Multi-point force sensor based on crossed optical fibers

The objective of this paper is to present a sensor concept based on optical fibers suitable crossed in order to obtain a multi-point force sensor. The working principle exploits the optical power losses due to the fiber bending. The bending losses highly depend on the curvature of the fiber. Firstly, an analytical model that relate bending losses to fiber curvature is introduced and experimentally validated. After the demonstration of the proposed concept potentiality, a design procedure based on the simultaneous use of the analytical model and a Finite Element (FE) model is described. The procedure is experimentally validated for a single crossing of fibers and it is used to realize a complete sensor prototype. Finally, the sensor prototype is experimentally calibrated as a multi-point force sensor.