具使水流自驅動結構漸受重視。自然界中許多生物材料，如蜘蛛絲仙人掌的楔狀結構，結合了拉普拉斯壓力梯度和親水表面，具有單方向濕潤能力。此研究中，我們設計並製造一系列具不同楔狀結構之溝槽圖樣以優化水滴之單方向性濕潤與傳輸。
具可控濕潤性與單方向濕潤行為之聚乳酸試片以3D列印結合表面改質方式製備。表面改質主要分兩步驟進行：先以大氣電漿在一定的工作距離活化聚乳酸表面，再嫁接(3-氨基丙基)三乙氧基硅烷之水解溶液。利用靜態接觸角量測其親水性並以數位攝影機觀察其動態濕潤行為。以原子力顯微鏡分析不同(3-氨基丙基)三乙氧基硅烷嫁接處理方式之表面形貌。化學成分則以X光光電分析儀確認。雷射共軛焦顯微鏡用來確認印製樣品與設計結構之精準度。藉由結構設計與表面改質之溝槽圖樣具單方向性濕潤行為，具潛力被應用於許多領域。

The self-driving structure to orientate the water flow has attracted increasing attention. Inspired by the wedgelike structures of many biological materials in nature, such as spider silks and cactus spines, unidirectional wetting can be realized by combining Laplace pressure gradient and hydrophilic surface. In this study, we designed and fabricated a series of groove patterns with various wedgelike structures to optimize unidirectional wetting and transportation of water droplets.
Polylactic acid (PLA) samples with tunable wettability and unidirectional wetting behavior were fabricated by combining 3D printing and surface modification. Surface modification consisted of two steps: the atmospheric pressure plasma was used to activate the PLA surface at a specific working distance, then proceeded with grafting (3-aminopropyl) triethoxysilane (APTES) in hydrolysis solution onto plasma-treated PLA. The hydrophilicity and dynamic wetting behavior were evaluated by measuring static contact angle and observed by a digital camera. To verify the quality of the APTES grafting, atomic force microscopy (AFM) was used to characterize the morphology after different treatments. The chemical composition of the outermost hydrolyzed APTES was confirmed by X-ray photoelectron spectroscopy (XPS). Furthermore, a laser confocal microscope was employed to confirm the accuracy of the printed patterns and the designed structures. Through structural design and surface modification, groove patterns with unidirectional wetting behavior can be potentially applied in many fields.

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