Microfluidic Chip for Separation and Manipulation of Cells and Microparticles

Abstract

Medium exchange is the process of changing the suspension medium of cells/particles and has applications in washing, surface modifications, nutrient replenishment, or simply changing the environment of the target entities. Dipping involves diverting the path of target cells in the carrying fluid to immerse them in another fluid for a specific duration and pushing them back into the original medium. This work presents an analytical formulation for the Dielectrophoretic force within a microchannel. A set of electrodes protrude slightly into the channel from a sidewall at the bottom of the channel. The electric field distribution and the resulting Dielectrophoretic force in the channel is calculated analytically by solving the governing equations along with the boundary conditions. The same results are obtained numerically and an excellent agreement is found. Moreover, numerous finite-element-based parametric studies are carried out to obtain the optimized geometrical and operational parameters ensuring successful dipping and medium exchange processes. The results of those studies are utilized to fabricate the platform using standard photolithography techniques. The electrodes are patterned on a glass substrate while the channel, made out of polydimethylsiloxane, is bonded on top of the glass. Trajectories of blood cells from numerical studies and experimentations are reported and both results exhibited close agreement.

Date of Award	Mar 2019
Original language	American English