超疏水表面的研究一直以來是備受矚目廣泛研究的課題，在表面上製作微米甚至奈米尺寸等級的柱子，透過水珠靜態或是動態上的分析，可以了解水珠在不同情況的受力情形與最終狀態為何，讓我們可以歸納出一套製作超疏水表面的參考參數。本研究利用了CNC微鑽法雕刻出不同尺寸的模具，並透過翻模及PDMS蝕刻製備出百微米尺度的超疏水表面，以上製程透過簡單的設備與較低的成本能快速地做出表面。在靜態分析上，我們在不同尺寸的表面輕放水珠，觀察靜態接觸角與滑落角，找出水珠狀態的轉換位置，並與文獻做比較。發現由於我們的結構在尺度上比文獻中大了一到兩個層級，所以無法完全適用其中的理論，但我們歸納出一個簡單的幾何判別，找出百微米尺度的疏水表面狀態轉換位置。在動態分析上，我們將水滴從不同高度滴下，水珠會部分彈起或是穿越柱子浸濕表面，但在特定表面下水珠能完全彈起，分析水珠的受力情形，我們的表面應當不會讓水珠完全彈起，這與實驗結果不一致。而在液滴撞擊圓柱陣列表面時，我們發現，當水滴撞擊然後陷入圓柱，最後靜止於表面時，水滴會慢慢地往上移動。將水珠的移動距離標準化後，發現水珠移動的速率跟水珠與圓柱的接觸面積有關。

In this study, we have investigated the static and dynamic wetting behavior of the surface with Polydimethylsiloxane (PDMS) micropillars array at hundreds of micros scale. The PDMS micropillars array was obtained by casting the cylindrical wells on the polymethyl methacrylate substrate, which were produced by computer numerical control (CNC) machine. For sessile drops, it is found that the droplet remained Cassie state at small W/D, where W is the pillar spacing and D is the pillar diameter. As W/D increased, the droplet gradually moved to the Cassie-Wenzel transition state. When W/D reached approximately to 2H/D where H is the height of micropillars, the contact angle of the sessile drop decreased drastically and the sessile drop was on the Wenzel state. In addition, we demonstrated the static results of larger droplets and showed that the volume of the drops did not affect the transition. Also, the sliding-off results can support the transition results. In the case of impinging experiments, water droplet can bounce on some micropillar arrays, which is against the pressure balance calculated. However, in some cases, we found that droplet could move upward after impinging and falling in the micropillar array. By normalizing the moving distance of the droplet, we concluded that the moving velocity of the droplet is related to the liquid-solid contact area.

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