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

摘要： 倾斜微结构疏水表面液滴的滞后特性包括接触角滞后和滚动角。目前，具有较高精度的微结构疏水表面滚动角模型是以理想液滴形状为计算基础，忽略了重力、接触角滞后以及能垒引起的变形。本文以聚二甲基硅氧烷（PDMS）为基底，制备了方柱状微结构疏水表面，考虑疏水表面微观结构以及液滴大小两方面的因素，研究了倾斜微结构疏水表面液滴的滞后特性。从力和能量的角度对其影响机理进行了分析，通过滚动角理论值与实际值的比较发现，微方柱间距较大时，接触角滞后和能垒对滚动角影响显著，证实了该分析的合理性，为研究更加精确的滚动角模型奠定了理论基础。

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