A set of screen-printed electrodes. Photo: Washington State University.
A set of screen-printed electrodes. Photo: Washington State University.

The glittering, serpentine structures that power wearable electronics can be created with the same technology used to print rock concert t-shirts, new research shows.

The study, led by researchers at Washington State University (WSU), demonstrates that electrodes can be made using just screen-printing, creating a stretchable, durable circuit pattern that can be transferred to fabric and worn directly on human skin. Such wearable electronics can be used for health monitoring in hospitals or at home.

“We wanted to make flexible, wearable electronics in a way that is much easier, more convenient and lower cost,” said Jong-Hoon Kim, associate professor at WSU Vancouver’s School of Engineering and Computer Science, and corresponding author of a paper on this work in ACS Applied Materials and Interfaces. “That’s why we focused on screen-printing: it's easy to use. It has a simple setup, and it is suitable for mass production.”

Current commercial manufacturing of wearable electronics requires expensive processes involving clean rooms. While some manufacturers use screen-printing for parts of the process, this new method relies wholly on screen-printing, which has advantages for manufacturers, and ultimately consumers.

In the paper, Kim and his colleagues detail the electrode screen-printing process and how they used it to fabricate electrodes that can be used for electrocardiogram (ECG) monitoring. They used a multi-step process for layering polymer and metal inks to create the snake-like structure of the electrode. While the resulting thin pattern appears delicate, the electrodes are not fragile. The study showed they could be stretched by 30% and bend to 180°.

The researchers printed multiple electrodes onto a pre-treated glass slide, allowing them to be easily peeled off and transferred onto fabric or other material. After printing the electrodes, the researchers transferred them onto an adhesive fabric that was then worn directly on the skin by volunteers. These wireless electrodes could accurately record heart and respiratory rates, sending the data to a mobile phone.

While this study focused on ECG monitoring, the screen-printing process can be used to create electrodes for a wide range of uses, which could include performing similar functions to smart watches or fitness trackers, Kim said.

Kim’s lab is currently working on expanding this technology to screen-print different electrodes, as well as entire electronic chips and even potentially whole circuit boards.

This story is adapted from material from Washington State University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.