A group of researchers surprises with a new biomaterial made of chitosan that, instead of weakening with water, increases its resistance by up to 50%.
The discovery, made by specialists from the Institute for Bioengineering of Catalonia (IBEC), thus breaks with one of the most established principles of materials engineering.
Moreover, it opens a concrete path to replace the use of conventional plastics with biodegradable options.
The biomaterial combines chitosan, a natural polymer derived from chitin found in crustacean shells and fungal waste, with nickel ions incorporated in a controlled manner.
When hydrated, the mechanical resistance surpasses that of common plastics used daily.
How the chitosan-based biomaterial works
The team took as a reference the arthropod cuticle and the role of certain metals in its behavior towards water. By integrating nickel into the chitosan matrix, a dynamic network of weak and reversible bonds is generated.
With the presence of water, the metal ions acquire molecular mobility. This micro-reorganization allows for stress redistribution, impact absorption, and the prevention of brittle fractures.
Thus, the material does not resist the environment: it interacts with it.
The result is, in the words of the IBEC team, “soft at the molecular scale, strong at the macroscopic scale”. This logic, far removed from rigid and inert plastic, proves surprisingly effective.
Waste-free production and its concrete applications
The manufacturing process also incorporates a zero waste scheme. During the first immersion in water, the nickel that is not part of the structure is released, fully recovered, and reused in the next production cycle.
The chitosan biomaterial has already demonstrated its ability to form sheets, watertight containers, and large pieces. The team identified specific sectors where it can replace plastic:
- Agriculture: packaging and coverings exposed to constant humidity.
- Packaging: biodegradable alternative to single-use plastic containers.
- Fishing: utensils and containers that operate in direct contact with water.
- Temporary storage: short-use containers with controlled degradation.
Moreover, the raw material of the chitosan biomaterial does not depend on global supply chains. It can be obtained from local organic waste of all kinds.
This includes agricultural by-products, urban food waste, or fungal biomass.
Although the study focused on the industrial applications of this biomaterial, both chitosan and nickel have approved uses in specific medical contexts.
The IBEC team does not rule out future applications in biomedical coatings resistant to moisture, always under strict evaluations.
Nickel was the first piece that fit, but the team notes that other metals could offer similar properties.
What is relevant, according to the researchers, is not just the chitosan biomaterial itself, but the change in approach: designing materials that interact with their environment instead of isolating from it.
