The wettability property of a material surface is highly dependent on the topography of the surface micro/nanostructure. Femtosecond (fs) laser can be used to fabricate various kinds of surface micro/nanostructures. We present parallel microgroove arrays with unique cross-sectional profiles on the surface of an aluminum foil induced by varying the laser fluence and the scanning spacing. The laser textured aluminum surface shows directional spreading of water and inherently hydrophilic aluminum surface becomes superhydrophilic. A water droplet spreads highly anisotropically on the processed area and flows preferentially along the microgrooves. The maximum average spreading velocity of water droplet along the laser textured microgrooves is ~ 200 mm/s, while it is much slower in the direction perpendicular to the microgrooves, which is 41 mm/s. Moreover, the spreading distance of water and time t in both directions have a linear relation with t^1/2. The fast-self-spreading motion of water along the microgroove is due to its capillary pressure and a local energy barrier at the boundary between two parallel microgrooves. In addition, laser-modified surface roughness and laser-altered chemical composition on the aluminum surface play a role in enhancing the superhydrophilicity and the directional water spreading behavior. Our research can be applied in the fields of microfluidics, lab-on-chip technology, chemical and biological sensors and heat transfer devices.

材料表面的润湿性高度依赖于表面微观/纳米结构的形貌。飞秒（fs）激光可用于制造各种类型的表面微/纳米结构。我们介绍了通过改变激光注量和扫描间距而在铝箔表面上具有独特横截面轮廓的平行微槽阵列。激光纹理化的铝表面显示出水的定向散布，并且固有的亲水性铝表面变得超亲水。水滴在加工区域上高度各向异性地分布，并优先沿着微沟槽流动。水滴沿激光纹理化的微沟槽的最大平均扩展速度为〜200 mm / s，而在垂直于微沟槽的方向上为41 mm / s则要慢得多。吨在两个方向上具有带有线性关系吨^1/2。水沿着微沟槽的快速自我扩散运动是由于其毛细压力和两个平行微沟槽之间边界处的局部能垒。此外，铝表面的激光改性表面粗糙度和激光改变的化学成分在增强超亲水性和定向水扩散行为方面也起着作用。我们的研究可应用于微流控技术，芯片实验室技术，化学和生物传感器以及传热设备领域。