关键词: 微尺度, 接触角滞后, 滚动角, 模型, 能垒, 受力分析, 实验验证

Abstract: Hysteresis characteristics of droplet on inclined microstructured hydrophobic surfaces include contact angle hysteresis （CAH） and sliding angle （SA）. The SA model of droplet on microstructured hydrophobic surfaces，which has a relatively higher precision，is based on ideal droplet shape for calculating，ignoring the distortion of droplet caused by the combined action of gravity，CAH and energy barrier （EB）. In this paper，micro-pillar-structured hydrophobic surface was prepared from polydimethylsiloxane （PDMS），and CAH and SA were studied in terms of micro-pillar spacing and droplet size. With the increase of micro-pillar spacing，advancing contact angle of droplet with the same size basically remained unchanged，but receding contact angle decreased. For droplets with different sizes，on the same substrate，advancing contact angle and receding contact angle slightly changed，but CAH basically remained unchanged. Force analysis was conducted on the receding three-phase contact line，and the effects of CAH and EB on SA were analyzed from the perspectives of force and energy. By comparing theoretical value and practical value of SA，the significance of their effects on SA was confirmed，verifying the rationality of the analysis with respect to the effects of micro-pillar spacing on SA from the perspectives of force and EB respectively，which contributed to studying the more precise SA model.

Key words: microscale, contact angle hysteresis, sliding angle, model, energy barrier, force analysis, experimental validation