Fabrication and Analysis of Reversible Interlocking System between Multiscale Line Arrays

Abstract

Inspired from microstructure-based reversible fastening mechanisms in biological system, a number of researches have been conducted to elucidate the principle of adhesion and to mimic its function. Structures with high aspect ratio have been desirably used to maximize van der Waals force, though the weakness of the structures has been one of the major huddles for practical use. Here, instead of high aspect ratio structures which are vulnerable to mechanical failure, the interlocking between arrays of regularly protruded line structures is introduced to provide remarkable repeatability while maintaining substantial adhesion force. Mechanical interlocking between line arrays made by UV-curable material is mediated by van der Waals interaction when two surfaces are brought into contact. By optimizing the geometry and material, failure-free working condition is established and maximum measured adhesion force is recorded about ~ 29.6 N/cm2 without any degradation in adhesion force during repeatable attachment. To analyze the adhesion characteristics, a theoretical model is established using Timoshenko beam bending theory and van der Waals interaction between two surfaces with nanoscale roughness.