Continuous and Regulated Organic Micro Bubble Generation Using Lumped Gas and Organic Injected Junction Takahiro Yamamoto, Takahiro Arakawa and Shuichi Shoji. Major in Nano-science and Nano-engineering, Waseda University 3-4-1, Ohkubo, Shinjuku, Tokyo, 169-8555, Japan MEMS Conference 2007 Advisor：Prof. Cheng-Hsien Liu Reporter：Chao-Ming Chang Date：2007.6.6

Outline Introduction Design and Fabrication Experimental Setup Result and Discussion Conclusion

Coaxial Microcapillary Fluidic Device Introduction Coaxial Microcapillary Fluidic Device “Monodisperse Double Emulsions Generated from a Microcapillary Device” Ref. A. S. Utada. et. al. 2005.

T-Shaped Microchannel Cross-Shaped Microchannel Introduction T-Shaped Microchannel “RAPID PREPARATION OF MONODISPERSED DROPLETS WlTH CONFLUENT LAMINAR FLOWS” Ref. Takasi Nisisako et. al. 2003 Cross-Shaped Microchannel Ref. Liqing Ren. et. al. 2003.

Schematic view of the micro bubble generation system Design and Fabrication Schematic view of the micro bubble generation system

CONCEPT Concept of the micro bubble generation Design and Fabrication （Butyl Acetate）醋酸丁酯 （Air） （3% Polyviny Alcohol）聚乙烯醇 Concept of the micro bubble generation

Design and Fabrication Fabrication Process Pad Fabrication process of the device

Design and Fabrication Fabrication Result 製程結果的SEM圖，這樣的製程看起來不會太複雜。 SEM image of the fabricated Si microchannel at the junction

Schematic of the experimental setup

High-speed CCD image of the micro bubble generation Result and Discussion High-speed CCD image of the micro bubble generation

Experimental results Limited Result and Discussion Experimental results Limited Image of the micro bubble at observation area (Organic phase flow rate(Qo)： 2, 1, 0.5 uL/min, Gas：4uL/min, Water：8uL/min)

Water phase V.S. Bubble diameter Result and Discussion Water phase V.S. Bubble diameter Bubble diameter V.S. water phase flow rate

Bubble pitch V.S. Water phase Result and Discussion Bubble pitch V.S. Water phase Bubble pitch and generation rate V.S. water phase flow rate

Conclusion The diameter of micro bubble, and generation rate were controlled by water phase flow. The average bubble pitch increased, when water phase flow rate increased. The organic membrane became thinner when organic phase flow rate decreased. The organic membrane is expected to be used as a media for high efficiency reaction.

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