2026-01-14 ノースカロライナ州立大学（NC State）
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). Image credit: Jason Patrick, NC State University.
＜関連情報＞
- https://news.ncsu.edu/2026/01/healing-composite-lasts-centuries/
- https://www.pnas.org/doi/10.1073/pnas.2523447123
- https://tiisys.com/blog/2022/11/01/post-113097/
長期にわたる自己修復：現場自動化により、構造複合材における世紀規模の破壊回復を実現 Self-healing for the long haul: In situ automation delivers century-scale fracture recovery in structural composites
Jack S. Turicek, Zachary J. Phillips, Kalyana B. Nakshatrala, and Jason F. Patrick
Proceedings of the National Academy of Sciences Published:January 9, 2026
DOI:https://doi.org/10.1073/pnas.2523447123
Significance
Delamination damage has long hindered the safety and lifetime of fiber-reinforced polymer composites. This failure mode not only undermines their lightweight mechanical advantage but also amplifies the cost and environmental impact of these modern structural materials, which are inherently challenging to repair/recycle. Here, we innovate self-healing by automating in situ thermal remending to achieve 1,000 delamination heal cycles, an order-of-magnitude greater than prior studies. The life extension unlocks new science where diminishing interfacial chemical reactions and fiber debris accumulation contribute to a gradual, asymptotic decline in fracture recovery that follows a Weibull distribution. Our findings show this self-healing strategy for interlaminar fracture is repeatable on a scale far exceeding typical composite design lifetimes, thus shedding delamination from structural concern.
Abstract
Nature’s structural composites, such as bone and wood, achieve mechanical performance through hierarchical multimaterial design. Though, their real vantage lies in the exceptional ability to repeatedly heal after damage. Synthetic fiber-reinforced polymer (FRP) composites also leverage material hierarchy via fibrous reinforcement encapsulated within a polymer matrix, maximizing stiffness and strength. However, the layered architecture of laminated FRP composites makes them vulnerable to interlaminar delamination—debonding of fibers from the matrix—which significantly compromises structural integrity. Recently, we introduced a self-healing strategy via in situ heating, where soft yet tough thermoplastic inclusions achieve interlaminar fracture recovery via polymer chain re-entanglement, i.e., thermal remending. Here, in our latest embodiment, by automating in situ thermo-mechanical experiments, we achieve an order-of-magnitude enhancement in self-healing repeatability—reaching an unprecedented 1,000 cycles. Healing begins at 175% and slowly declines to 60% of the mode-I fracture resistance of a plain (nonhealing) composite, revealing unique chemo-physical mechanisms that govern this behavior. Both fiber-debris accumulation in the molten poly(ethylene-co-methacrylic acid) (EMAA) healing agent, and waning interfacial chemical reactions between the EMAA and epoxy matrix, contribute. A Weibull distribution capturing this complex fracture recovery predicts an asymptotic healing limit above 40%, suggesting sustained repair is possible. Translating these newfound thermal remending results into real-world context, a modest quarterly self-healing schedule could maintain interlaminar fracture repair of FRP composites for over 125 y—well beyond the typical design life of many modern structures including aircraft and wind turbines. Thus, this latest self-healing paradigm effectively eliminates delamination as a failure mode.
