Highly flexible and self-adaptive dry adhesive end-effectors for precision robotics

Many research groups have studied biomimetic functional surfaces for practical applications. Dry adhesives inspired by the gecko foot consist of hierarchical and numerous micro/nano hairs and can achieve pull-off strengths for vertical and shear adhesion of up to 20 N cm^-2. However, when detachment of the nearly dry adhesive is carried out by peeling, the pull-off strength of the dry adhesive in the tilted state is remarkably reduced. In this study, an enhanced pull-off strength dry adhesive in the tilted state was fabricated by using a strategy that reduces the restoring force from the bending moment. An experiment with various column-type dry adhesives was implemented to find the relation between the pull-off strength in the tilted state and the bending resistance of the dry adhesive. The feasibility of using a dry adhesive in the tilted state was observed through a glass-lifting experiment. This strategy could be widely utilized in many practical applications, such as robotics.