玫瑰之吻: 受生物啟發具有超疏水和高水滴吸附力之表面並應用於未來之無殘留轉印技術

Abstract

自從蓮葉效應被發現後，許多受生物啟發的超疏水表面其具備自潔淨特性者已經被大量製造。然而，最近幾年科學家被玫瑰花表面所深深吸引，其表面具有超疏水的特性和高水滴吸附力。此種現象是由花瓣上面微米尺度的凸起和奈米結構所產生。直至今日，許多研究者仍不知如何去製造出此等複雜的結構並使其真正拿來應用。為了去仿製花瓣的表面，我們發展出一種由下而上的方法：藉由簡單的酸雕刻技術來製作具有高水滴吸附力和自潔淨特性的超疏水聚二甲基矽氧烷(PDMS)。此類花瓣的聚二甲基矽氧烷其有35微米的寬度、奈米皺褶約在500奈米和小於100奈米的奈米結構。在長時間的檢測下，其也能展現大於150度的水滴接觸角。這些結論僅來自於其表面形貌的改變而與化學修飾並不相關。其展現的超疏水特性至少能維持一個月。此外，pH值從1到14、具有腐蝕性的水溶液在聚二甲基矽氧烷表面上也可以展現出高的水滴接觸角。更甚者，此類花瓣展現了高水滴吸附力達到35.81 N/m2。我們使用此類花瓣聚二甲基矽氧烷當作一個具黏性的手掌來搬運一5 mg的水滴，從一超疏水和自潔淨的聚二甲基矽氧烷表面搬運至親水的矽晶圓表面上。除此之外，從酸雕刻技術得來的兩種超疏水表面讓我們得以用來製造一個新型無殘留的印章。其超疏水且對水滴具吸附力的區域可用於將染料從印章轉移至紙上。而超疏水具備自潔淨的區域可以避免染料沾附上去。以此方式，這種新世代的超疏水表面能夠廣泛的使用在生物科技、微流體系統和工業領域。

Many bio-inspired superhydrophobic surfaces with self-cleaning property have been fabricated since “Lotus effect” was discovered. However, scientists were fascinated by the petal’s surface which has superhydrophobicity and high water adhesion in recent years. The phenomenon is induced by the microscale convex and nanostructures upon the petal. So far, researchers have perplexed how to manufacture the complicated topography and applied it to reality. To mimic the petal’s surface, we developed a bottom-up method by the simple acid texture technique to fabricate the superhydrophobic PDMS surface with high water adhesion and self-cleaning ability. The resulting petal-like PDMS had convexes about 35 μm in diameter, nanowrinkles around 500 nm in width and nanostructures less than 100 nm. A high water contact angle larger than 150° was displayed, even after a long-time duration test. These results caused only by morphology changing instead of chemical modification. The superhydrophobicity could maintain at least a month. Besides, the corrosive solutions range from pH value 1 to 14 also displayed high contact angles on the PDMS surface. Moreover, the petal-like PDMS exhibited the high water adhesion up to 35.81 N/m2. We used the petal-like PDMS surface as a sticky palm to transport a 5 mg water droplet from the superhydrophobic and self-cleaning PDMS to the hydrophilic silicon wafer. In addition, the two superhydrophobic surfaces from the acid texture technique allowed us to fabricate a modern nonresidual stamp. The superhydrophobic and water adhesive area is applicable to transport the dye from the stamp to a paper. The superhydrophobic and self-cleaning region avoids the adhesion of dye. Thus, the new-generation superhydrophobic surface can be wildly applied to biotechnology, MEMS and industry.