Wearable, Fabric-Embedded Acoustic Waveguides for Meter-Scale Contact Localization and Force Sensing

Abstract

Large-area tactile sensing remains a key challenge for wearable and robotic applications, where solutions must balance resolution and complexity, manufacturability, and conformability to various geometries. While acoustic waveguides have been used for contact localization and force estimation at the centimeter scale, scaling this technology to limb-scale wearable devices is unexplored. In this work, we introduce a soft, wearable tactile sleeve based on wrapped and meter-length acoustic waveguides. By patterning waveguides on a sleeve, one-dimensional time-of-flight measurements are mapped to two-dimensional contact locations. This enables conformable coverage with sparse transducers, while preserving mechanical robustness by placing rigid electronics away from the contact surface. We contribute the design and fabrication of the waveguide-based tactile sensor, provide an in-depth characterization of sensor response and evaluate frameworks for contact localization and force estimation, and demonstrate system performance on a human arm. Results show that the time-of-flight-based localization approach generalizes across contact sizes and curved geometries. However, more work is required to achieve sensitive and reliable force estimates. This work establishes acoustic waveguides as a manufacturable and reconfigurable modality for wearable tactile skins.