Wearable, Fabric-Embedded Acoustic Waveguides for Meter-Scale Contact Localization and Force Sensing
Wilfred Mason, JAD ASHKAR, David Brenken, Audrey Sedal
AI summary
Problem
Large-area tactile sensing for wearables and robotics struggles to balance high resolution, manufacturability, and conformability without relying on rigid electronics or complex wiring. Scaling acoustic waveguides to limb-scale, conformable devices remains largely unexplored.
Approach
The team created a wearable sleeve with helically routed acoustic waveguides that convert one-dimensional time-of-flight measurements into two-dimensional contact locations. This design uses sparse, off-the-shelf rangefinders to map touch on curved surfaces while keeping rigid electronics away from the skin.
Key results
- Fabric-embedded sleeve design with helically routed acoustic waveguides
- Accurate 2-D contact localization on flat and curved surfaces via time-of-flight mapping
- Successful touch detection and localization demonstrated on a human arm
- Force estimation via neural networks showed potential but lacked consistent sensitivity
Why it matters
Enables manufacturable, conformable, and mechanically robust tactile sensing for limb-scale wearables and soft robotics, advancing safe human-robot interaction and prosthetic applications.
Abstract
Large-area tactile sensing remains a key challenge for wearable and robotic applications, where solutions must balance resolution and complexity, manufacturability, and con- formability 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 mechan- ical 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.