Simple ballpoint pen can write custom LEDs

Researchers working with Chuan Wang, an associate professor of electrical and systems engineering at the McKelvey School of Engineering at Washington University in St. Louis, have developed ink pens that allow individuals to handwrite flexible, stretchable optoelectronic devices on everyday materials including paper, textiles, rubber, plastics and 3D objects.

In a paper published Aug. 7 in Nature Photonics, the team reports their simple and versatile fabrication approach to allow anyone to make a custom light-emitting diode (LED) or photodetector without the need for any specialized training or bulky equipment. The new handheld fabrication technology builds on earlier work by Wang and first author Junyi Zhao, a doctoral candidate in Wang’s lab, in which they demonstrated a novel way to fabricate stretchable LEDs with an inkjet printer.

“Handwriting custom devices was a clear next step after the printer,” Wang said. “We had the inks already, so it was a natural transition to take the technology we had already developed and modify it to work in regular ballpoint pens where it could be cheap and accessible to all.”

Read more on the McKelvey School of Engineering website.