To make comfortable, wearable electronics, a group of researchers in China has developed a 3D printer that deposits electronic flexible fibers onto transitional textiles or clothes. According to an article in Innovation In Textiles, researchers at Tsinghua University in Beijing printed patterns that can harvest and store electricity onto fabrics. With a 3D printer equipped with a coaxial needle, they drew patterns, pictures and lettering onto fabric, giving it the ability to transform movement into energy.
“We used a 3D printer equipped with a homemade coaxial nozzle to directly print fibers on textiles and demonstrated that it could be used for energy-management purposes,” said senior author Yingying Zhang, a professor in the Dept. of Chemistry. “We proposed a coaxial nozzle approach because single-axial nozzles allow only one ink to be printed at a time, thus greatly restricting the compositional diversity and the function designing of printed architectures.”
Zhang and her colleagues made their first 3D printed e-textiles using two inks: a carbon nanontube solution to build the conductive core of the fibers, and silkworm silk for the insulating sheath. Injection syringes filled with the inks were connected to the coaxial nozzle, which was fixed on the 3D printer. These were used to draw customer-designed patterns.
This approach differs from other groups who are manually sewing electrical components, such as LED fibers, into fabrics, but these multi-step processes are labor intensive and time consuming. The strength of using a 3D printer is that it can build versatile features into fabrics in a single step. The approach is also cheap and easy to scale, as the nozzle is compatible with existing 3D printers, and the parts can be swapped. However, the resolution of what can be printed is limited to the mechanical movement accuracy of the 3D printer and size of the nozzles.
“Our long-term goal is to design flexible, wearable hybrid materials and electronics with unprecedented properties and, at the same time, develop new techniques for the practical production of smart wearable systems with integrated functions, such as sensing, actuating and communicating, said Zhang.”
The researchers described their 3D printing efforts in a paper published in Matter, a new materials science journal from Cell Press.