Researchers Create Ultra-Sticky Underwater Hydrogels Using AI

Researchers at Hokkaido University in Japan have developed an innovative hydrogel material that exhibits exceptional adhesion in underwater environments. This breakthrough comes from integrating artificial intelligence (AI) with data mining techniques, addressing the significant challenges in designing soft materials that require unique configurations of polymeric building blocks.

Hydrogels are soft, permeable materials formed by interlinked polymer networks that trap water within their structure. Their versatility allows for a wide range of applications; however, designing hydrogels that can effectively perform specific functions remains complex. The properties of these materials are influenced by various factors, including molecular arrangement and intermolecular interactions such as van der Waals forces and hydrogen bonds.

Creating adhesives that function well in wet conditions presents additional challenges. Hydrogels tend to swell in the presence of water, complicating their design for underwater adhesion. To overcome this, the research team mined data from the National Center for Biotechnology Information (NCBI) Protein database, which houses amino acid sequences responsible for adhesion in various biological organisms, including bacteria and eukaryotes.

According to Hailong Fan, a co-lead author of the study published in the journal Nature, the team aimed to explore new design rules by systematically analyzing the entire protein database. “We were inspired by nature’s adhesive proteins, but we wanted to go beyond mimicking a few examples,” he explained. The researchers synthesized 180 bioinspired hydrogels, each showcasing adhesive properties that surpassed existing options.

Using machine learning, the team created hydrogels that achieved record-breaking underwater adhesive strengths exceeding 1 MPa. This marks a significant improvement over previous materials, demonstrating strong and repeatable adhesion across various surfaces in both fresh and saline water. “The key achievement is not just creating a record-breaking underwater adhesive hydrogel but demonstrating a new pathway—moving from biomimetic experience to data-driven, AI-guided material design,” Fan added.

To validate the performance of their top hydrogels, the researchers conducted tests in diverse wet environments. One hydrogel successfully adhered a rubber duck to a rock, remaining intact despite continuous wave impacts over several tide cycles. Another hydrogel effectively sealed a 20 mm hole in a high-pressure water-filled pipe, maintaining its integrity for five months. The third hydrogel was tested for biocompatibility by placing it under the skin of mice.

The implications of this research are vast. The strong adhesive properties of these hydrogels hold potential applications in fields such as biomedical engineering, including prosthetic coatings and wearable biosensors, as well as in marine farming and deep-sea exploration. The researchers also believe that this data-driven approach can be adapted for designing other functional soft materials.

Looking ahead, Fan indicated that the team plans to delve deeper into the molecular mechanisms of these adhesives. “Our next step is to study the molecular mechanisms behind these adhesives in more depth, and to expand this data-driven design strategy to other soft materials, such as self-healing and biomedical hydrogels,” he stated. This research not only opens new avenues for material design but also exemplifies the transformative role of AI in engineering.