梯形截面微流控芯片中电渗流的实验检测

Experimental study of electroosmotic flow in a trapezoidal microfluidic chip

设计和制作了一种具有梯形截面的双T形结构微流控芯片,对其微通道内表面和几何参数进行了测试。基于电流监测法,测量了微流控芯片通道内的电渗流速度,得到实验结果与理论模型一致;并分析了电场强度、溶液浓度等对电渗流的影响。实验结果表明:1)梯形截面微流控芯片中电渗流速度与电场强度为线性关系,电场强度增大,电渗流速度成比例增大;2)随着溶液浓度的增加,电渗流速度非线性降低。最后提出了微流控芯片在应用过程中需要注意的综合因素。

A kind of microfluidic chip with double-T structure and trapezoidal cross section was designed and manufactured,the surface and geometric parameters of the microchannels were also tested. Based on the current-monitoring method,electroosmotic flow（ EOF） velocity in the trapezoidal microchannel was achieved on the experiment,which was consistent with that of the theoretical model. The effects of electric strength and ionic concentration on EOF were also analyzed. The experimental results show that：1） the EOF velocity in the trapezoidal microchannel is proportional to the electric strength. 2） EOF velocity decreases with the increase of ionic concentration nonlinearly. The comprehensive factors on the application of microfluidic chip were put forward finally.