点面电极系统低频流体驱动机理

Mechanism of fluid flow at low frequency in point-plane electrode system

为了弥补传统交流电动力学理论在解释微流体反向流动方面的不足,开发了一种新型三维点面电极系统并进行微流体驱动实验,分析了低频条件下电化学、交流电热等因素对微流体驱动的影响.实验结果表明,点面电极系统中广频范围内(10～3×106Hz)的微流体流动方向均为由点电极流向面电极,这一现象与利用交流电渗理论预测的流体流动方向相反.实验验证了低频条件下电化学反应在流体流动中的重要作用.结果表明,电化学反应是点面电极系统中低频条件下微流体流动现象的主要因素.

To make up the deficiency of traditional ac electrohydrodynamics in explaining fluid flowing in opposite direction,a 3D point plane electrode system is devised to carry out microfluidic driving experiments,and the influence of electrochemistry and ac electro-thermal on microfluidic driving under low ac frequency has been analyzed.It is found that the flow direction under ac range of 10 Hz～3 MHz in the device is point to plane all the time,which is opposite to the prediction from theory of ac electro-osmotic（ACEO）.The experiments verifies the leading role of electrochemical reaction under low ac frequency,and the result indicates that the leading influencing factor of the phenomenon of microfluidic under low ac frequency in point plane electrode system is electrochemistry.