Yang Xiaolong, Liu Xin, Lu Yao, Zhou Shining, Gao Mingqian, Song Jinlong, Xu Wenji
Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education, Dalian University of Technology, Dalian 116023, People's Republic of China.
Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK.
Sci Rep. 2016 Apr 5;6:23985. doi: 10.1038/srep23985.
Patterns with controllable adhesion on superhydrophobic areas have various biomedical and chemical applications. Electrolyte jet machining technique (EJM), an electrochemical machining method, was firstly exploited in constructing dimples with various profiles on the superhydrophobic Al alloy surface using different processing parameters. Sliding angles of water droplets on those dimples firstly increased and then stabilized at a certain value with the increase of the processing time or the applied voltages of the EJM, indicating that surfaces with different adhesion force could be obtained by regulating the processing parameters. The contact angle hysteresis and the adhesion force that restricts the droplet from sliding off were investigated through experiments. The results show that the adhesion force could be well described using the classical Furmidge equation. On account of this controllable adhesion force, water droplets could either be firmly pinned to the surface, forming various patterns or slide off at designed tilting angles at specified positions on a superhydrophobic surface. Such dimples on superhydrophopbic surfaces can be applied in water harvesting, biochemical analysis and lab-on-chip devices.
在超疏水区域具有可控附着力的图案有多种生物医学和化学应用。电解质喷射加工技术（EJM）作为一种电化学加工方法，首次被用于通过不同的加工参数在超疏水铝合金表面构建具有各种轮廓的凹坑。随着EJM加工时间或施加电压的增加，水滴在这些凹坑上的滑动角先增大然后稳定在一定值，这表明通过调节加工参数可以获得具有不同附着力的表面。通过实验研究了限制液滴滑落的接触角滞后和附着力。结果表明，经典的Furmidge方程可以很好地描述附着力。由于这种可控的附着力，水滴既可以牢固地固定在表面上，形成各种图案，也可以在超疏水表面的指定位置以设计的倾斜角度滑落。超疏水表面上的这种凹坑可应用于集水、生化分析和芯片实验室设备。
