Core–shell dry adhesives for rough surfaces via electrically responsive self-growing strategy

Abstract

Bioinspired dry adhesives have an extraordinary impact in the field of robotic manipulation and locomotion. However, there is a considerable difference between artificial structures and biological ones regarding surface adaptability, especially for rough surfaces. This can be attributed to their distinct structural configuration and forming mechanism. Here, we propose a core–shell adhesive structure that is obtained through a growth strategy, i.e., an electrically responsive self-growing core–shell structure. This growth strategy results in a specific mushroom-shaped structure with a rigid core and a soft shell, which exhibits excellent adhesion on typical target surfaces with roughness ranging from the nanoscale to the microscale up to dozens of micrometers. The proposed adhesion strategy extends dry adhesives from smooth surfaces to rough ones, especially for rough surfaces with roughness up to dozens or hundreds of micrometers, opening an avenue for the development of dry adhesive-based devices and systems.

The design of bioinspired dry adhesives mimicking closely the structure and surface adaptability of biological adhesives is challenging. Here, the authors propose an electrically responsive self-growing core–shell mushroom-shaped structure with a rigid core and a soft shell, which exhibits excellent adhesion on surfaces with roughness ranging from the nanoscale to the microscale.