When cracks form inside the composite material, the fiber layer and polymer matrix tend to separate, severely compromising the material's structural integrity and ultimately leading to component failure. Currently, the design lifespan of traditional FRP composites is only 15-40 years, requiring substantial manpower and resources for regular inspections and maintenance. The replacement of damaged components also generates significant industrial waste, driving up operational costs in the industry.

Recently, a research team from North Carolina State University (NC State) in the United States has developed a new type of self-healing composite material, which not only greatly improves its anti delamination ability, but also achieves over 1000 self-healing cycles. It can extend the service life of traditional composite components from decades to hundreds of years, bringing revolutionary breakthroughs to the high-end application of composite materials such as carbon fiber. The relevant research results were published in the Proceedings of the National Academy of Sciences (PNAS) in the United States.

●Core innovation: Two major designs endow materials with the ability to self repair

1.The research team for 3D printing thermoplastic healing agents and strengthening interlayer performance prepared thermoplastic healing agents on the surface of fiber-reinforced materials through 3D printing technology, forming polymer patterned interlayers. This design directly increases the delamination resistance of composite materials by 2-4 times, significantly reducing the probability of material cracking.

2.Embedding a carbon based heating layer, an ultra-thin carbon based heating layer is integrated inside the thermal triggered repair material. After being powered on, it can quickly heat up, causing the thermoplastic healing agent to melt and flow into cracks and micro damage areas, re bonding the layered interface, and accurately restoring the structural properties of the material. This thermal repair method responds quickly and can be triggered as needed based on the damage situation.

●Experimental verification: After 40 days of thousands of cycles of repair, the performance degradation is extremely slow

To verify the long-term repair performance of the material, the research team built an automated testing system and conducted rigorous damage repair cycle experiments: applying tensile force to the composite material to create a 50mm long interlayer delamination damage, then triggering a heat repair mechanism, and testing its anti delamination bearing capacity again after repair. This process was repeated 1000 times continuously, taking a total of 40 days, and the number of repairs increased by an order of magnitude compared to the team's previous records.

The experimental results show that the initial fracture resistance of this self-healing composite material is significantly better than that of unmodified traditional composite materials; In the first 500 cycles, its anti cracking ability consistently maintains a leading level; Even if the interlayer toughness decreases after multiple repairs, the decay rate is extremely slow. The data shows that the initial repair efficiency of the material can reach 175% of that of ordinary composite materials, and even after multiple cycles, it can still maintain over 60% of its fracture resistance.

n practice, this means users can rely on a given structural component, such as a wind turbine blade, for an extended period without worrying about failure. The printed thermoplastic also enhances inherent fracture resistance by up to 500%.

The new technology has another advantage. If this internal heating element is integrated into the aircraft wings, airlines can stop using chemical agents to remove ice from the wings when the plane is on the ground, as well as de-ice during flight.