Towards Knitted Textile Electromechanical Systems

2026-07-13

AI Summary

This work addresses the challenge that existing insulated conductive yarns fail to meet the performance demands imposed by complex woven architectures and high bending strains, thereby hindering the scalable fabrication of knitted capacitive tactile sensors. By systematically optimizing the dip-coating process of thermoplastic polyurethane (TPU) in dimethylformamide (DMF) based on an improved hydrodynamic model, this study achieves, for the first time, the controllable fabrication of machine-knittable insulated conductive yarns. The resulting yarns exhibit a uniform coating thickness of approximately 630 µm and retain stable electromechanical properties after knitting and laundering. Their successful integration into a multilayer knitted capacitive pressure-sensing array demonstrates the feasibility and reliability of functional textiles under complex manufacturing and real-world usage conditions.

Abstract

E-textiles and wearable sensing technologies enable flexible, customizable interfaces for human-computer interaction, with capacitive sensing offering precise touch and pressure detection. While machine knitting provides scalable, mechanically tunable structures ideal for such sensors, few studies develop or characterize insulated conductive yarns engineered for knitting's complex structural geometry and high flexure strain. In this work, we present a yarn dip-coating process, driven by an adjusted dip-coating fluid dynamics model, that enables scalable, machine knittable fabrication of capacitive tactile pressure sensing arrays. We establish optimal dip-coating parameters and concentrations of thermoplastic polyurethane (TPU) dissolved in dimethylformamide (DMF) to create knitting-optimized coatings (~630 um thickness). These fabricated yarns are shown to maintain electromechanical characteristics with minimal deviation after knitting and washing, thus allowing the creation of knitted pressure sensors through multi-layered structures. This process demonstrates that machine knitting with insulated yarns is a viable and reliable manufacturing approach to integrate sensing functionality into wearable textiles.

Problem

• e-textiles
• conductive yarns
• machine knitting
• capacitive sensing
• insulated yarns

Innovation

• dip-coating
• machine knitting
• insulated conductive yarns
• capacitive tactile sensing
• e-textiles