Tunable and Durable Seawater Adhesives

Gluing things together under water poses a significant challenge. In seawater this is even more difficult due to the salt content, and currently the performance and durability of seawater adhesives is very limited. This is a problem for applications in marine industry such as underwater robotics, underwater repair, and subsea sealants. The SEAD project aims to develop novel environmentally friendly materials that can act as a durable and permanent glue for use in seawater. This can be used for repair of sub-sea structures, attachment of sensors, etc. In addition, we aim to develop reversible adhesion (post-it note effect) for the feet of marine robots and other non-permanent attachments. In order to achieve the desired effect, we will combine knowledge from the mechanisms marine life utilizes to stick to surfaces under water (biomimicking) with advanced chemistry and adhesion physics. We have made a relatively robust flexible hydrogels for the reversible adhesion, and identified and synthesized multiple monomers suitable for the permanent adhesive development.

Sustainable underwater adhesion is a significant challenge for applications in marine industry such as underwater robotics, underwater repair, and subsea sealants. This is especially apparent in seawater with its elevated ion content. Since organisms like mussel and octopus excel in underwater adhesion, synthetic adhesives mimicking mussel-inspired adhesive chemistry or octopus-inspired adhesive structure have been widely reported. However, prior-art adhesive research often studies how material chemistry and surface geometry independently impact the adhesion behavior. There is a substantial knowledge gap regarding how chemical, geometric, and material properties interact to control underwater adhesion. Moreover, the performance and durability of the reported adhesives are severely limited under harsh environments. The SEAD project aims to develop novel adhesive strategies that tailor tunable and durable adhesives for target applications in seawater by integrating the knowledge from biomimetics, polymer chemistry and adhesion mechanics into a cooperative framework via theoretical calculation, advanced simulation and pathbreaking experiments. Unlike previous work, that often use mussel-inspired catechol-based compounds for underwater adhesion, this project will explore the potential of plant-inspired pyrogallol-based compounds as adhesion anchoring sites. This is expected to hinder the adverse oxidation of hydroxyl groups in catechol, and thereby improve the performance and durability of adhesives in seawater. The research will accelerate the fundamentals of seawater adhesion to transform the developed adhesives for different substrates in harsh environments. The gained knowledge on tunable and durable seawater adhesion will stimulate the advancement of subsea structure design and provide new paradigms in adhesive applications, facilitating the development of a sustainable ocean economy.