Long-period fiber grating embedded in polymer structure for deformation monitoring

We propose a strain sensor based on a long-period fiber grating (LPFG) packaged in a 3D-printed structure made of polymer material. The proposed sensing structure was fabricated using a commercially available 3D printer by embedding a bare LPFG sensor inside the polymer material during the printing process. The raw material used for the fabrication of the polymer structure was Polylactic Acid (PLA). We experimentally investigated the strain-dependent spectral response of the produced sensor by observing the transmitted spectral profile. Finally, the results showed that a linear strain sensitivity of - 4.6 pm/mu epsilon with the range of 0-1000 mu epsilon was achieved, therefore indicating that the proposed sensing device is suitable for strain deformation measurement.