DC-Voltage reduction for electrokinetic particle trapping in PDMS-based microfluidics

Abstract

The objective of this work is to reduce the voltage requirement for particle manipulation and trapping in an insulator-based microfluidic channel. Insulator-based microfluidic devices have been used in the past for particle analysis, separation, and concentration. Although some efforts have been successfully carried out to manipulate particles in microfluidic channels of this type, the electric fields required for particle movement and trapping are generally higher than 100 V cm-1, limiting the possibility of creating an integrated, portable device that is suitable for point-of-care applications. Starting with a two-post geometry for the insulating feature in our channel, we amplify the electric field at the center of the channel through dimensional optimization of the constriction and the post diameter, lowering the voltage required to be applied across the channel in order to achieve particle displacement and trapping. The present work includes the fabrication and experimental trapping results obtained in the channel designs produced after a modelling and optimization process to select the most efficient geometries to be created.