An international team of researchers has developed cotton-based e-textiles that combine carbon nanotube and reactive silver inks through inkjet printing. This technique maintains fabric comfort while enabling conductivity, washability, and heat resistance. The resulting devices include tactile sensors and heaters that withstand ironing, washing, and bending, demonstrating a major step toward wearable applications built directly into everyday garments without losing cotton’s natural breathability and flexibility.
- The process used poly-L-lysine coating to enhance adhesion between cotton fibres and printed nanomaterials, ensuring stability during washing and repeated usage cycles.
- Carbon nanotubes acted as conductive networks while also enabling silver ion reduction, resulting in precipitation of dense nanoparticles after controlled thermal treatment.
- Electrical conductivity achieved 1.25 × 10⁵ S m⁻¹, significantly surpassing carbon nanotube-only electrodes and creating reliable conductive paths on the woven cotton surface.
- The study, ‘Washable heat-resistant and inkjet-printed devices on cotton fabric for wearable applications’, was published in Nature Communications. The authors are Kyubin Bae, Bowoong Heo, Kyuhyun Hwang, Eunhwan Jo, Yunsung Kang, Soonjae Pyo and Jongbaeg Kim from University of Texas at Austin, Yonsei University, Kumoh National Institute of Technology, Kyungpook National University and Seoul National University of Science and Technology.
INSIDE THE RESEARCH: The study aimed to overcome the long-standing difficulty of achieving conductivity on cellulose-based fibres. Printing carbon nanotubes first screened out hydroxyl groups that normally inhibit silver ion reduction. Sequential application of reactive silver ink then produced silver nanoparticles that filled voids between nanotubes, yielding robust conductive patterns while maintaining cotton’s inherent softness, breathability, and flexibility compared with synthetic substrates used previously.
- Sequential printing on poly-L-lysine-treated cotton improved adhesion and prevented detachment of nanomaterials after washing cycles, extending long-term device stability.
- Heating the silver-ion-coated nanotube layers at 100 °C for 30 minutes resulted in uniform precipitation of silver nanoparticles across the cotton fibres.
- Conductivity was enhanced dramatically compared with printing only carbon nanotube ink or silver ink separately, proving the advantage of the combined sequential method.
- The experimental process demonstrated reproducibility across multiple samples, indicating scalability for fabricating e-textiles in consistent batches for wearable applications.
WHY IT MATTERS: Cotton remains the most widely used clothing fibre globally, yet integrating electronics into natural fabrics pose challenges. Prior approaches often sacrificed comfort, breathability, or durability. The current project shows that cotton’s appeal can be preserved while embedding advanced electronic functions. Such developments expand opportunities for wearable healthcare, sports apparel, and consumer clothing markets, potentially transforming everyday garments into responsive, functional devices with lasting performance.
- The method enables integration of conductive elements directly into cotton without relying on synthetic coatings that often reduce comfort or breathability.
- Demonstrated wash resistance indicates that future smart garments could withstand consumer laundering processes without degradation of performance or appearance.
- Retained heat resistance allows garments to survive ironing near 200 °C, crucial for practical household care and long-term usability.
- The development offers alternatives to polymer-based wearables, which can irritate skin or fail after prolonged use, improving user acceptance of electronic textiles.
FROM LAB TO LIFE: The cotton-based e-textiles progressed beyond laboratory characterisation into practical demonstrations. Tactile socks distinguished walking from running by analysing current changes, while heating gloves maintained warmth during hand movements. These use cases highlight how the technology could integrate seamlessly into apparel, supporting healthcare monitoring, fitness applications, and thermal comfort solutions. The results suggest readiness for scaling from prototypes to consumer-level clothing innovations.
- Socks embedded with tactile sensors tracked gait differences by producing distinct signal peaks during walking compared with running.
- Gloves containing heaters provided consistent thermal sensation even when the user clenched and unclenched their hand repeatedly.
- Everyday clothing integration demonstrates practicality far beyond rigid laboratory testing conditions, bridging research and consumer adoption.
- Combining comfort, washability, and performance places cotton e-textiles at the forefront of next-generation wearable device development.
