Sensitivity and reliability are essential factors for the practical implementation of a wearable sensor. This study explores the possibility of using a hybrid high-resolution Bragg grating sensor for achieving a fast response to dynamic, continuous motion and Bragg signal pattern monitoring measurement. The wavelength shift pattern for real-time monitoring in picometer units was derived by using femtosecond laser Bragg grating processing on an optical wave path with long-period grating. The possibility of measuring the demodulation system’s Bragg signal pattern on the reflection spectrum of the femtosecond laser precision Bragg process and the long-period grating was confirmed. By demonstrating a practical method of wearing the sensor, the application of wearables was also explored. It is possible to present the applicability of sophisticated micro transformation measurement applications in picometer units.

This paper demonstrates the fabrication of radiation-resistant fiber Bragg grating (FBG) sensors using infrared femtosecond laser irradiation. FBG sensors were written inside acrylate-coated fluorine-doped single-mode specialty optical fibers. We detected the Bragg resonance at 1542 nm. By controlling the irradiation conditions, we improved the signal strength coming out from the FBG sensors. A significant reduction in the Bragg wavelength shift was detected in the fabricated FBG sensors for a radiation dose up to 10⁵ gray, indicating excellent radiation resistance capabilities. We also characterized the temperature sensitivity of the radiation-resistant FBG sensors and detected outstanding performance.

We demonstrate the enhancement of antibacterial and cytocompatibility characteristics of femtosecond laser-treated pure titanium and Ti-6Al-4V titanium alloy samples suitable for orthopedic implant applications. We controlled the wettability of the titanium samples by tailoring the surface geometry using a femtosecond laser. To increase the hydrophobicity, laser-assisted micro-grids patterning was performed on the titanium samples, where we achieved a highest contact angle of 144.6° for a 1 µL de-ionized water droplet. In contrast, the hydrophobic Ti-6Al-4V titanium alloy surfaces were converted to hydrophilic surfaces by fabricating periodic micro-gratings on the samples’ surface, where a lowest contact angle of 19.84° was achieved. Furthermore, we assessed the biocompatibility of the micro-patterned titanium samples by investigating the antibacterial activity against Staphylococcus Aureus bacteria. Moreover, the cytocompatibility of the micro-patterned titanium samples was examined using NCTC Clone 929 (L-929) mouse fibroblasts. The laser-treated titanium samples exhibited enhanced antibacterial performance while maintaining excellent cell compatibility. The experimental results confirmed excellent correlation with the wettability of the laser-patterned samples and their antibacterial characteristics and cytocompatibility. Overall, the findings highlight femtosecond laser surface structuring as a highly effective strategy to simultaneously improve antibacterial behavior and the biocompatibility of implant materials, offering a promising way for the advanced functionalization of orthopedic implants.