Ferrocene 'hooks' (yellow) fit into cucurbituril 'loops' (grey) to hold the two sheets of silicon together © Wiley-VCHSouth Korean scientists have developed a chemical velcro that shows promise as a strong and reversible underwater adhesive. The team suggests it could have many applications that require controllable adhesion in aqueous environments.Previous efforts to create underwater adhesives have mainly focused on biomimetic catechol-based polymers that are secreted by marine organisms, including mussels. However, these require curing agents and work by covalent crosslinking, which results in permanent adhesion.Now, Kimoon Kim and colleagues at Pohang University of Science and Technology, have developed a reversible...