles, and we propose a set of design rules to minimize the clogging of channel contractions by bubbles. Based on the interplay between surface tension, geometry, and contact angle, we analyze theoretically the difference between bubble motion in a tapered and a sudden contracting microchannel. Our results show how the energy gradient of, i.e. the force on, a bubble is lower in a tapered contraction compared to a sudden contraction. The analysis is thus a powerful tool to optimize microfluidic networks with respect to minimize clogging of microfluidic channels by gas bubbles.

NSTI Nanotech 2003 Conference Technical Program Abstract