A Study of Microbubble Generator and Its Applications

Generation of single microbubble by injection in microchannel has been investigated in this thesis. Microbubble generator is a cross type microchannel configured with contraction section. To analyze microbubble generation, two different contraction angles, 10° and 15° have been experimentally studied. Microchannels are fabricated in PDMS (polydimethysiloxane) by using soft lithography technique. Method of microbubble generation is to stop gas-liquid interface by contraction and segment gas stream into designed length by liquid from side channels. Stop position analysis shows that contraction channel stops the gas injection indeed. Further, by repeating the sequences of single microbubble generation in order to form microbubbly flow, and a model of microbubbly flow is developed preliminarily. Namely, a novel method for microbubbly flow formation is proposed in this thesis.