AC electrothermal mixing for high conductive biofluids by arc-electrodes

作者:Meng, Jiyu; Li, Shanshan*; Li, Junwei; Yu, Chengzhuang; Wei, Chunyang; Dai, Shijie*
来源:Journal of Micromechanics and Microengineering, 2018, 28(6): 065004.
DOI:10.1088/1361-6439/aab39b

摘要

As a platform to mix the bioagents (i.e. serum, urine), we take advantage of the alternating current electrothermal (ACET) effect which is quite suitable for rapid pumping/mixing of high conductive biomicrofluids. Here we demonstrate the concept of a high-efficient mixing microfluidic chip as a basic unit to provide rapid mixing for lab-on-a-chip applications. As an active mixer, two streams are introduced into a ring-shape microchamber by a passive flow rate regulator, and then the microfluids in the chamber are actuated by a nonuniform electric field with a phase shift of 180 degrees. It shows perfect mixing performance by arranging four arc-electrodes around the ring-shape microchamber subsequently. Taking the Joule heating and conductivity/permittivity changes into consideration, a temperature dependent fully coupled numerical model is presented. Then, the effects of applied voltages on mixing performance and temperature rise are provided to get an optimized design for ACET mixer. Moreover, the arrangement of the electrode array is analyzed to show the effects of electrode patterns on the swirls and mixing efficiencies. Since all the electrodes here are located along a ring-shape central microchamber, the ring-shape micromixer is quite suitable to function as a compact element modular for integrated microfluidic chips.