By Kathleen Berger, Executive Producer for Science and Technology

Imagine high-tech ink used in a ballpoint pen for writing custom LEDs! It’s being developed inside a Washington University in St. Louis laboratory.

“When people think about light emitting diodes (LEDs), they don’t think of that as something everyone can make. The cell phone screen, the computer screens, they’re all light emitting diodes,” said Chuan Wang, PhD, associate professor of electrical and systems engineering at the McKelvey School of Engineering at Washington University in St. Louis. “Five or 10 years down the road, people will be able to go to any store and buy a pen similar to normal pens that they use, and they will be able to write light emitting devices on all types of objects that they use in daily life. And the pattern that they wrote on those objects would then become a display, to display the information they want.”

That’s Wang’s vision for LED displays, to become something anyone can make for themselves using a ballpoint pen. The personalized light emitting displays could be used in many ways, starting with handwritten notes. A user could find any surface of choice to draw, then fill, for the creation of a display of any size and shape used for apps or watching videos. The flexible and stretchable optoelectronic devices are good for use on paper, textiles, rubber, plastics and 3D objects.

So, just how is this possible? First author Junyi Zhao, a doctoral candidate in Wang’s lab, formulated the material into a solution, which becomes the ink. The material is layered, stretchable and flexible. In the HEC Media video, Zhao demonstrates using a simple ballpoint pen to write custom LEDs.

Wang and Zhao said the new technology can be used in applications for education.

“Science popularization helps to pique the interest, especially in the young kids,” said Wang.

There would be every day uses, including biomedical applications.

“For health care applications, we’re not selling the pen, actually. We’re selling this idea,” said Zhao.

“The field has a growing demand or interest in developing personalized wearable devices to track health,” said Wang.

Wang said the technology can be used to create a smart bandage that can also be used to help heal wounds.

“Illuminating the wound with an infrared light can actually speed up the healing process,” he said.

And there could be an application for smart shipping and receiving, including everyday package deliveries.

“Write a label on top and that label actually works as a display for smart packaging,” explained Wang. “And after that, the ink can be washed off and can be reused for the next round of shipping applications.”