Stress Simulation of Polydimethylsiloxane-Coated Fiber Bragg Grating Bend Sensor

Fiber Bragg Grating (FBG) has garnered significant interest in the field of bend sensors. However, one major drawback of the FBG is its inherent structure fragility due to structural deformation. Hence, this paper seeks to.remedy this problem by presenting a stress simulation of a polydimethylsiloxane (PDMS)-coated FBG by utilizing Ansys Workbench 2023 R1 software. The FBG’s design optimization was performed by varying the PDMS thickness from 0 mm to 2 mm. To evaluate the stress performance of the FBG, the coated and uncoated FBGs were compared with those subjected to an additional force of 0.010 N. The simulation results revealed that increasing the PDMS thickness slightly reduces structural deformation but significantly improves the maximum combined stress. The uncoated FBG exhibited the largest deformation of 0.28926 mm and the highest maximum combined stress of 73.309 MPa, whereas the smallest deformation of 0.27419 mm and the lowest maximum combined stress of 61.885 MPa were achieved with a PDMS thickness of 2 mm. Therefore, the minimal changes in deformation, up to 5.21% of the PDMS-coated FBG compared with the uncoated FBG, make it a suitable candidate to sustain the curvature structure of the FBG. Meanwhile, the maximum combined stress of the PDMS-coated FBG was 15.58% higher than that of the uncoated FBG, proving that the presence of PDMS improves the mechanical performance of the FBG by providing enhanced physical robustness, thereby showcasing its potential as a new bend sensor.