Elastic conductive inks for reliable smart textiles

Traditionally, textile-integrated electronics use wrapped or tension-relieved conductive yarns. While effective, these methods are complex and costly, making them impractical for large-scale production. 

• Loss of conductivity under stretching or strain 

• Cracking or tearing of prints during movement 

• Degradation through repeated washing 

• Weak bonding between textile and printed layer 

• Fragile connections between conductive and electronic elements 

To overcome these challenges, the DITF’s Color- and Functional-Printing Working Group is focusing on new ink and paste formulations that combine conductive particles with elastic binders. The elastic properties of the binder are largely determined by the auxiliaries and additives used. 

The team studies the interactions between components to achieve formulations that maintain electrical performance during mechanical deformation. These inks are designed to stretch and move with the textile substrate without losing functionality. 

Central to the research is the concept of hysteresis, the material's ability to retain its properties under repeated strain. 

A well-balanced hysteresis ensures that: 

• The electrical conductivity remains stable over time 

• The material can adapt to movement without losing function 

• Long-term use under real-life conditions is feasible 

This allows for the creation of smart textiles suitable for medical devices, wearable sensors, or therapeutic clothing used by physiotherapists, nurses, and physicians. 

By enhancing the understanding of interactions between conductive particles, binders, additives, and textile auxiliaries, the DITF team aims to enable cost-efficient, scalable production of printed electronic textiles. The project could significantly reduce production costs and support the widespread use of wearable electronics in healthcare, rehabilitation, and beyond. 

COMPAMED-tradefair.com; Source: Deutsche Institute für Textil- und Faserforschung Denkendorf