The potential of portable electronic devices goes far beyond smart watches or speakers, home sensors and devices in our vehicles. Despite this, the need for batteries and integrated circuits is inevitable and smart clothing, such as connected jackets or pants with sensors, is not as comfortable to wear with these gadgets. At least until now. A solution, developed by scientists led by Yingying Zhang, has been printing flexible fibers in textiles. For example, they printed patterns on fabrics, which can collect and store electricity. With a 3D printer equipped with a coaxial needle (a guide needle with several axes), they drew patterns, images and letters on a piece of cloth and thanks to it they were able to transform the movement into energy. The results have been published in Matter.
“We use a 3D printer equipped with a homemade coaxial nozzle to directly print fibers in textiles and we show that it could be used to produce and manage energy,” Zhang explains. “We use a coaxial nozzle because the single-axis nozzles allow printing only one ink. at the same time, which greatly restricts the diversity of the composition and design of printed forms.”
Zhang’s team turned to two types of inks: a solution of carbon nanotubes to build the conductive core of the fibers and silk for the insulating sheath (although other laboratories could choose materials that adjust flexibility, biocompatibility, and impermeability that search). The injection syringes filled with the inks were connected to the coaxial nozzle, which in turn was connected to a conventional 3D printer.
This approach differs from that of other groups that manually sew electrical components, such as LED fibers, into fabrics, a process that requires multiple steps and time. The advantage of using a 3D printer is that you can build versatile features on fabrics in one step. The approach is also cheap and easy to take to large-scale production.
“Our long-term objective,” concludes Zhang, “is to design flexible and portable hybrid materials and, at the same time, develop new techniques for the practical production of intelligent portable systems with integrated functions, such as detection, activation and communication among others.”