A Simple Way To Achieve Pattern-Dependent Tunable Adhesion in Superhydrophobic Surfaces by a Femtosecond Laser
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- 作者：Dongshi Zhang ; Feng Chen ; Qing Yang ; Jiale Yong ; Hao Bian ; Yan Ou ; Jinhai Si ; Xiangwei Meng ; Xun Hou
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2012
- 出版时间：September 26, 2012
- 年：2012
- 卷：4
- 期：9
- 页码：4905-4912
- 全文大小：614K
- 年卷期：v.4,no.9(September 26, 2012)
- ISSN：1944-8252
文摘
In this paper, we present a new approach to the tunable adhesive superhydrophobic surfaces consisting of periodic hydrophobic patterns and superhydrophobic structures by femtosecond (fs) laser irradiation on silicon. The surfaces are composed of periodic hydrophobic patterns (triangle, circle, and rhombus) and superhydrophobic structures (dual-scale spikes induced by a fs laser). Our results reveal that the adhesive forces of as-prepared surfaces can be tuned by varying the area ratio (ARs-h) of superhydrophobic domain to hydrophobic domain, thus resulting in tunable static and dynamic wettabilities. By increasing ARs-h, (i) the static wetting property, which is characterized by the minimum water droplet volume that enables a droplet to land on the surface, can be tailored from 1 渭L to 9 渭L; (ii) the sliding angle can be flexibly adjusted, ranging from >90掳 (a droplet cannot slide off when the sample is positioned upside down) to 5掳; and (iii) the droplet rebound behaviors can be modulated from partial rebound to triple rebound. In addition, the Cassie鈥揃axter model and the sliding angle model are used to speculate the contact angles and sliding angles to provide potentially theoretical models to design slippery-to-sticky superhydrophobic surfaces. The tunable adhesive superhydrophobic surfaces achieved by fs laser microfabrication may be potentially used in microfluidic systems to modulate the mobility of liquid droplets.