Researchers Use Inkjet Technology to Print Conductive Material on Textiles

Researchers at North Carolina State University have found a way to print layers of electrically conductive ink onto polyester fabric at room temperature, creating a new method of manufacturing wearable tech that uses inkjet printing technology.

“Inkjet printing is a rapidly advancing new technology that’s used in flexible electronics to make films used in cellphone displays and other devices,” said Jesse S. Jur, professor of textile engineering, chemistry and science at N.C. State and the study’s corresponding author. “We think this printing method, which uses materials and processes that are common in both the electronics and textiles industry, also shows promise for making e-textiles for wearable devices.”

The researchers used a FUJIFILM Dimatix printer to create the e-textile material. The challenge was finding a perfect balance of materials so the liquid didn’t seep through the fabric used in the research and lose electric conductivity.

In a new study, @NCState textile researchers demonstrated they could print layers of electrically conductive ink on fabric to make an e-textile that could be used in the design of future #Wearables: https://t.co/vIlvgvkbKX

— NC State News (@NCStateNews) June 22, 2021

The solution was to print layers of conductive silver ink “like a sandwich” around layers of liquid materials, which all were then printed on woven polyester. Using those layers of silver ink as a sandwich around the other materials allowed the silver to act as insulators and maintained the conductivity.

“We wanted a robust insulation layer in the middle, but we wanted to keep it as thin as possible to have the entire structure thin, and have the electric performance as high as possible,” Inhwan Kim, the study’s first author, said, adding that creating a structure layer-by-layer hadn’t been done on a textile fabric with inkjet printing before. “Also, if they are too bulky, people will not wear them.”

In the end, the researchers were able to create a flexible and, most importantly, comfortable item that could be implemented in biomedical devices or athletic performance wear.

While this is in the early stages and more proof-of-concept than anything, the ubiquity of inkjet printing opens up the possibility for wider adoption of technology like this in the future.