Three-core fiber Bragg grating probe force estimation model for micromanipulation applications

This paper proposed a three-core fiber Bragg grating (FBG) probe for sub-millinewton contact force measurement of a micromanipulator system. The probe comprises a bundle of three single-core FBGs assembled under the effect of capillary self-assembly. Theoretical relationships between Bragg wavelength and force are calculated based on the assumption of material mechanics. The experimental results show that the probe has a good linear relationship for the measurement of the radial two degrees of freedom contact force, and it is suitable for measuring the radial contact force of 0.1–1 mN. The proposed three-core FBG probe has the characteristics of simple structure, low cost, and better forming stability and sensitivity compared with the four-core structure.