In nature, geckos have developed complex adhesion structures capable of smart adhesion, which is the ability to cling to different smooth and rough surfaces, even ceilings, and detach at will. The hierarchical structu...In nature, geckos have developed complex adhesion structures capable of smart adhesion, which is the ability to cling to different smooth and rough surfaces, even ceilings, and detach at will. The hierarchical structure of gecko foot hairs consists of microscale setae, branches and nanoscale spatulae, which contributes to their strong adhesion on different surfaces. In this paper, we propose a simple and low-cost method for fabricating two-level high aspect ratio microfiber arrays that mimic gecko foot hairs. SU-8 photoresist was used and single-level SU-8 microfiber arrays were obtained by a thick film photolithography process. Single-level polydimethyl-siloxane (PDMS) microfiber arrays were also obtained by a micromolding process and the master template for this process was fabricated using inductively coupled plasma (ICP) technology. Using the silicon mold with deep-hole arrays as a substrate, an SU-8 layer with microhole arrays was added to it using thick film photolithography and it formed a double stack mold from which the two-level hierarchical PDMS microfiber arrays were replicated. Water contact angle tests showed that the two-level hierarchical structures are extremely hydrophobic (about 148.5° compared with the Tokay gecko's 160°).展开更多
Gecko's excellent adhesion ability is thought to derive from van der Waals force generated between the millions of keratinous hairs/setae and the contact surface.Fabricating highly gecko-inspired foot-hair becomes...Gecko's excellent adhesion ability is thought to derive from van der Waals force generated between the millions of keratinous hairs/setae and the contact surface.Fabricating highly gecko-inspired foot-hair becomes one of the key technologies to realize the three-dimensional-obstacle-free motion of robot.Researchers have fabricated various gecko-like foot-hair arrays which have leaning,large end,and hierarchical structures.Those significant works are summarized and suggestions for future work are proposed in this paper.展开更多
基金supported by the National Natural Science Foundation of China(91023032,51005091,50775090)the Fundamental Research Funds for the Central Universities of China(2010ZD004)the Postdoctoral Science Foundation of China(20100470052)
文摘In nature, geckos have developed complex adhesion structures capable of smart adhesion, which is the ability to cling to different smooth and rough surfaces, even ceilings, and detach at will. The hierarchical structure of gecko foot hairs consists of microscale setae, branches and nanoscale spatulae, which contributes to their strong adhesion on different surfaces. In this paper, we propose a simple and low-cost method for fabricating two-level high aspect ratio microfiber arrays that mimic gecko foot hairs. SU-8 photoresist was used and single-level SU-8 microfiber arrays were obtained by a thick film photolithography process. Single-level polydimethyl-siloxane (PDMS) microfiber arrays were also obtained by a micromolding process and the master template for this process was fabricated using inductively coupled plasma (ICP) technology. Using the silicon mold with deep-hole arrays as a substrate, an SU-8 layer with microhole arrays was added to it using thick film photolithography and it formed a double stack mold from which the two-level hierarchical PDMS microfiber arrays were replicated. Water contact angle tests showed that the two-level hierarchical structures are extremely hydrophobic (about 148.5° compared with the Tokay gecko's 160°).
基金supported by the National Natural Science Foundation of China (Key Project) (60535020 and 50805076)National High-Tech Research & Development Program of China (2007AA04Z201)+1 种基金Natural Science Foundation of Jiangsu Province (BK2007202)Foundation of State Key Laboratory of Solid Lubrication
文摘Gecko's excellent adhesion ability is thought to derive from van der Waals force generated between the millions of keratinous hairs/setae and the contact surface.Fabricating highly gecko-inspired foot-hair becomes one of the key technologies to realize the three-dimensional-obstacle-free motion of robot.Researchers have fabricated various gecko-like foot-hair arrays which have leaning,large end,and hierarchical structures.Those significant works are summarized and suggestions for future work are proposed in this paper.
