Quasi-static Tests on a Low Cost Polymer Optical Fiber Curvature Sensor

Abstract

Joint angle measurement is broadly used for understanding human kinematics and different techniques have been proposed throughout several years. Conventional techniques for joint angle assessment are generally costly, bulky and intrusive or have poor portability. Wearable solutions based on inertial measurement unities usually suffer from external perturbations. Considering that polymer optical fiber (POF) is highly flexible, and that is a low cost technology with great immunity from electromagnetic perturbations, a POF based curvature sensor is a promising alternative. This paper presents quasi-static experiments on a curvature sensor. Lateral section on the fiber is made to improve sensor sensibility. Results show a relation between the section dimensions and the hysteresis and signal to noise ratio. Although the hysteresis reduces for proper lateral section dimensions, it is always present due the polymer viscoelasticity. Future studies will aim at modelling and compensating such phenomena for achieving greater precision in angular measurements.