High bending curvature withstanding one dimensional angle sensor with fiber Bragg gratings

We report on the development of an angle sensor which can measure at high bending curvature. Unlike the other sensors, the novel angle sensor can be durable and flexible. The sensors consist of one fiber Bragg grating (FBG) fiber which is located in the middle of each sensor, and are fabricated in varying thickness to confirm the relation between the distance of the center of the angle sensor to the core of the FBG node and the radii of curvature at which the sensor can measure. The thinnest sensor has the thickness of 200 μm and can measure at the bending radius of 5 mm. However, its angle measurement error is the largest with 1.25°, because of high sensitivity. Regulating the thickness of sensor, the angles at high curvatures can be measured reliably.