Alternating current electrothermal micromixer with thin film resistive heaters

• Published in: Advances in mechanical engineering Vol. 8; no. 5
• Main Authors: Zhang, Feng, Chen, Han, Chen, Bo, Wu, Jiankang
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.05.2016; Sage Publications Ltd; SAGE Publishing
• Subjects: Alternating current; Computational fluid dynamics; Computer simulation; Conductivity; Efficiency; Electric fields; Electrodes; Fluid flow; Fluids; Glass substrates; Heaters; Heating equipment; Laminar flow; Laminar mixing; Mathematical models; Microchannels; Reynolds number; Stretching; Temperature gradients; Thin films; Vortices; alternating current electrothermal flow; multiphysics; mixing; Microfluidics; resistive heater
• ISSN: 1687-8132; 1687-8140
• DOI: 10.1177/1687814016646264

Alternating current electrothermal flow has been extensively used for mixing of fluids in microfluidic systems. This work presents a novel approach to mixing two laminar flow streams in microchannels. The micromixer consists of a pair of asymmetric planar alternating current electrodes disposed along a fluidic channel and a thin film resistive heater below the electrode. Multiphysics (fluid flow, temperature, electrical, and concentration fields) in the micromixer is studied by numerical simulation method. The results indicate that external heating by the thin film resister leads to flow body forces that are proportional to the temperature gradient and chaotic stretching and folding of fluid material lines. Enhancement of mixing is demonstrated by numerical simulation results. Effects of size and location of the thin film resistive heater on mixing efficiency are also investigated.