Bio-inspired reversible underwater adhesive

Abstract

The design of smart surfaces with switchable adhesive properties in a wet environment has remained a challenge in adhesion science and materials engineering. Despite intense demands in various industrial applications and exciting progress in mimicking the remarkable wet adhesion through the delicate control of catechol chemistry, polyelectrolyte complex, and supramolecular architectures, the full recapitulation of nature’s dynamic function is limited. Here, we show a facile approach to synthesize bioinspired adhesive, which entails the reversible, tunable, and fast regulation of the wet adhesion on diverse surfaces. The smart wet adhesive takes advantage of the host–guest molecular interaction and the adhesive nature of catechol chemistry, as well as the responsive polymer, allowing for screening and activation of the interfacial interaction simply by a local temperature trigger in an on-demand manner. Our work opens up an avenue for the rational design of bioinspired adhesives with performances even beyond nature.

Macroscopic Supramolecular Assembly through Electrostatic Interactions Based on a Flexible Spacing Coating

“…As summarized in Figure b, the interactive force can further increase by almost fivefold with the increased interaction time to 10 min, during which the growing rate of the forces gradually slows down. This result indicates the time‐consuming reconfiguration process of the polyelectrolytes in the MSA process and also corresponds well with the results of most reports that long time pressing of rigid substrates such as silicon wafers can achieve adhesion.…”

“…The binding strength between these interactive pairs has been in situ quantified to support the observed MSA behaviors. We anticipate that the extension of electrostatic‐interaction‐driven MSA of rigid materials can promote the wide applications of MSA in the construction of 3D ordered structures as tissue scaffolds, rapid underwater adhesion, etc.…”

Switchable Adhesives for Multifunctional Interfaces

“…[64] They found no measurable adhesion between the silicon nitride tip and a swollen PNIPAm brush at room temperature, but measured an ≈10 nN peak adhesion force at 40 °C. [53,57] Regardless, the performance and limitations are representative of the basic physics of the materials. Further detail was added by the Surface Forces Apparatus measurements of adhesion between two grafted layers of PNIPAm conducted by Malham and Bureau.…”

Self‐Hydrophobization in a Dynamic Hydrogel for Creating Nonspecific Repeatable Underwater Adhesion

“…The hydration overlayer either prevents the formation of molecular bridges between the adhesive and applied surfaces, or induces swelling stress that leads to the failure of adhesion . To overcome these challenges, underwater adhesive hydrogels based on proteins, synthetic polymers, and biomolecules (i.e., catechol derivatives), have recently been developed recently. These materials can undergo in situ gelation/crosslinking reactions at the interfaces, or form specific interactions with some functional substrates, to generate strong underwater adhesion.…”