Preprint Article Version 1 This version is not peer-reviewed

Electrode Cooling Effect on Out-of-Phase Electrothermal Streaming in Rotating Electric Fields

Version 1 : Received: 27 September 2017 / Approved: 27 September 2017 / Online: 27 September 2017 (12:11:34 CEST)

A peer-reviewed article of this Preprint also exists.

Liu, W.; Ren, Y.; Tao, Y.; Chen, X.; Wu, Q. Electrode Cooling Effect on Out-Of-Phase Electrothermal Streaming in Rotating Electric Fields. Micromachines 2017, 8, 327. Liu, W.; Ren, Y.; Tao, Y.; Chen, X.; Wu, Q. Electrode Cooling Effect on Out-Of-Phase Electrothermal Streaming in Rotating Electric Fields. Micromachines 2017, 8, 327.

Journal reference: Micromachines 2017, 8, 327
DOI: 10.3390/mi8110327

Abstract

In this work, we focus on investigating electrothermal flow in a rotating electric field (ROT-ETF), with primary attention paid to the horizontal traveling-wave electrothermal (TWET) vortex induced at the center of the electric field. The frequency-dependent flow profiles in the microdevice are analyzed using different heat transfer models. Accordingly, we address in particular the importance of electrode cooling in ROT-ETF as metal electrodes of high thermal conductivity while substrate material of low heat dissipation capability are employed to develop such microfluidic chips. Under this circumstance, cooling of electrode array due to external natural convection on millimeter-scale electrode pads for external wire connection occurs and makes the internal temperature maxima shift from the electrode plane to a bit of distance right above the cross-shaped interelectrode gaps, giving rise to reversal of flow rotation from a typical repulsion-type to attraction-type induction vortex, which is in good accordance with our experimental observations of co-field TWET streaming at frequencies on the order of reciprocal charge relaxation time of the bulk fluid. These results point out a way to make a correct interpretation of out-of-phase electrothermal streaming behavior, which holds great potential for handing high-conductivity analytes in modern microfluidic systems.

Subject Areas

electrothermal flow; rotating electric field; out-of-phase smeared structural polarization; electrode cooling; external natural convection; co-field flow rotation

Readers' Comments and Ratings (0)

Leave a public comment
Send a private comment to the author(s)
Rate this article
Views 0
Downloads 0
Comments 0
Metrics 0
Leave a public comment

×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.