Fiber Bragg grating load cell using 3D printing technique

Load cells are the core of any weighing system. Currently, the load cells using electrical strain gauges are most commonly used. However, conventional load cells present some drawbacks due to the susceptibility to electromagnetic interferences and incapability of harsh environment applications. We developed a fiber Bragg grating (FBG) load cell embedded in a polymer 3D printed material that overcomes these limitations due to intrinsic properties of the optical fibers. This paper describes the design of the FBG load cell using the finite element method (FEM), as well as experimental studies of the load and temperature characteristics. The sensing structure consists of a triangular-shape 3D printed base and a cantilever on which the FBG was attached. When subjected to load, the FBG sensor presented an approximate sensitivity of 1.59 ± 0.09 pm/g, and resolution of 0.66 g of applied load. The temperature characterization was also performed to assess the 3D printed polymer influence and a nonlinear behavior was attained.