Ultra-stick Hydrogels: Ten Times Stronger Than Other Water-based Adhesives

The rubber ducks that remained attached to coastal rocks for over a year demonstrate the durability of this innovative sticky material. This adhesive has potential applications in deep-sea robotics, repair tasks, and as a surgical adhesive in medical contexts.

“We have created an ultra-sticky hydrogel that performs exceptionally well even when submerged,” says Hailong Fan from Shenzhen University, China. This hydrogel is a soft and flexible material.

Subsequently, at Hokkaido University in Japan, Fan and his team examined 24,000 sticky protein sequences from various organisms to pinpoint the most adhesive amino acid combination, the foundational components of proteins. They leveraged this knowledge to design 180 unique adhesive hydrogels and utilized artificial intelligence models trained on hydrogel properties to optimize formulas for enhanced adhesive agents.

This method allowed the researchers to create a novel class of adaptable, highly sticky hydrogels. According to Fan, this material can adhere to surfaces even after being repeatedly halted and re-stocked or submerged in seawater. Under these circumstances, it surpassed an adhesive strength of 1 megapascal in water, which is about ten times stronger than most soft, sticky materials.

The study indicates that it “illustrates a paradigm shift in the design of high-performance soft materials.” Zhao Qin at Syracuse University in New York commended the team’s efforts in unraveling the adhesive mechanisms of natural proteins and utilizing them in new materials.

The most playful showcase of the hydrogel’s adhesion involved leaving a yellow rubber duck stuck to wave-battered rocks along the shore. In a more pragmatic test, the hydrogel promptly sealed a leaking water pipe. This hints at its potential for repairing underwater structures and improving the durability of flexible electronics and robotics.

This material is also biocompatible, as confirmed by implanting it under the skin of mice, which opens up avenues for biomedical uses such as implants and surgical adhesives.

The impressive adhesiveness of these hydrogels is notable, but it’s important to consider that the material needs to maintain sufficient thickness to function effectively. Researchers hope to test it beyond ideal lab environments, especially in real-world scenarios with rough, contaminated, or moving surfaces.

The team has filed for patents concerning this novel material through Hokkaido University.