Printed electronics (PE) is an emerging field, with countless possibilities for applications and production techniques. Researchers at the university and corporate level are actively developing new techniques for PE which may open the door for products.
The use of nonwovens is one area that is generating interest. Researchers at North Carolina State University's (NC State) Nonwovens Cooperative Research Center (NCRC), led by Benham Pourdeyhimi, see opportunities for conductive circuits that are either screen printed or digitally printed into nonwoven fabrics.
"There is a significant need for electronically enabled nonwovens and fibrous structures," says Pourdeyhimi, associate dean for industry research & extension, William A. Klopman Distinguished Professor; and NCRC director. "A good example is electronically-enabled packaging materials. Smart nonwovens are finding applications in many technical applications."
Smart nonwovens offer many advantages in applications ranging from textiles to packaging.
"Nonwovens are unique in that they can be engineered to have specific properties and functionalities," Pourdeyhimi notes. "In particular, the surface morphology and properties can be easily manipulated to accommodate, for example, printing a conductive pathway into the structure."
The goal of the NCRC is to be the global leader in nonwovens education and research; the center houses state-of-the-art facilities for product development, analytical services and materials testing, analysis and evaluation. These capabilities are allowing Pourdeyhimi and his colleagues the opportunity to explore a wide range of possibilities.
For example, in one study, "Printing Electric Circuits onto Nonwoven Conformal Fabrics Using Conductive Inks and Intelligent Control," the goal is to continuously print electric circuits onto conformal textile substrates under intelligent control, ultimately producing textile printed circuit boards.
"The work at NC State has highlighted the ways in which the structure can be manipulated to create a surface that can lead to durable, flexible, conformal structures with electronics. Radar antennas, embedded antennas, health monitoring systems, etc., are a few examples of the applications demonstrated," Pourdeyhimi adds.
Conductive textiles can offer a wide range of functionalities, from providing heat or allowing a person to plug in a portable electronic device to providing a means of monitoring health conditions. Nonwovens offer an inexpensive approach for the production of these systems, and NC State's team of professors and students are looking into ways to integrate conductive inks into nonwovens, with an eye toward screen or inkjet printing.
"The structures are flexible, conformal, high strength and durable,"says Dr. Pourdeyhimi. "They can be flexed, laundered, and are inexpensive. The NC State team developed special nonwovens that allow the creation of these structures. The use of screen printing was convenient and inexpensive. However, digital printing of these structures is also possible for more demanding applications. "
Pourdeyhimi notes that the potential markets for conductive nonwovens are varied.
"The technology is more of a platform technology and can be used in a variety of applications," he says. "In particular, we will be targeting health monitoring, tag and track technologies, antennas, electronically enabled packaging, and the like."
In the future, Pourdeyhimi sees opportunities for conductive nonwovens.
"These structures will be used to form interactive, smart sensors and will be important in applications requiring a conductive pathway," concludes Pourdeyhimi.