Session Track
November 01 (Wednesday)
바이오공학부문 포스터
Poster,
3층 로비,
15:50~16:40
- 신현정(KAIST), 조영삼(원광대), 김성진(건국대), 양성욱(KIST)
We16D-2
15:50~16:40
표면의 화학 특성에 따른 젖음성 변환의 제어 차원
Applications such as lab-on-chip technology and self-cleaning technology needs tuning of the wetting transitions by controlling simple physicochemical characteristics of the surfaces. In this work, we demonstrate our ability to tune the dimensionality of wetting transitions by appropriate choice of surface energy. We used butterfly-wing inspired micro-cavity surfaces with varying longitudinal to lateral length ratio of the cavities to alter the local fluid-structure interaction giving rise to varied wetting phenomenon. Three different surfaces having equal enclosed area and different perimeters were fabricated. Surface chemistry was altered using 20 nm thick coatings of diamond-like carbon (DLC), Fluorinated diamond-like carbon (FDLC) and polytetrafluoroethylene (PTFE). Wetting studies were performed using sessile drop and evaporation methods with drop sizes varying from 0.25 µl to 5 µl. We show that on our cavity surfaces, nucleation scenarios for the Cassie to Wenzel transition can be varied from 2-D to 1-D by altering interplay between surface geometry, drop geometry, and surface chemistry. Importantly, we show that FDLC coated micro-cavity surfaces exhibited 1-D wetting transition due to the pressure and velocity gradients resulting from the internal flow of the drop during the ‘rush hour’ period of the drop life. Our results prove that internal flow dynamics can be used to alter transition dynamics of wetting states at an appropriate surface energy.
Keywords : Wetting transition(젖음성 전환), drop dynamics (물방울동역학), Evaporation(증발)
Paper : We16D-2.pdf
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