Wearable textile-based electronics show great promise for applications such as human/computer interfaces or medical sensing and monitoring. Printing of conductive inks on prefabricated fabrics is a low-cost and scalable route to wearable electronics, but the formulation of suitable inks is challenging.

Takao Someya, University of Tokyo, Japan and colleagues have developed an ink that allows for both patterning during the printing process and shows very good permeation into the textile structure. The researchers achieved this through the combination of different components in their ink, each serving a particular purpose: A fluoroelastomer provides softness and stretchability, the low vapor pressure solvent butyl carbitol acetate enables deep penetration into the fibers, and low-cost silver flakes serve as the conductive filler.

Textiles treated with this ink showed an initial sheet resistance of 0.06 Ω sq^–1 which increased 70 times after stretching the material by 450 %. To demonstrate their approach for medical monitoring applications, the team successfully designed a multichannel electromyogram monitoring garment.

• Enhancing the Performance of Stretchable Conductors for E-Textiles by Controlled Ink Permeation,
  Hanbit Jin, Naoji Matsuhisa, Sungwon Lee, Mohammad Abbas, Tomoyuki Yokota, Takao Someya,
  Adv. Materi. 2017.
  DOI: 10.1002/adma.201605848