< BK21 플러스 BEST 정보기술 사업단 세미나 개최 안내 >

개최일시 : 2016년 06월 23일 목요일 10:30 ~ 11:30

개최장소 : 제 2공학관 B701호

세미나 제목 : Microfluidics: the Leidenfrost effect and the elasto-inertial particle focusing

발표초록 :

This talk will cover two topics: one is the Leidenfrost effect and the other is the elasto-inertial particle focusing in a microfluidic platform. Firstly, The liquid drop can bounce off after impact on the surfaces when it overcomes gravitational and adhesion forces. Here, we report an anomalous liquid drop bouncing phenomenon that is generated by the Leidenfrost levitation due to the vapor layer reducing energy dissipation during the collision. The Leidenfrost levitation of water drops on both a hydrophobic surface and nanotextured Cassie surface is investigated. When the water drop is positioned onto the heated nanostructure surface, a superhydrophobic feature is observed by the levitation effect due to the vapor film. The nanostructure results in a slow evaporation of the drop due to the low thermal conductivity of the vapor layer that inhibits heat transfer between the heated surface and the water drop. Secondly, different size particles are separated by employing a facile two step label free particle separation technique which consists of elasto-inertial particle focusing and magnetophoretic particle migration. The elasto-inertial force leads the particles to move toward the centerline at the first stage, followed by particle size-dependent lateral migration due to the magnetophoretic force at the second stage of the microchannel. An analytical calculation is carried out to predict the trajectories of different size particles by considering hydrodynamic viscous drag and magnetophoretic repulsion forces, and compared with the experimental results. Numerical analyses are performed to understand the physics underlying the elasto-inertial particle focusing and the magnetophoretic particle migration.

강연자 : 송영석 교수 / 단국대 파이버시스템공학과

초청자 : 전기전자공학과 교수 이태윤