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.