Enhancing the Performance of Stretchable Conductors for E‐Textiles by Controlled Ink Permeation

• Published in: Advanced materials (Weinheim) Vol. 29; no. 21
• Main Authors: Jin, Hanbit, Matsuhisa, Naoji, Lee, Sungwon, Abbas, Mohammad, Yokota, Tomoyuki, Someya, Takao
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.06.2017
• Subjects: biometric devices; Boiling points; composite materials; Conductors; Deformation; Electrical resistivity; e‐textile; Formability; Human body; Inks; Materials science; Permeation; printed electronics; Printing; Robust control; Smart materials; Strain; stretchable conductors; Stretching; Textiles; Vapor pressure; Wearable technology; Wiring; printed electronics; biometric devices; stretchable conductors; composite materials; e-textile
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201605848

Delivery of electronic functionality to the human body using e‐textiles is important for realizing the future of wearable electronics. Printing is a promising process for large scale manufacturing of e‐textile since it enables arbitrary patterns using a simple and inexpensive process. However, conductive inks printed atop of textile are vulnerable to cracking because of the deformable and porous structure of textiles. The authors develop a mechanically and electrically robust wiring by controlling ink permeation in the structure of textile. This is done by adjusting the ink's solvent. The use of butyl carbitol acetate, with its low vapor pressure and boiling point, enables deep permeation into the textile. The sheet resistance is initially 0.06 Ω sq−1, and the resistance increasing only 70 times after stretching to 450% strain. Finally, a four‐channel electromyogram (EMG) monitoring garment is demonstrated to show the potential of a large‐scale e‐textile device for health care and sports. A textile‐permeable conductive ink for stretchable e‐textiles is developed. The permeation process enables the utilization of the textile's wavy structure, allowing for the fabrication of highly stretchable printed e‐textiles. The sheet resistance is 0.06 Ω sq−1, and the resistance increases only 70× after stretching to 450% strain. Finally, four‐channel EMG monitoring of a skin‐tight garment is demonstrated by this textile‐permeable conductive ink.