Fabric strain sensor integrated with looped polymeric optical fiber with large angled V-shaped notches

This paper presents an investigation of a new fabric strain sensor integrated with a looped polymeric optical fiber (POF) with V-shaped notches of large angle, which is capable of measuring repeated large strain up to 21%. A theoretical model is proposed to describe the sensing behavior based on reflection from the incident sides of the V-notch on a bent fiber. The relationship between the normalized output power of the sensor and the fabric strain is derived. Verification experiments demonstrate a good agreement obtained with the numerically simulated results. Further discussions on the effects of geometric parameters of the sensors shed new light on the optimization of the sensor performance.