Etched singlemode polymer fiber Bragg gratings for high sensitivity tensile force measurements

Singlemode polymer fiber Bragg gratings (FBG) are etched up to a thickness of 30 μm to be used for high sensitivity tensile force measurements. The singlemode polymer fiber and the gratings are fabricated using the in-house fabrication facility. The fabricated cladding etched polymer FBGs are characterized for low value tensile force measurements and the sensitivity of the sensors are measured and compared with the theoretically estimated values. A sensitivity of 643 nm/N is obtained for the polymer Bragg grating with a diameter of 30 μm. Given the bio-compatible nature of polymer fibers, such high sensitivity force sensors can found applications in bio-medical field where high sensitivity low value force/pressure measurements are required.