Modeling Fabrication and Testing of Artificial Gecko Adhesion using Multi Layer Fbrillar Structure

Abstract- The idea of designing a micro level artificial gecko adhesive structure isinspired from ability of geckos to climb any surface. Gecko can climb any rough or smooth surface because of its hierarchical structure present on feet which functions as a smart adhesive [1]. The key parameter that affects gecko adhesion are pattern periodicity of a synthetic setae, hierarchical structure, length, diameter, angle, size, stiffness of end tips and flexibility of a base [2]. The design and fabrication of number of single and multi-level hierarchical pattern were performed. CO2 LASER cutting machine having power of 60 W is used to manufacture moulds. The mould is fabricated from methyl methacrylate sheets of different thickness 3 mm to 10 mm. Liquid silicone polymer PDMS is used as a cast material. Various patterns having dimensionsupto200 micrometer with different tip shapes and geometries were fabricated. For single level patterns like dense pattern, mushroom shape pattern and wedge pattern (lamellar structure) were fabricated. Attempts were made to design and fabricate Multi-level hierarchical structure patterns that mimics gecko like foot structure. These micro level artificial gecko structure have large scope of applications such as climbing robots, non-sticky adhesion tapes, military surveillance and even medical applications.

Keywords- LASER cutting, artificial gecko, Adhesion, Setae, Spatula.

INTRODUCTION number of researchers studied gecko adhesion using various theoretical and experimental techniques to understand frictional adhesion properties and mechanism of gecko feet, hairs and setae in order to mimic the gecko feet as strong, non-sticky and self-cleaning adhesion. The conventional adhesives like Pressure Sensitive Adhesives (PSAs) are soft and sticky to make continuous contact with the surface. PSAs have major effects of fouling, degrade and accidentally adhere any surface when not required. Whereas compared to PSAs artificial gecko adhesives are non-tacky, self-cleaning, easy to attach and detach. The ability of geckos to climb any rough or smooth surface at any angle inspired researchers to develop non-tacky pads for vertical climbing robots and many such applications.
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