Researchers from the University of Minnesota have used a low-cost 3D printer to print wearable electronics onto a hand for the first time. This is huge for many industries. Directly printed electronics can be used by soldiers during battle to detect chemical or biological agents around them, or in solar cells to charge electronics, like your cell phone.
Along with printed electronics, the same 3D printer has printed biological cells on a wound on a mouse’s skin. This opens up a whole new world for the medical community and could lead to groundbreaking developments for skin grafts and more. The team, along with Jakub Tolar from the University of Minnesota Department of Pediatrics, was able to successfully use a bio-ink to print cells.
"We are excited about the potential of this new 3D-printing technology using a portable, lightweight printer costing less than $400," said Michael McAlpine, the study's lead author and the University of Minnesota Benjamin Mayhugh Associate Professor of Mechanical Engineering. "We imagine that a soldier could pull this printer out of a backpack and print a chemical sensor or other electronics they need, directly on the skin. It would be like a 'Swiss Army knife' of the future with everything they need all in one portable 3D printing tool."
The new 3D printing technology allows the printer to adjust to any small movements the person might make during the printing process. As shown in the video, before the printing process is started, temporary markers are placed on the person’s skin and then the machine scans the skin. The printer uses computer vision to adjust to any movements that the person makes during the printing process.
"No matter how hard anyone would try to stay still when using the printer on the skin, a person moves slightly and every hand is different," McAlpine said. "This printer can track the hand using the markers and adjust in real-time to the movements and contours of the hand, so printing of the electronics keeps its circuit shape."
The new technique uses specialized ink made of silver flakes that can cure and conduct at room temperature. Other 3D printing inks need to cure at high temperatures, making them impossible to use on human skin because it would burn the skin. Once the person is done using the electronics, they can just peel it off with tweezers or wash it with water.
The paper on this new 3D printing process was published in the journal Advanced Materials.