title: Rectangle-capped and tilted micropillar array for enhanced anisotropic anti-shearing in biomimetic adhesion.
abstract: Dry adhesion observed in the feet of various small creatures has attracted considerable attention owing to the unique advantages such as self-cleaning, adaptability to rough surfaces along with repeatable and reversible adhesiveness. Among these advantages, for practical applications, proper detachability is critical for dry adhesives with artificial microstructures. In this study, we present a microstructured array consisting of both asymmetric rectangle-capped tip and tilted shafts, which produce an orthogonal anisotropy of the shearing strength along the long and short dimensions of the tip, with a maximum anti-shearing in the two directions along the longer dimension. Meanwhile, the tilt feature can enhance anisotropic shearing adhesion by increasing shearing strength in the forward shearing direction and decreasing strength in the reverse shearing direction along the short dimension of the tip, leading to a minimum anti-shearing in only one of the two directions along the shorter dimension of the rectangular tip. Such a microstructured adhesive with only one weak shearing direction, leading to well-controlled attachment and detachment of the adhesive, is created in our experiment by conventional double-sided exposure of a photoresist followed by a moulding process.
authors: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
authors: Yue
authors: Y
authors: Wang
authors: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
authors: Xiangming
authors: X
authors: Li
authors: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
authors: Hongmiao
authors: H
authors: Tian
authors: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
authors: Hong
authors: H
authors: Hu
authors: State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
authors: Yu
authors: Y
authors: Tian
authors: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China jyshao@mail.xjtu.edu.cn.
authors: Jinyou
authors: J
authors: Shao
authors: Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
authors: Yucheng
authors: Y
authors: Ding
mesh_terms: D000269:Adhesives / Q000737:chemistry*; D016880:Anisotropy; D040761:Biomimetic Materials / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D066330:Printing, Three-Dimensional; D033081:Shear Strength; D013718:Tensile Strength
chemical_list: D000269:Adhesives
keywords: anisotropic anti-shearing; biomimetic; dry adhesive; microstructure