Development of an Elastic, Electrically Conductive Coating for TPU Filaments.

Henriette Grellmann,Mathis Bruns,Felix Michael Lohse,Chokri Cherif,Iris Kruppke,Andreas Nocke

doi:10.3390/ma14237158

Abstract

Electrically conductive filaments are used in a wide variety of applications, for example, in smart textiles and soft robotics. Filaments that conduct electricity are required for the transmission of energy and information, but up until now, most electrically conductive fibers, filaments and wires offer low mechanical elongation. Therefore, they are not well suited for the implementation into elastomeric composites and textiles that are worn close to the human body and have to follow a wide range of movements. In order to overcome this issue, the presented study aims at the development of electrically conductive and elastic filaments based on a coating process suited for multifilament yarns made of thermoplastic polyurethane (TPU). The coating solution contains TPU, carbon nanotubes (CNT) and N-Methyl-2-pyrrolidone (NMP) with varied concentrations of solids and electrically conductive particles. After applying the coating to TPU multifilament yarns, the mechanical and electrical properties are analyzed. A special focus is given to the electromechanical behavior of the coated yarns under mechanical strain loading. It is determined that the electrical conductivity is maintained even at elongations of up to 100%.

Highlights

Since DuPont first introduced elastic polyurethane (PU) fibers under the brand nameLycra in 1962, a wide range of applications for yarns with high structural elongation has been developed [1]
In order to overcome this drawback and to introduce a novel method of producing electrically conductive and elastic fibers, this study presents a possibility to surround highly elastic yarns made of thermoplastic polyurethane (TPU) with an electrically conductive coating
This opens up new fields of application in the area of smart textiles and soft robotics, where the electrically coated elastic yarns can be used as sensors and actuators

Summary

Introduction

Since DuPont first introduced elastic polyurethane (PU) fibers under the brand name. Lycra in 1962, a wide range of applications for yarns with high structural elongation has been developed [1]. In order to overcome this drawback and to introduce a novel method of producing electrically conductive and elastic fibers, this study presents a possibility to surround highly elastic yarns made of thermoplastic polyurethane (TPU) with an electrically conductive coating In this way, TPU, a classic textile fiber product that is already used in many applications, can be equipped with additional functionality through a subsequent processing step. TPU, a classic textile fiber product that is already used in many applications, can be equipped with additional functionality through a subsequent processing step This opens up new fields of application in the area of smart textiles and soft robotics, where the electrically coated elastic yarns can be used as sensors and actuators

Used Materials

Development of the Coating Solution and Coating Process

Test Methods

Findings

Conclusions