Perspectives on Mussel-Inspired Wet Adhesion

Abstract

Nature employs sophisticated control of a structure's properties at multiple length scales to achieve its wet adhesion. However, the translation of such structures has very often been missing in biomimetic adhesives; in turn, their performance is significantly limited as compared to that of biological adhesion, e.g., from mussels. In this Perspective, we overview the major breakthroughs in this field, highlighting the recent advances that demonstrate that holistic multiscale translation is essential to biomimetic design. We argue that the multiscale coordination of numerous key elements in the natural adhesive system is essential to replicate the strong, instant, and durable wet adhesion of the marine sessile organism.

Water‐Triggered Hyperbranched Polymer Universal Adhesives: From Strong Underwater Adhesion to Rapid Sealing Hemostasis

“…[9] The commercially available epoxy resins [10] and polyurethanes [11] are reported to demonstrate strong underwater adhesion, but long time of curing is usually required. [15][16][17] The finding of universality of catechol chemistry for wet adhesion has provided a valuable biomimetic source to develop diverse adhesives for use in aqueous environments. [5,12] In addition, electrostatic and hydrophobic interactions were also proved to contribute to enhanced underwater adhesion, but the adhesion strength was relatively poor.…”

“…[13,14] In nature, many organisms, such as mussels, barnacles, and castle worms, have evolved an unparalleled mechanism to perfectly tackle the underwater adhesion problem. [15][16][17] The finding of universality of catechol chemistry for wet adhesion has provided a valuable biomimetic source to develop diverse adhesives for use in aqueous environments. However, several problems, such as the complexity of administration, release of harmful organic solvents, [18,19] long-term curing, [2] need for oxidant addition, [20,21] and low adhesion strength, [18,22] may hamper the actual applications of these bioinspired adhesives.…”

Tough Adhesion of Nucleobase‐Tackifed Gels in Diverse Solvents

“…The triethylamine salt was removed through repeated frozen and crystallized of solution, followed by acrylated adenine (Aa) was precipitated by diethyl ether solution. The chemical structure was confirmed by 1 H-NMR (400 MHz, DMSO-d 6 , δ ppm) and 13 Preparation of Adhesive Gels: 2 g acrylic acid, 2 g methoxyethyl acrylate, 0.2 g Aa, and 0.04 g KPS were added into solution consisting of DMSO (5 mL) and water (5 mL). The solution was continuously stirred until homogeneous and poured into a cylindrical Teflon reactor (50 mm diameter).…”

“…Yuk et al presented a chemical anchor strategy to fabricate a tough interface between hydrogels and nonporous solid substrate surfaces. [11] Moreover, underwater adhesion also achieved a prominent progress based on various nature-inspired strategies, including 3,4-dihydroxyphenyl-L-alanine (DOPA)-modified adhesives, [12,13] structure-inspired adhesives, [14][15][16] and biomimetic protein adhesives. [10] Gao et al demonstrated a photodetachable adhesion principle to achieve strong adhesion and easy on-demand detachment for various materials.…”

“…[10] Gao et al demonstrated a photodetachable adhesion principle to achieve strong adhesion and easy on-demand detachment for various materials. [11] Moreover, underwater adhesion also achieved a prominent progress based on various nature-inspired strategies, including 3,4-dihydroxyphenyl-L-alanine (DOPA)-modified adhesives, [12,13] structure-inspired adhesives, [14][15][16] and biomimetic protein adhesives. [17][18][19] However, most works only focused on the adhesion behavior in air and/or water, the technology of strong adhesion and acrylate adenine were utilized to fabricate adhesive gels via the radical polymerization in the mixed solvents of water and DMSO.…”