[기계] Magnetohydrodynamic and Electrophoretic Flows for Lab-on-a-Chip Applications

1. 제 목 : Magnetohydrodynamic and Electrophoretic Flows for Lab-on-a-Chip Applications

2. 연 사 : Shizhi Qian(Department of Aerospace Engineering, Old Dominion University)

3. 일 시 : 2009년 5월 20일(수) 16:00~17:00

4. 장 소 : 301동 1512호

5. 내 용 :
A lab-on-a-chip (LOC) is a minute chemical processing plant with interconnected networks of micro- or nanochannels and reservoirs operating with small volumes of reagents. In many LOC applications, it is necessary to propel fluids from one part of the device to another, control fluid motion, and stir and interact various reagents, which are nontrivial tasks in a very small scale.
The first half of this talk will describe magnetohydrodynamics (MHD)-based icrofluidics. MHD-based micropumps, networks and chaotic stirrers, in which the flow is directed by judicious interplay between electric and magnetic fields, have been designed, modeled, constructed, and tested. The MHD networks allow one to move reagents along any desired path, stir liquids, and facilitate chemical and biological interactions without the use of any mechanical pumps, valves or moving parts. Applications for Polymerase Chain Reaction (PCR), mercury detection, and preparation of radioactive sources will also be demonstrated.
The other half of this talk will be on the transient electrophoretic motion of a charged particle in microfluidic devices with complex geometries giving rise to spatially non-uniform electric fields. The fluid-particle system is studied by solving the coupled system of the Navier-Stokes equations for fluid flow and the Laplace equation for electrical field with an arbitrary Lagrangian-Eulerian finite-element method. In addition to the electrostatic and hydrodynamic forces, the particles experience direct-current (DC) dielectrophoretic (DEP) forces arising from the interaction between the dielectric
particles and the induced spatially non-uniform electric field. The effect of the induced DC-DEP force on the particle motion is investigated as functions of the particle size, the electric field intensity, and the zeta potential of the particles and of the channel wall. The predicted particle trajectory is in good agreement with existing experimental data. The induced DEP force must be taken into account for the electrophoretic motion of particles in microfluidic devices containing spatially non-uniform electric fields.

6. 연사경력 :
- Dec. 2004 Ph.D. in Mechanical Engineering and Applied Mechanics, Univ. Pennsylvania
- Aug. 2005 - Jun. 2008 Assistant Professor, Dept. Mechanical Engineering, Univ. Nevada Las Vegas
- Jul. 2008 - Present Assistant Professor, Dept. Aerospace Engineering, Old Dominion Univ., Norfolk, VA, USA

7. 문 의 : 기계항공공학부 김호영 교수(☏ 880-9286)