3D printer creates sensors on hand to detect chemicals, charge devices

April 25 (UPI) — Researchers have developed a new use for low-cost 3D printers: sensors on a hand to detect chemical or biological agents, as well as a way to charge electronic devices with solar cells.

Besides being used to print wearable devices, 3D printing technology has potentially life-saving applications. Among other uses, soldiers on the battlefield could print temporary sensors on their bodies and doctors could print cells to help those with skin diseases, researchers say.

The research by the University of Minnesota was published Wednesday in the journal Advanced Materials.

“I’m fascinated by the idea of printing electronics or cells directly on the skin,” Dr. Michael McAlpine, an associate professor of mechanical engineering at Minnesota, said in a press release. “It is such a simple idea and has unlimited potential for important applications in the future.”

To print on a person’s hand, the skin is scanned and temporary markers are placed on the skin. Then, three layers of the sensor are printed.

The sensors can be removed either by peeling them off with tweezers, or they can just be washed off with water.

With the new technique, researchers said, the printer also can adjust to small movements of the body during printing — which are inevitable.

“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.”

In normal 3D printing, ink needs to cure at high temperatures up to 212 degrees Fahrenheit. That wouldn’t work, because it would burn a person’s hand, so scientists instead use a specialized ink made of silver flakes that cure and conduct at room temperature.

“We are excited about the potential of this new 3D printing technology using a portable, lightweight printer costing less than $400,” McAlpine said. “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.

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