Lee Sihwan, Cho Yong Eun, Kim Ho-Young, Sun Jeong-Yun
Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea.
Department of Mechanical Engineering, Seoul National University, Seoul, 08826, Republic of Korea.
Small. 2025 Jun;21(23):e2412657. doi: 10.1002/smll.202412657. Epub 2025 Apr 24.
Modulating the mechanical properties of soft materials with light is essential for achieving customizable functionalities. However, existing photo-responsive materials suffer from limited mechanical performance and a restricted tunable range. Here, a photo-tunable elastomer is developed by incorporating a urethane acrylate network with selenosulfide-based dynamic covalent crosslinkers, achieving high tensile strength exceeding 1.2 MPa in their stiff state and variable Young's modulus within a 0.8 MPa range. These crosslinkers undergo selenosulfide photo-metathesis, gradually breaking under ultraviolet light and reforming under visible light, enabling fine control over the modulus, strength, and stretchability of the elastomer. In terms of controllability, the design supports multiple tunable states, which allow for the use of intermediate mechanical properties. Moreover, by modeling the crosslinking density changes with reaction kinetics, modulus variation is predicted as a function of light exposure time. The light-induced modulation facilitates localized mechanical property adjustments, generating transformable multi-material structures and enhancing fracture resistance. Integrating these crosslinkers into different polymer networks provides a strategy for creating various photo-tunable elastomers and gels.
利用光调节软材料的机械性能对于实现可定制功能至关重要。然而，现有的光响应材料存在机械性能有限和可调范围受限的问题。在此，通过将聚氨酯丙烯酸酯网络与基于硒硫化物的动态共价交联剂相结合，开发出一种光可调弹性体，在其刚性状态下实现了超过1.2兆帕的高拉伸强度，并在0.8兆帕范围内实现了可变杨氏模量。这些交联剂经历硒硫化物光复分解反应，在紫外光下逐渐断裂，在可见光下重新形成，从而能够对弹性体的模量、强度和拉伸性进行精细控制。在可控性方面，该设计支持多种可调状态，允许使用中间机械性能。此外，通过用反应动力学对交联密度变化进行建模，可以预测模量变化是曝光时间的函数。光诱导调制有助于局部机械性能调整，生成可变形的多材料结构并增强抗断裂性。将这些交联剂整合到不同的聚合物网络中，为创建各种光可调弹性体和凝胶提供了一种策略。
