Over the past few decades, optical waveguides have been increasingly used in wearable/implantable devices for on-body sensing. However, conventional optical waveguides are stiff, rigid, and brittle. A mismatch between conventional optical waveguides and complex biointerfaces makes wearable/implantable devices uncomfortable to wear and potentially unsafe. Soft and stretchable polymer optical waveguides not only inherit many advantages of conventional optical waveguides (e.g., immunity to electromagnetic interference and without electrical hazards) but also provide a new perspective for solving the mismatch between conventional optical waveguides and complex biointerfaces, which is essential for the development of light-based wearable/implantable sensors. In this review, polymer optical waveguides’ unique properties, including flexibility, biocompatibility and biodegradability, porosity, and stimulus responsiveness, and their applications in the wearable/implantable field in recent years are summarized. Then, we briefly discuss the current challenges of high optical loss, unstable signal transmission, low manufacturing efficiency, and difficulty in deployment during implantation of flexible polymer optical waveguides, and propose some possible solutions to these problems.

中文翻译：

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柔软可伸缩的光波导：复杂生物接口处的光传输和操纵，创建了用于人体感应的独特窗口

在过去的几十年中，光波导已越来越多地用于可穿戴/可植入设备中以进行人体感应。然而，常规的光波导是刚性的，刚性的和脆性的。传统的光波导和复杂的生物界面之间的不匹配使得可穿戴/可植入设备不舒服且可能不安全。柔软且可拉伸的聚合物光波导不仅继承了常规光波导的许多优点（例如，抗电磁干扰和无电气危害），而且还为解决常规光波导与复杂生物界面之间的不匹配提供了新的视角，这对于光波导是至关重要的。基于光的可穿戴/可植入传感器的开发。在这篇评论中，聚合物光波导的独特性能包括柔韧性，总结了近年来的生物相容性和生物降解性，孔隙率和刺激响应性及其在可穿戴/可植入领域中的应用。然后，我们简要讨论了当前的挑战，即光损耗高，信号传输不稳定，制造效率低以及在柔性聚合物光波导注入过程中难以部署，并提出了解决这些问题的可能方案。