Development of Self-Sensing Cantilever Structures Using Additive Manufacturing and Optical Fiber Sensing Technology

Fused filament fabrication (FFF) can produce parts that can be integrated with optical fiber sensors to obtain a multifunctional structure. In this study, fibers inscribed with Bragg gratings were incorporated into single cantilever-type accelerometers (fabricated using FFF) from nylon filaments and 17–4 PH to produce structures sensitive to mechanical vibration. The materials were characterized using dynamic mechanical analysis with an optical fiber incorporated into the test specimens, where the nylon specimens presented a transition in elastic modulus until 60 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula>C and for the 17–4 PH the transition occurred until 180 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula>C. Linear regressions were used to estimate the sensitivity of the accelerometers, with calculated coefficients of determination (R<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>) greater than 0.97. The 17–4 PH cantilever had a sensitivity to variation in vibration amplitude (which ranged from 0.5 to 2.0 V) of 1.787 pm/V when vibrated at a frequency of 10 Hz and 3.605 pm/V at 100 Hz, while the nylon accelerometer had sensitivities of 83.114 pm/V and 104.385 pm/V at 10 and 100 Hz, respectively. The manufactured accelerometers have the potential to be used as low-frequency vibration sensors and self-sensing cantilevers in diverse environments.