Electrokinetic Propulsion of Polymer Microparticulates Along Glassy Carbon Electrode Array

Abstract

Dielectrophoresis (DEP) is a force applied to microparticles in nonuniform electric field. This study discusses the fabrication of the glassy carbon interdigitated microelectrode arrays using lithography process based on lithographic patterning and subsequent pyrolysis of negative SU-8 photoresist. Resulting high-resistance electrodes would have the regions of high electric field at the ends of microarray as demonstrated by simulation. The study demonstrates that combining the alternating current (AC) applied bias with the direct current (DC) offset allows the user to separate subpopulations of microparticulates and control the propulsion of microparticles to the high field areas such as the ends of the electrode array. The direction of the movement of the particles can be switched by changing the offset. The demonstrated novel integrated DEP separation and propulsion can be applied to various fields including in vitro diagnostics as well as to microassembly technologies.

Guided Electrokinetic Assembly of Polystyrene Microbeads onto Photopatterned Carbon Electrode Arrays

“…Guided electrokinetic assembly techniques operate on the proper scale for the assembly of microparts and implement a noncontact approach to positioning parts, which enables a fast throughput originally characteristic of self-assembly techniques. Furthermore, both DEP and EO have found widespread utilization in the transportation, separation, sorting, and assembly of nano- and microparticles and cells. − However, often because of the presence of forces that are difficult to measure and control (e.g., thermal forces, viscous forces in the fluid, particle-to-particle interactions, etc. ), particle placement using electrokinetic forces is less accurate than part placement performed with many pick-and-place systems …”