A Two-Dimensional Reticular Core Optical Waveguide Sensor for Tactile and Positioning Sensing

Abstract

Tactile sensors based on optical waveguides are highly sensitive to pressure, possess good chemical inertness and electromagnetic resistance, and are unaffected by temperature changes in the surrounding environment. Researchers have developed various waveguide structures with multi-level cores to simultaneously measure tactile forces and positions. However, these designs result in thicker waveguides and reduced sensitivity in the lower levels. This study introduces a two-dimensional reticular core optical waveguide for tactile force and positioning sensing, where vertical waveguides intersect each other. The reticular core reduces waveguide thickness and simplifies fabrication processes. The simulation investigates the characteristics of light propagation and geometric parameters. Experimental results confirm the proposed reticular waveguide's force-sensing capability, with an average sensitivity of 0.36 dB/N. Compared to the split-level structure, the reticular waveguide demonstrates more consistent sensitivities along the two shear directions. Utilizing a deep neural network, the spatial resolution achieves approximately 0.72 mm along the X-axis and 1.14 mm along the Y-axis, outperforming the split-level structure.