Nanotechnology for Bio-mimetic Dry Adhesives

在本篇論文中，成功的利用電子束微影技術和化學氣相層積製造奈米級仿生黏著層，壁虎的腳上有很多高密度的角質奈米纖毛，使得它可以在光滑或是粗糙的表面上行走，實驗中成功地利用高分子光阻材料和奈米碳管製造出高密度的纖毛，並且利用原子力顯微鏡和特別的探針作為量測吸附力的設備，利用光阻奈米纖毛分析其吸附力和纖毛半徑、密度、數量和產生凡得瓦力實際面積的相互關係，而奈米碳管所產生的黏著力已經和壁虎的腳毛黏著力到了同一個等級了。而對於壁虎腳毛的自我清潔功能也做了驗證，壁虎腳毛之所以如此斥水的原因在於奈米等級的間隙，使得空氣保留在間隙中，水無法陷入間隙，產生較大的水滴接觸角，使得水可以輕易的將附著於表面的灰塵微粒帶走，而造成自我清潔效應。This work presents the fabrication and characterization of nano-fibrils mimicking gecko foot-hairs for enhanced dry adhesion. High contact area ratio of the polymer and carbon nanotube fibrils is achieved, respectively, using e-beam lithography and chemical vapor deposition. The adhesion forces from gecko foot-hairs and the artificial fibrils are measured with a customized AFM tip to evaluate the effects of different materials, surface density, the number of fibrils and the area of real contact. With the water-vapor assisted deposition, the surface density of the carbon nanotubes is optimized for comparable adhesion forces to gecko foot-hairs. Although the photoresist and the CNT are both intrinsically hydrophilic, superhydrophobic behavior was obtained when they were patterned or synthesized into nano-fibrils.致謝......................................................Ⅰ 摘要......................................................Ⅱ Abstract..................................................Ⅲ 目錄......................................................Ⅳ 圖目錄....................................................Ⅶ 表目錄..................................................ⅩⅠ 第一章 緒論.............................................1 1.1 前言.............................................1 1.2 研究動機與目的...................................1 1.3 文獻探討.........................................1 1.4 論文架構........................................13 第二章 奈米級黏著設計與原理............................14 2.1 黏著力產生......................................14 2.1.1 奈米尺寸的選擇..................................14 2.1.2 結構穩定性標準..................................21 2.1.2.1 纖毛彎曲........................................21 2.1.2.2 側向吸附........................................24 2.2 自我潔淨效應....................................28 第三章 實驗製程........................................31 3.1 電子束微影（EBL）製程...........................31 3.1.1 電子束微影介紹................................31 3.1.2 電子束微影實驗設備介紹........................32 3.1.3 電子束微顯影的限制............................34 3.1.4 正光阻製作仿生奈米黏著層......................36 3.1.5 負光阻製作不同密度的奈米毛....................44 3.2 化學氣相層積奈米碳管製程........................48 3.2.1 碳米碳管簡介....................................48 3.2.2 奈米碳管的製程方法..............................48 第四章 量測設備........................................53 4.1 原子力顯微鏡（AFM）量測黏著力...................53 4.1.1 原子力顯微鏡探針..............................53 4.1.2 量測方法......................................55 4.2 測角儀量測水滴接觸角............................59 第五章 實驗結果與討論..................................63 5.1 吸附力量測......................................63 5.1.1 光阻奈米纖毛的吸附力............................63 5.1.2 奈米碳管的吸附力................................81 5.1.3 光阻奈米纖毛吸附力結果討論......................83 5.2 接觸角結果......................................84 5.2.1 正光阻纖毛的接觸角量測結果....................86 5.2.2 奈米碳管水滴接觸角量測結果....................89 第六章 結論與未來展望.................. ...............91 6.1 關於仿生奈米級黏著科技..........................91 6.2 關於仿生奈米黏著之自我潔淨效應..................91 6.3 未來展望........................................92 參考資料.................................................9