Sea cucumber tentacle-inspired underwater granular adhesion

<h2>Summary</h2> Effective underwater granule manipulation is essential for various marine applications, yet it remains challenging due to the intricate behaviors of granules in aquatic environments. Traditional methods, while usable, often lack precision and efficiency. Marine organisms, such as the sea cucumber, have evolved specialized systems for underwater adhesion and granule capture. This study explores the adhesion mechanisms of sea cucumbers with a focus on their specialized tentacles and mucus secretion. We demonstrate that the microstructures of tentacles can significantly increase the adhesion work between the substrate and the mucus, thereby enhancing adhesion and enabling efficient granule manipulation. Our findings deepen the understanding of biological adhesion systems and inspire the development of a sea-cucumber-inspired adhesion device, offering promising solutions to underwater adhesion challenges.