Researchers from the University of Minnesota have developed a method to print electronics on a human hand for the first time using a customized 3D printer.
The new technology could enable soldiers to print temporary sensors to detect chemical or biological agents or solar cells to charge essential electronics, as well as print medical treatments to heal wounds and directly prints grafts for skin disorders.
According to the study, conventional 3D printing technologies typically rely on open‐loop, calibrate‐then‐print operation procedures.
The new 3D closed loop printing technique can adjust to small movements of the body during printing. The researchers already demonstrated the ability to print biological cells on a skin wound on a mouse.
“We are excited about the potential of this new 3D-printing technology using a portable, lightweight printer costing less than $400,” Michael McAlpine, the study’s lead author and the University of Minnesota Benjamin Mayhugh Associate Professor of Mechanical Engineering, said in a statement. “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 technique works when temporary markers are placed on the skin, which are then scanned while the printer uses computer vision to adjust to movements in real-time.
“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.”
A specialized ink made from silver flakes is also used to cure at room temperature, while other inks require high temperatures to cure that would ultimately burn the human skin.
The person can peel off the electronic device with tweezers or wash it off with water to remove the electronics from their skin.
Along with the military applications, the new technology can enable doctors to print cells to help those with skin diseases.
“I’m fascinated by the idea of printing electronics or cells directly on the skin,” McAlpine said. “It is such a simple idea and has unlimited potential for important applications in the future.”
The study was published in Advanced Materials.