Bio-Inspired Climbing Robots in Wet Environments: Recent Trends in Adhesion Methods and Materials

Abstract

In the case of Wall Climbing Robot (WCR) design, nature has always been one of the biggest inspirations. While WCR designs have been incorporating adhesion techniques inspired by organisms, including reptiles, insects, amphibians and marine invertebrates, most efforts have been focusing mainly on adhesion for dry surfaces. For WCRs to become widely applicable under all environments, given the vast areas of this planet described by high precipitation, the ability to scale vertical surfaces in wet conditions should be considered a design necessity. To this goal, this article focuses on the most commonly adopted adhesion mechanisms, while providing an overview on recent WCR technological advances through the prism of wet adhesion. An extensive outlook is also detailed, including promising research directions yet to be trialed in bio-inspirations and recent material developments, which could further bridge the gap between WCR design and wet adhesion towards all-environment climbing robots.