School of Mechanical and Electrical Engineering, Guangzhou University, 510056, Guangzhou, People's Republic of China.
Department of Electronics Engineering, Universidad Técnica Federico Santa María, 2390123, Valparaíso, Chile.
Sci Rep. 2023 Mar 13;13(1):4148. doi: 10.1038/s41598-023-30949-6.
The large development of fibre Bragg gratings (FBGs) over decades has made this kind of structures one of the most mature optical fibre sensing technologies existing today, demonstrating key features for a very wide range of applications. FBG sensors are fragile and must be normally protected for real-field applications, although challenging packaging designs are required to mitigate temperature-strain cross-sensitivity issues. Here, a polydimethylsiloxane (PDMS) packaging with a microarray structure that provides gecko-inspired dry adhesion is proposed for strain-free FBG-based temperature sensing. Besides offering protection, the PDMS packaging with an embedded polyamide capillary damps the mechanical strain transferred to the optical fibre, providing FBG-based temperature sensing with a negligible impact of strain. In addition, the microarray structure imprinted on one surface of the packaging provides gecko-inspired dry adhesion based on van der Waals forces. This feature enables the packaged optical fibre sensor to be attached and detached dynamically to nearly any kind of smooth surface, leaving no residuals in the monitored structure. Experimental results verify a fast and accurate temperature response of the sensor with highly mitigated impact of residual strain. The proposed packaged sensor can be used in application where glue is not allowed nor recommendable to be used.
几十年来，光纤布拉格光栅（FBG）的大量发展使得这种结构成为当今最成熟的光纤传感技术之一，展示了非常广泛的应用的关键特性。FBG 传感器很脆弱，必须在实际应用中进行正常保护，尽管需要具有挑战性的封装设计来减轻温度-应变交叉敏感性问题。在这里，提出了一种具有微阵列结构的聚二甲基硅氧烷（PDMS）封装，为无应变 FBG 基温度传感提供了基于壁虎的干附着。除了提供保护外，嵌入聚酰胺毛细管的 PDMS 封装还可以阻尼传递到光纤的机械应变，为 FBG 基温度传感提供了应变的可忽略影响。此外，封装表面上压印的微阵列结构提供了基于范德华力的基于壁虎的干附着。该特性使封装光纤传感器能够动态地附着和拆卸到几乎任何类型的光滑表面上，在被监测的结构上不会留下任何残留物。实验结果验证了传感器的快速、准确的温度响应，并且应变的残余影响得到了高度缓解。所提出的封装传感器可用于不允许或不建议使用胶水的应用场合。
