Japan team develops “highest-performing” underwater adhesive

Hokkaido, Japan – Researchers at Hokkaido University have developed the strongest ever underwater-adhesive hydrogels, the university has announced.

Using a data mining and machine learning approach, the team led by professors Gong, Takigawa, and Fan (see caption) at the university’s WPI-ICReDD research lab developed hyrogels with adhesive strengths (Fa) exceeding 1 MPa.

The gels’ strength was “both instant and repeatable and they are functional across various surfaces under variable levels of salinity from pure water to seawater,” said the 7 Aug release.

If cut to the size of a 2.5 x 2.5 cm postage stamp, the adhesives could theoretically support an adult human weighing around 63 kg, Hokkaido University added.

The hydrogels are based on polymer networks derived from adhesive proteins found in archaea, bacteria, eukaryotes, and viruses, according to the release.

Despite the diversity across these organisms, it noted, these proteins share common sequence patterns that endow adhesion in wet environments.

Around 25,000 adhesive-protein datasets, collected from Japan’s National Center for Biotechnology Information (NCBI) protein database, were data mined for relevant amino acid sequences important for underwater adhesion.

The researchers replicated these sequences into polymer networks and synthesised 180 hydrogels—each containing unique polymer networks.

Data compiled from studying these hydrogels was analysed with machine learning which further extrapolated the most significant polymer sequences.

The original 180 gels synthesized from data mining “demonstrated adhesive qualities greater than gels previously reported in the literature,” stated the university.

However, it added, “the gels inspired by machine learning were more incredible, exceeding the highly desired qualities mentioned above.”

Pictured (l to r): Hailong Fan (front row), Jian Ping Gong, and Hongguang Liao from the research team show hydrogels fixed between ceramic, glass and titanium plates supporting 1kg weights in normal saline for over a year.

Photo credit: WPI-ICReDD