The current research on gecko-inspired dry adhesives is focused on micropillar arrays with different terminal shapes, such as flat, spherical, mushroom, and spatula tips. The corresponding processing methods are mostly chemical methods, including lithography, etching, and deposition, which not only are complex, expensive, and environmentally unfriendly, but also cannot completely ensure microstructural integrity or performance stability. The present study demonstrates a high-precision, high-efficiency, and green method for the fabrication of a gecko-inspired surface, which can promote its application in dexterous robot hands and mechanical grippers. Based on the bendable lamellar structures of the gecko, annular wedge adhesive surfaces that stick to the finger surfaces of dexterous robot hands to improve their load capacity are proposed and fabricated via a suitable combined processing method of ultraprecision machining and replica molding. The greater the width, the higher the replication integrity, and when the minimum width is 20 μm, the replication error is less than 5.5% due to the superior processing performance of the nickel–phosphorus (Ni–P) plating of the master mold. The fabricated annular wedge structures with an optimized width of 20 μm not only exhibit a strong friction force of up to 35.48 mN under a preload of 20 mN in the GCr15/poly(dimethylsiloxane) (PDMS) friction pair but also demonstrate an obviously improved anisotropic friction characteristic of up to λ = 1.36, as the molecular force exhibits a stronger increase as compared to the decrease of the mechanical force of the structure with a small width.

中文翻译：

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壁虎启发的仿生表面，具有超精密加工和仿品成型的环形楔形结构

当前关于壁虎启发的干胶的研究集中在具有不同末端形状（例如扁平，球形，蘑菇形和铲形尖端）的微柱阵列上。相应的处理方法主要是化学方法，包括光刻，蚀刻和沉积，不仅复杂，昂贵且对环境不利，而且不能完全确保微结构的完整性或性能稳定性。本研究证明了一种高精度，高效率和绿色环保的制造壁虎风格表面的方法，该方法可以促进其在灵巧的机器人手和机械抓手中的应用。基于壁虎的可弯曲层状结构，提出并通过超精密加工和仿制成型的适当组合加工方法，制造并制造了环形楔形粘合剂表面，该表面粘附在灵巧的机器人手的手指表面上以提高其负载能力。宽度越大，复制完整性越高，并且当最小宽度为20μm时，由于母模的镍-磷（Ni-P）镀层具有卓越的加工性能，复制误差小于5.5％。所制造的最佳宽度为20μm的环形楔形结构不仅在GCr15 /聚二甲基硅氧烷（PDMS）摩擦对中的预紧力为20 mN时表现出高达35.48 mN的强大摩擦力，而且还显示出各向异性的明显改善摩擦特性高达λ= 1.36，