1. 제 목 : Stabilizing and Driving MEMS/Microfluidic Devices with


Surface Tension





2. 연 사 : Professor Chang-Jin “CJ” Kim


Mechanical and Aerospace Engineering Department


University of California, Los Angeles (UCLA)





3. 일 시 : 2001년 6월 20일 (수) 17:00 – 18:00





4. 장 소 : 301동 1512호





5. 내 용 : The research in the Micromanufacturing Laboratory at UCLA is geared to:


1) advance understanding of physical phenomena in microscale, 2) advance


and broaden micromachining technologies, and 3) develop new micromechanical


devices. A typical research project has all three aspects above intertwined with each


other. Effort is made to conceive the design ideas on the most fundamental level, so


that the devices being designed not only use the miniaturization technologies of


MEMS but also utilize (or avoid) the unique physics of being in microscale.


 


Some of the projects that utilize surface tension as a useful force for MEMS will be


presented. Droplet ejection mechanism using bubble check valve, pumping with


sequential bubbles in microchannel, electrostatic switching of liquid-metal droplet


demonstrate how surface tension attenuates liquid movement so effectively in


microscale. Moving droplets or bubbles under thermal gradient or electric potential


gradient demonstrates that surface tension can even pump liquids. Three different


types of electrowetting mechanisms are introduced: continuous electrowetting


(CEW), electrowetting (EW), and electrowetting on dielectrics (EWOD). The


efficiencies of these microactuation methods are unprecedented. CEW boasts low


voltage (only 1-2 V), low power (only ~10 mW), and high speed (100 mm/s). A CEW-


based liquid micromotor is demonstrated. EWOD covers much wider choices of


liquid but with higher driving voltage. Manipulation of droplets with EWOD and its


applications will be presented.





6. 문 의 : 기계항공공학부 고 상 근 교수 (☏ 880-7115)