An Evaluation of Multi-Component Weft-Knitted Twill Structures for Sensing Tensile Force

TL;DR

This paper evaluates multi-component weft-knitted twill structures as resistive sensors for tensile force measurement, demonstrating their fabrication, integration, and performance characteristics, including stability, hysteresis, and drift.

Contribution

It introduces a novel approach using twill-knit structures with conductive yarns for tensile force sensing, highlighting fabrication methods and performance improvements.

Findings

Tighter knitting of resistive yarn enhances sensor consistency.

Adding Lycra improves elastic recoil and sensor performance.

Loop composition significantly affects measurement reliability.

Abstract

We present multi-component knitted resistive sensors for tracking tensile force. The knits were fabricated using a Twill structure, which is a simple pattern featuring anisotropic elastic behavior, providing high stability along course-direction. Our sensors are made of two commercially available conductive yarn types, with highly different linear resistance. We present a variety of integration methods using the proposed Twill structure, all of which can be easily replicated on a two-bed weft-knitting machine. We evaluate the performance of the resulting sensor variations, with respect to consistency, hysteresis, short-term and long-term relaxation and drift, among other metrics. We found that particulars of the knit's loop composition have a crucial effect on the consistency of the sensor readings. Furthermore, we show that knitting resistive yarn more tightly than the substrate material gives superior results and that improving elastic recoil by adding Lycra to the supporting substrate can considerably improve performance.