Microfluidics and Nanofluidics

, Volume 16, Issue 1–2, pp 167–178 | Cite as

Optimization of planar interdigitated microelectrode array for biofluid transport by AC electrothermal effect

Research Paper


Point-of-care (POC) diagnostics is one of the most important applications for microfluidic research. However, the development of microfluidic POC devices needs to overcome great obstacles to reach market. One challenge is to find a chip-scale pumping strategy that is of low cost, small size, and light weight. Because of their simple implementation, electrokinetic techniques have been extensively investigated as a promising candidate for realizing disposable pumps, with the majority of research effort focusing on direct current and alternating current (AC) electroosmosis. As POC applications often need to handle conductive biofluids with medium to high salt content, AC electrothermal (ACET) effect has been investigated recently for pumping of biofluids, albeit with less than desirable pumping performance. In order to achieve effective on-chip ACET micropumps, this paper presents one of the first efforts in optimizing ACET micropump design utilizing planar interdigitated electrodes. The effects of electrode dimensions on pumping rate were numerically studied using COMSOL Multiphysics and MATLAB, and an optimal ratio of electrode geometry was found for various pumping scenarios. The optimal geometry ratio was tested to be valid over a wide range of electrode characteristic lengths, AC signals, and fluid ionic strengths. Experimental validation of the simulation results was also conducted, and higher flow velocities over prior reports were consistently demonstrated by optimized electrode arrays.


Micropump AC electrokinetics AC electrothermal effect Interdigitated microelectrodes 



This study was supported by the US National Science Foundation under Grant No. ECS-0448896. Microfabrication of this research was conducted at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, US Department of Energy.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Department of Electrical Engineering and Computer ScienceThe University of TennesseeKnoxvilleUSA

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