A new fiber-reinforced composite developed by researchers at North Carolina State University could dramatically extend the lifespan of machines, potentially allowing critical structures to last for centuries. The breakthrough material is designed to repeatedly heal internal damage, reducing the need for costly repairs or replacements in industries ranging from aerospace to renewable energy.
The research, detailed in a paper published in the Proceedings of the National Academy of Sciences, describes a composite capable of repairing interlaminar cracks more than a thousand times through an automated heating process, according to NC State University. The team’s work focuses on strengthening fiber-reinforced polymer composites, commonly used in vehicles, wind turbines, aircraft, and structural components.
Traditional fiber-reinforced polymers are valued for being lightweight yet strong, but they are vulnerable to delamination, where layers of fibers separate from the surrounding polymer matrix. Over time, those internal cracks compromise structural integrity. The new composite addresses this weakness with two key innovations.
First, researchers incorporated a thermoplastic healing layer that is 3D-printed between fiber reinforcements. This interlayer significantly increases resistance to cracking, reportedly doubling or even quadrupling toughness compared to standard composites. Second, they embedded carbon-based layers that generate heat when electrified. When activated, the heat melts portions of the thermoplastic material, allowing it to flow into cracks and bond separated layers back together.
3D-printed thermoplastic healing agent (blue overlay) on glass-fiber reinforcement (left); infrared thermograph during in-situ self-healing of a fractured fiber-composite (middle); 3D-printed healing agent (blue) on carbon fiber reinforcement (right) Jason Patrick, NC State University
Testing demonstrated impressive durability. In automated experiments, the team repeatedly induced five-centimeter delaminations and triggered self-healing over a thousand cycles within 40 days. The composite maintained performance well beyond conventional materials, which typically degrade after decades of service.
Researchers estimate that if the material required seasonal healing, it could remain functional for around 125 years. If healing were needed only annually, lifespan projections could extend to several centuries. Even after repeated healing cycles, the material’s interlaminar toughness declines gradually rather than sharply.
The implications are substantial. Longer-lasting composites could reduce energy consumption, waste, and maintenance costs across multiple industries. For remote or inaccessible applications such as wind farms, aircraft components, or deep-space probes, the ability to self-repair could eliminate the logistical challenges of replacement parts.
With patents filed and licensing underway through a university-affiliated company, the technology may soon move from laboratory testing to commercial deployment. If scaled successfully, machines built with these composites could outlive the generations that designed them.