Effects of loading and unloading control parameters on adhesive performance for biomimetic controllable adhesive with wedge-shaped microstructures

Abstract

The adhesive performance of biomimetic controllable adhesive based on wedge-shaped microstructures is affected by some relevant control parameters in the process of loading and unloading. An appropriate selection of these control parameters is of great significance for its effective application. However, little research has concentratively and comprehensively explored these control parameters. In order to make up for the shortcoming, this study systematically explored the macroscopic adhesive performance of the self-developed wedge-shaped microstructures under different loading and unloading control parameters. The results show that preloading depth and tangential dragging distance have a positive effect on the adhesive performance, while preloading angle and peeling angle have a negative effect on the adhesive performance. Specifically, a low preloading angle can weaken the normal preloading force under the same preloading depth, thereby improving the preloading benefit; the application of tangential dragging distance can also induce the normal preloading force generated in the preloading stage to change the adhesion, so as to stimulate more adhesion. Based on the interactive analysis of these control parameters, it can be sure that applying a moderate normal preloading force and a larger tangential dragging distance to the wedge-shaped microstructures at low preloading angle not only makes the wedge-shaped microstructures possess better adhesive capacity, but also can obtain a good preloading benefit. In addition, the promotion effect of a low peeling angle on the adhesive performance also implies that a higher peeling angle should be used to realize the easy detachment of the adhesive interface. The first concentrative and comprehensive investigation of the relevant control parameters of wedge-shaped microstructures lays the foundation for designing a climbing robot or adhesive gripper based on the wedge-shaped microstructures, and also provides guidance for formulating the corresponding control strategies.