Biomicrofluidics. 2010 Jan 7;4(1):13201. doi: 10.1063/1.3279787.
Experiments show that particles smaller than the throat size of converging-diverging microchannels can sometimes be trapped near the throat. This critical phenomenon is associated with the negative dc dielectrophoresis arising from nonuniform electric fields in the microchannels. A finite-element model, accounting for the particle-fluid-electric field interactions, is employed to investigate the conditions for this dielectrophoretic (DEP) choking in a converging-diverging microchannel for the first time. It is shown quantitatively that the DEP choking occurs for high nonuniformity of electric fields, high ratio of particle size to throat size, and high ratio of particle's zeta potential to that of microchannel.
实验表明，有时比收敛-发散微通道喉口小的颗粒会被捕获在喉口附近。这种临界现象与微通道中不均匀电场引起的直流负介电泳有关。首次采用考虑颗粒-流体-电场相互作用的有限元模型，定量研究了收敛-发散微通道中这种介电泳（DEP）堵塞的条件。结果表明，DEP 堵塞发生在电场不均匀性高、颗粒尺寸与喉口尺寸比高、颗粒的 zeta 电位与微通道的 zeta 电位比高的情况下。
