Electrokinetic Phenomena in Pencil Lead-Based Microfluidics.

Yashar Bashirzadeh,Venkat Maruthamuthu,Shizhi Qian

doi:10.3390/mi7120235

Abstract

Fabrication of microchannels and associated electrodes to generate electrokinetic phenomena often involves costly materials and considerable effort. In this study, we used graphite pencil-leads as low cost, disposable 3D electrodes to investigate various electrokinetic phenomena in straight cylindrical microchannels, which were themselves fabricated by using a graphite rod as the microchannel mold. Individual pencil-leads were employed as the micro-electrodes arranged along the side walls of the microchannel. Efficient electrokinetic phenomena provided by the 3D electrodes, including alternating current electroosmosis (ACEO), induced-charge electroosmosis (ICEO), and dielectrophoresis (DEP), were demonstrated by the introduced pencil-lead based microfluidic devices. The electrokinetic phenomena were characterized by micro-particle image velocimetry (micro-PIV) measurements and microscopy imaging. Highly efficient electrokinetic phenomena using 3D pencil-lead electrodes showed the affordability and ease of this technique to fabricate microfluidic devices embedded with electrodes for electrokinetic fluid and particle manipulations.

Highlights

Microfluidic technology has become an important multi-disciplinary field for controlling and sensing in areas as diverse as electronics and tissue engineering
Alternating current electroosmosis (ACEO) flow is generated at electrode surfaces subject to an applied alternating current (AC) electric field [6]
To achieve the aforementioned electrokinetic phenomena, micro-electrodes must be fabricated within the microfluidic device for either applying the electric field or inducing charges at the surface of the floating electrode

Summary

Introduction

Microfluidic technology has become an important multi-disciplinary field for controlling and sensing in areas as diverse as electronics and tissue engineering. Samples and reagents have been transported through microchannels embedded in a chip, and, micro-electrodes of different materials have been used for manipulation, control and/or detection of fluids and samples [1,2] Electrokinetic transport processes such as electroosmosis, induced charge electroosmosis (ICEO) and dielectrophoresis (DEP) using electric fields have become important techniques to manipulate fluids and particles in various microfluidic applications [3,4]. To achieve the aforementioned electrokinetic phenomena, micro-electrodes must be fabricated within the microfluidic device for either applying the electric field (in ACEO and DEP applications) or inducing charges at the surface of the floating electrode (in ICEO applications)

Methods

Results

Discussion

Conclusion