Nature Communications (Sep 2024)

A fabrication strategy for millimeter-scale, self-sensing soft-rigid hybrid robots

  • Hun Chan Lee,
  • Nash Elder,
  • Matthew Leal,
  • Sarah Stantial,
  • Elenis Vergara Martinez,
  • Sneha Jos,
  • Hyunje Cho,
  • Sheila Russo

DOI
https://doi.org/10.1038/s41467-024-51137-8
Journal volume & issue
Vol. 15, no. 1
pp. 1 – 16

Abstract

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Abstract Soft robots typically involve manual assembly of core hardware components like actuators, sensors, and controllers. This increases fabrication time and reduces consistency, especially in small-scale soft robots. We present a scalable monolithic fabrication method for millimeter-scale soft-rigid hybrid robots, simplifying the integration of core hardware components. Actuation is provided by soft-foldable polytetrafluoroethylene film-based actuators powered by ionic fluid injection. The desired motion is encoded by integrating a mechanical controller, comprised of rigid-flexible materials. The robot’s motion can be self-sensed using an ionic resistive sensor by detecting electrical resistance changes across its body. Our approach is demonstrated by fabricating three distinct soft-rigid hybrid robotic modules, each with unique degrees of freedom: translational, bending, and roto-translational motions. These modules connect to form a soft-rigid hybrid continuum robot with real-time shape-sensing capabilities. We showcase the robot’s capabilities by performing object pick-and-place, needle steering and tissue puncturing, and optical fiber steering tasks.