自我修复材料即将问世

You've seen it in movies: the human-like, robot assassin（刺客） quickly regenerates² its structure after being damaged beyond recognition. This "Terminator" scenario³ is becoming less far-fetched as recent advances in structural⁴ health monitoring systems have led to a variety of ways to identify damage to a structural system. Now, in the Journal of Applied⁵ Physics, researchers at Arizona State University have created a material that may be able to not only sense damage in structural materials, such as cracking in a fiber-reinforced composite（复合材料，合成物） , but to even heal it. The aim of developing "autonomous⁶ adaptive structures" is to mimic⁷ the ability of biological systems such as bone to sense the presence of damage, halt its progression, and regenerate¹ itself.

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The novel autonomous material developed by Henry Sodano and colleagues uses "shape-memory" polymers（聚合物） with an embedded⁸ fiber-optic network that functions as both the damage detection sensor⁹ and thermal¹⁰ stimulus¹¹ delivery system to produce a response that mimics¹² the advanced sensory¹³ and healing traits shown in biological systems. An infrared¹⁴ laser transmits light through the fiber-optic system to locally heat the material, stimulating¹⁵ the toughening and healing mechanisms¹⁶.

The material system is capable of increasing the toughness of a specimen¹⁷ by 11 times. After toughening the specimen, the crack can be closed using the shape-memory effect to recover an unprecedented¹⁸ 96 percent of the object's original strength. In fact, after the crack is closed, the new material is nearly five times as tough as the original specimen, even though it has been strained past its original failure strain point by a factor of four. The material and healing process can be applied while the structure is in operation, which has not been possible with existing healing techniques. #