Tree-frog-inspired osmocapillary adhesive bonding to diverse substrates

Abstract: The performance of conventional pressure-sensitive adhesives (PSA) critically relies on the wetting of the adhesive over the substrate. When the wetting is hindered by low surface-energy substrates or the presence of interfacial liquids, the adhesion is greatly compromised. Here, inspired by tree frogs that secrete mucus with surfactants to achieve good wetting over diverse dry and wet substrates, we explore a novel mechanism, osmocapillary adhesion, to use interfacial liquid modified by surfactant to wet diverse substrates and achieve robust reversible adhesion. We show that osmocapillary adhesives greatly outperform conventional PSAs over low-energy, moist, oily, and greasy substrates while achieving similar performance on high-energy surfaces.