Light serves a pivotal function in polymer systems, creating a dynamic interplay with the materials. It initiates various photochemical processes such as polymerization, phase transitions, photo-isomerization, photo-ionization, etc, endowing the polymers with diverse functionalities. Concurrently, as these materials undergo the changes, their shape and optical properties evolve, which also change the light behaviors in terms of reflection, refraction, and propagation. This mutual interaction is intricate and can lead to novel phenomena. Understanding this complex coupling is crucial for generating new insights and paves the way for innovative design possibilities. In this study, we combine principles of geometrical optics with a nonlinear chemomechanical theory to investigate the interdependent effects of light direction and polymer behavior, including reactions and deformations. We apply this framework to a photo-responsive hydrogel, comparing simulation with experimental results to extract necessary material properties and using the calibrated model to propose a new design of an optical fiber actuator through simulations. This example highlights how the interaction between light direction and the hydrogel’s photo-induced swelling governs actuation, and we discuss strategies to leverage this understanding for enhanced control and functionality of such devices. Additionally, we employ the model to analyze the growth morphology of the photo-responsive hydrogel, offering a detailed examination of how these interactive forces contribute to the gel’s photo-induced morphological evolution.

中文翻译：

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耦合光响应聚合物和聚合物凝胶的光传播方向和变形的本构模型


光在聚合物系统中发挥着关键作用，与材料产生动态相互作用。它引发聚合、相变、光异构化、光电离等多种光化学过程，赋予聚合物多种功能。同时，随着这些材料发生变化，它们的形状和光学特性也会发生变化，这也会改变光在反射、折射和传播方面的行为。这种相互作用是复杂的，可以导致新奇的现象。理解这种复杂的耦合对于产生新的见解至关重要，并为创新设计的可能性铺平道路。在这项研究中，我们将几何光学原理与非线性化学力学理论相结合，研究光方向和聚合物行为（包括反应和变形）的相互依赖的影响。我们将该框架应用于光响应水凝胶，将模拟与实验结果进行比较，以提取必要的材料特性，并使用校准模型通过模拟提出光纤致动器的新设计。这个例子强调了光方向和水凝胶光致膨胀之间的相互作用如何控制驱动，我们讨论了利用这种理解来增强此类设备的控制和功能的策略。此外，我们利用该模型来分析光响应水凝胶的生长形态，详细检查这些相互作用力如何促进凝胶的光诱导形态演化。