Researchers at North Carolina State University printed multiple layers of electrically conductive ink on polyester fabric to make electronic textiles that they want to use in the development of wearable devices.
The authors have learned to print electronic textiles at room temperature and under normal atmospheric conditions, which they say is an effective method of making such a material. The authors plan to use the textile printing technique not only in the flexible electronics industry but also in the textile industry.
Inkjet printing is a rapidly evolving new technology used in flexible electronics to print film on mobile phone displays and other devices. We believe this printing method is also promising for the creation of electronic textiles in wearable devices.
In their work, the authors used the FUJIFILM Dimatix inkjet printer: with it, they made a durable and flexible material to create. One of the main issues during production was finding the right composition of materials: it was necessary that liquid ink did not seep through the porous surface of textile materials and did not lose its ability to conduct electricity.
As a result, the authors layers of electrically conductive silver ink like a sandwich around two layers of liquid materials: they acted as insulators. A polyester fabric was placed on top of the sandwich layers. After they printed layers of silver ink and insulating materials, the authors began observing the behavior of the material with a microscope.
Researchers have found that the chemical properties of insulating materials as well as textile threads are important: they provide electrical conductivity for the liquid silver ink, and also prevent them from penetrating the porous fabric.
During the tests, electronic textiles were bent 100 times: they did not lose their electrical characteristics. In future work, the authors plan to improve the electrical characteristics of the materials, as well as increase the breathability of the material.
After all, they want to use a printing method to create electronic textiles that can be applied to wearable electronics, such as heart rate tracking.