| 摘要: |
| 针对化学气相沉积、自组装技术等表面制备方法存在化学污染、表面结合强度低等问题,运用飞秒激光在单晶硅表面加工正方形微凹坑阵列制备梯度润湿性表面,使用白光干涉仪、扫描电子显微镜、能谱仪和接触角测量仪分别测量单晶硅表面粗糙度、微观形貌、化学成分及接触角。 通过改变激光能量密度制备不同梯度润湿性表面,研究不同激光能量密度下液滴在梯度润湿性表面上的铺展规律。 结果表明:随激光能量密度增大,表面粗糙度参数算术平均高度、均方根斜率和界面扩展面积比整体呈增大趋势,表面接触角整体呈减小趋势。 由于激光能量密度增大导致的单晶硅表面平行微凹槽、重凝层及不规则微纳结构使均方根斜率、界面扩展面积比及表面接触角出现波动。 液滴在梯度润湿性表面定向铺展分为加速与减速两个阶段,减速阶段速度伴随明显波动现象,小体积液滴的铺展速度更快。 实现了飞秒激光高精度、非接触、过程可控的梯度润湿性表面制备,结果可为制备单晶硅微流控器件提供理论参考。 |
| 关键词: 飞秒激光 单晶硅 梯度润湿性 接触角 |
| DOI：10.11933/j.issn.1007-9289.20210506001 |
| 分类号:TN249 |
| 基金项目:国家自然科学基金(51977061)；湖北省自然科学基金(2019CFB163)；湖北省教育厅(D20181401)资助项目 |
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| Gradient Wettability of Monocrystalline Silicon Surface Prepared by Femtosecond Laser |
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YANG Qibiao, BIAN Ruonan, WANG Jie, ZHOU Wei, LIU Dun
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School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068 , Chnia
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| Abstract: |
| Aiming at the problems of chemical vapor deposition, self-assembly technology and other surface preparation methods such as chemical pollution and low surface bonding strength, femtosecond lasers are used to process square micro-pit arrays on the surface of monocrystalline silicon to prepare gradient wettability surfaces. A white light interferometer, scanning electron microscope, energy spectrometer and contact angle measuring instrument are used respectively to measure the surface roughness, micro morphology, chemical composition and contact angle of monocrystalline silicon. The different gradient wettability surfaces are prepared by changing the laser fluence, and the spread mechanism of droplets on the gradient wettability surface under different laser fluence is studied. The results show that with the increase of the laser fluence, the surface roughness parameters such as the arithmetic average height, root mean square slope and interface expansion area ratio show an overall increasing trend, and the surface contact angle shows an overall decreasing trend. The parallel microgrooves, recast layers and irregular micro-nano structures on the surface of single crystalline silicon caused by the increase of the laser fluence induce fluctuations of the root mean square slope, the interface expansion area ratio, and the surface contact angle. The directional spreading process of droplets on the gradient wettability surface can be divided into two stages: the acceleration stage and the deceleration stage. The speed of the deceleration stage is accompanied by obvious fluctuations, and the spreading speed of small-volume droplets is faster. The experiment has realized the high-precision, non-contact, and processcontrollable gradient wettability surface preparation of femtosecond laser. The results can provide a theoretical reference for the preparation of monocrystalline silicon microfluidic devices. |
| Key words: femtosecond laser single crystalline silicon gradient wettability contact angle |
