A New Concept for an Adhesive Material Inspired by Clingfish Sucker Nanofilaments

Underwater adhesive materials are in high demand in various fields, and fish species with sucker disks have attracted attention due to their superior performance and interesting structures. The clingfish, in particular, is widely known for using hierarchical sucker disk structures to demonstrate rapid and strong adhesion to rocky surfaces under strong currents. We examined the combination of nanofilaments and mucus in the clingfish sucker disk. Nanofilaments reinforce mucus adhesion force by reducing the compliance without affecting the contact area. We prepared structures from hard polymers and soft polydimethylsiloxane (PDMS) that mimicked clingfish sucker nanofilaments and mucus, with these biomimetic structures showing significant adhesion force underwater. Furthermore, the hardness and length of the nanofilaments and Young's modulus and thickness of the mucus-mimicking PDMS layer had critical effects on the adhesion force. According to the results, clingfish nanofilaments act as hard bracing for the soft mucus, and the structural combination of the conflicting characteristics of hardness and softness, thus achieved, is crucial for strong adhesion.

Automated summary

This article analyzes the effect of the combination of nanofilaments and mucus on the adhesion force of clingfish sucker disk. The study found that nanofilaments can enhance the adhesion force of mucus, and the hardness and length of the nanofilaments and the Young's modulus and thickness of the mucus-mimicking layer also have significant effects on the adhesion force. The structural combination of hardness and softness in the clingfish sucker disk is crucial for achieving strong adhesion.