Researchers at the Institute for Bioengineering of Catalonia (IBEC) have developed a novel biomaterial that defies a fundamental weakness of most natural materials: it gets stronger when exposed to water. This innovation, created by combining a common organic molecule with nickel, presents a promising and sustainable alternative to the pervasive problem of plastic pollution.
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Despite their significant negative impacts on health and the environment, plastics remain ubiquitous due to their versatility, durability, and, crucially, their water resistance. Efforts to replace them with biomaterials have often been hampered because most biological substances weaken and degrade in wet conditions. Now, a team at IBEC has engineered a material that not only withstands water but uses it to increase its strength by up to 50%.
The findings, published in the prestigious journal Nature Communications, detail a new paradigm in material science. “Instead of looking for a material that nature cannot attack or degrade, like plastics, we have created a material that benefits from the environment,” explained Javier G. Fernández, principal investigator at IBEC’s Biointegrated Materials and Engineering group and the study’s leader.
Inspired by Nature’s Engineering
The breakthrough was inspired by a fortuitous observation of sandworm fangs. Researchers noticed that when zinc was removed from the fangs, they became soft and susceptible to hydration. This suggested that metals could play a key role in how natural materials interact with water.
Following this lead, the IBEC team turned to chitosan, a material derived from chitin—the second most abundant organic molecule on Earth after cellulose. Chitin is found in the shells of crustaceans, insects, and fungi. By incorporating nickel, a naturally occurring trace element, into thin films of chitosan derived from shrimp shell waste, they created a material with remarkable properties.
When submerged in water, the material becomes stronger. The researchers explain this is due to a dynamic network of weak, reversible bonds formed by the mobile nickel ions and surrounding water molecules. This network continuously breaks and reforms, allowing the material to absorb mechanical stress and reorganise itself, mimicking the behaviour of natural biological structures.
A Circular and Sustainable Solution
A core principle of the project is to work in harmony with natural cycles. The biomaterial is designed to be fully reintegrated into the environment after use, as the process does not alter the fundamental nature of the chitosan molecule.
The manufacturing process itself is designed to be zero-waste. Any nickel that does not contribute to the material’s structural bonds is recovered and reused for the next batch. Furthermore, the raw material, chitosan, can be sourced locally anywhere on the planet.
“The key is to adapt to local sources, integrating the production of these materials into the local ecosystem using any form of chitosan available in the area,” stated Akshayakumar Kompa, a postdoctoral researcher in Fernández’s group and the study’s first author. He noted that it can be obtained from shrimp shells, urban organic waste, or fungi.
The global abundance of chitin is staggering. According to Fernández’s team, the world produces around 100 billion tonnes of chitin annually, equivalent to 300 years of plastic production. “We can extract it from insects, from fungi, from any crustacean, from organic garbage… That is the beauty of working within the natural system,” he emphasised.
From Lab to Large-Scale Application
The researchers at IBEC, a member of the Barcelona Institute of Science and Technology (BIST), have already demonstrated that the process is scalable, having produced five-metre-high structures and samples several square metres in size. While the current cost is slightly higher than conventional plastic, Fernández is confident it will decrease as the manufacturing process is optimised, particularly since local production eliminates significant transportation costs.
Initial applications are envisioned for agriculture, fishing materials, and packaging, where the need for water-resistant, biodegradable materials is urgent. The material’s ability to form watertight containers like cups also positions it as a potential substitute for certain single-use plastics.
Looking further ahead, since both nickel and chitosan are individually approved by the FDA for specific medical uses, the biomaterial could find applications in the healthcare sector or as a waterproof coating for other biomaterials.
Fernández concluded that the innovation challenges long-held assumptions about material technology. “One of the great mistakes made so far is assuming that the technology associated with plastic was the pinnacle,” he said. “What we have developed at IBEC surpasses, in many cases, that plastic technology; for example, 3D printing is faster with these biomaterials.”
