Jagdheesh R
School of Mechanical and Manufacturing Engineering, The University of New South Wales , Sydney NSW 2052, Australia.
Langmuir. 2014 Oct 14;30(40):12067-73. doi: 10.1021/la5033527. Epub 2014 Oct 3.
Ultrashort pulse laser (USPL) machining/structuring is a promising technique to create a micropattern on a material surface with very low distortion to the peripheral area or high precession. Thin sheets of alumina (Al2O3) are micromachined with ultraviolet laser pulses of 6.7 ps, to create a superhydrophobic surface by single-step processing. USPL patterned micropillars and microholes have been fabricated with a range of pulses varying from 100 to 1200 pulses/unit area. The impact of the number of pulses/unit area with respect to the geometry and static contact angle measurements has been studied. The surface is free from cracks, and the melting effect is well-pronounced for the blind microhole structures. An energy dispersive X-ray spectroscopy study revealed a marginal change in the elemental composition of the laser-patterned surface. The results show that the geometry of the laser-machined pattern plays a major role in changing the wetting properties rather than the chemical changes induced on the surface. The micropillars exhibited a consistent superhydrophobic surface with a static contact angle measurement of 150° ± 3°.
超短脉冲激光（USPL）加工/结构化是一种很有前景的技术，可在材料表面创建微图案，对周边区域的失真非常小或精度很高。用6.7皮秒的紫外激光脉冲对氧化铝（Al2O3）薄片进行微加工，通过单步加工创建超疏水表面。已制造出具有100至1200脉冲/单位面积范围内一系列脉冲的USPL图案化微柱和微孔。研究了单位面积脉冲数对几何形状和静态接触角测量的影响。表面无裂纹，对于盲孔微结构，熔化效应很明显。能量色散X射线光谱研究表明，激光图案化表面的元素组成有轻微变化。结果表明，激光加工图案的几何形状在改变润湿性方面起主要作用，而不是表面引起的化学变化。微柱呈现出一致的超疏水表面，静态接触角测量值为150°±3°。
