Low cost, easily manufactured, highly flexible strain and touch sensitive fiber for robotics applications

2026-06-11

AI Summary

This work proposes a low-cost, multifunctional sensing fiber for soft robotics, addressing limitations of existing approaches that often rely on expensive materials and complex fabrication processes. The fiber integrates commercially available conductive yarns within silicone tubing and enables dual-modal sensing—resistive strain and capacitive touch/proximity detection—through a simple manual threading process (e.g., 20 cm in under two minutes). Exhibiting high flexibility, ease of fabrication, and reparability, the fiber was successfully integrated into diverse soft robotic systems, including pneumatic grippers for trigger control, flexible bands for pose estimation, soft structures for deformation monitoring, and robotic arms for touch interaction and gesture following. These demonstrations highlight its promising applicability in knitted architectures for wearable and soft robotic applications.

Abstract

Existing stretch and touch sensors for robots are generally expensive with respect to at least one of material costs, required manufacturing equipment, or manufacturing time. We present and experimentally characterize a conductive fiber made using only inexpensive commercial off-the-shelf parts (conductive thread at $0.07/ft, silicone tubing at $0.94/ft) and tools (loop-style needle threader at $2), which can be manufactured quickly (20 cm length in 2 minutes.) We demonstrate its use as a resistive strain sensor with three applications: Triggering a grasp in a pneumatically actuated assistive finger, sensing the pose of a pneumatically actuated robotic strap, and estimating the pose of a flexible solid. We also demonstrate that it can be used as a capacitive sensor with two applications: First, as a touch sensor which triggers a commercial robot arm to move, and second, as a near-field sensor enabling the robot arm to follow a moving hand. The capacitive sensors are knitted, showcasing the high flexibility of the fiber. We discuss methods for improving manufacturing scalability and their cost trade-offs. Finally, we demonstrate a method for repairing a cut fiber.

Problem

• strain sensor
• touch sensor
• flexible fiber
• robotics
• low-cost manufacturing

Innovation

• flexible fiber sensor
• low-cost robotics
• resistive strain sensing
• capacitive touch sensing
• easily manufacturable