报告题目：Electrokinetic Manipulation of Particles and Cells in Microfluidic Devices
报告时间：2022.8.17 09:30 - 11:00: Wall effects on particle electrophoresis in straight microchannels.
宣向春教授任职于克莱姆森大学机械工程学院。于2006年获得多伦多大学机械与工业工程系博士学位，于1995年获得中国科学技术大学工程学士学位。2012年，宣向春教授获得NSF Career Award，并于2022年获得克莱姆森大学杰出博士导师奖。他的研究领域涉及微流控基本原理和应用，主要聚焦于粒子和细胞操纵机制研究。
Microfluidic devices have been increasingly used over the past two decades for numerous chemical, biomedical and environmental applications. A precise transport and placement (e.g., focusing, trapping, separation, etc.) of particles and cells in microchannels is often involved in these devices. Among the various particle and cell handling approaches (e.g., optical, acoustic, magnetic, inertial, etc.), electric field is the method of choice for microfluidic systems because of the ease, precision, and autonomy of operation and integration with pre- and/or post-analysis parts. It controls the motion of particles and cells by fluid electroosmosis and particle electrophoresis, both of which are proportional (in magnitude) and parallel (in direction) to the imposed electric field. Such linear electrokinetic phenomena can thus transport particles and cells along the channel length direction only. I will present in this three-talk series our recent projects on the exploration and utilization of nonlinear electrokinetic phenomena for continuous-flow particle and cell manipulation. Specifically, I will cover two types of particle motions that each vary nonlinearly with the applied electric field and have a tunable angle to the electric field direction for additional degrees of freedom. In the first two talks, I will report how the presence of microchannel walls affects the electrophoretic particle velocity and induces a dielectrophoresis-like particle migration (Talk 1), as well as the use of the latter to focus and separate particles and cells in straight uniform microchannels (Talk 2). In the last talk, I will report the use of channel structure to create electric field gradients for dielectrophoretic manipulation of particles of cells (Talk 3).