Zhao Donghao, Cartier Alex, Narita Tetsuharu, Lechenault Frederic, Creton Costantino, Ciccotti Matteo
Laboratoire de Sciences et Ingénierie de la Matière Molle, ESPCI Paris, CNRS, PSL University, Paris, France.
Laboratoire de Physique de l'École normale supérieure, ENS, CNRS, PSL University, Sorbonne Université, Université Paris Cité, Paris, France.
Nat Commun. 2025 Apr 3;16(1):3203. doi: 10.1038/s41467-025-58483-1.
Tearing tough soft solids such as rubbers, leather or meat is much harder than cutting them with a sharp blade. To understand why, we use samples labeled with mechanically sensitive fluorophores to investigate cutting and fracture behavior in PDMS elastomers and quantify the extent of bond scission resulting from cutting pre-stretched samples. Our findings reveal that stretch-induced cracks produce significant deformation, bond scission and blunting near the crack tip, requiring more energy to propagate. In contrast, using blades reduces the amount of stretching and blunting required for crack propagation, resulting in a lower fracture energy. The measured linear correlation between fracture energy and the areal density of broken chains clarifies the relationship between pre-stretching, blunting, and molecular damage. These multi-scale insights demonstrate the key differences between fracture and cutting mechanics of soft materials, allowing to optimize engineering applications, such as rubber and food processing, energy-efficient recycling, biomedical and surgical devices, protective equipment and sports gear.
撕裂诸如橡胶、皮革或肉类等坚韧的软固体比用锋利刀片切割它们要困难得多。为了理解其中的原因，我们使用标记有机械敏感荧光团的样本，来研究聚二甲基硅氧烷（PDMS）弹性体中的切割和断裂行为，并量化切割预拉伸样本所导致的键断裂程度。我们的研究结果表明，拉伸诱导的裂纹在裂纹尖端附近会产生显著的变形、键断裂和钝圆，裂纹扩展需要更多能量。相比之下，使用刀片可减少裂纹扩展所需的拉伸和钝圆量，从而降低断裂能。测得的断裂能与断裂链的面密度之间的线性相关性，阐明了预拉伸、钝圆和分子损伤之间的关系。这些多尺度的见解揭示了软材料断裂和切割力学之间的关键差异，有助于优化工程应用，如橡胶和食品加工、节能回收、生物医学和外科器械、防护装备及运动器材等。
