微流控光学透镜阵列内芯表面的电润湿特性测量

Investigation of Electrowetting Properties on the Core-Surface of Optofluidic Lens Array

采用特定的"导电基片/绝缘膜层"微透镜阵列内芯材料,研究其表面的介质上电润湿(EWOD)特性。利用图像采集与数据处理方法测量了0～60 V电压范围内硫酸钠水溶液液滴在"不锈钢基片/Parylene绝缘层"芯片表面的接触角变化数据,通过EWOD理论模型计算得到硫酸钠溶液的表面张力值,此值与理论值相吻合。进而计算了内芯与液滴的界面张力,这种方法可用于一般固液界面张力的测量。

The properties of electrowetting on dielectric （EWOD） on the core-surface of optofluidic lens-array are investigated with specific ＂conductive substrate/insulation film＂ material. Adopting the image acquisition and data processing, the contact angle of the Na2 SO4 solution droplets in the ＂stainless steel substrate/Parylene insulating layer＂ chip surface is meas- ured in the range of the voltage of 0-60 V. The theoretical surface tension of Na2 SO4 solution is in good agreement with the results of the method based on the EWOD theory in this paper. Moreover, the interfacial tension coefficient of the inner core and droplet is derived, which can be used to measure general solid-liquid interfacial tension.