In a paper out in the journal Advanced Materials, researchers present a ground-breaking new technique of using a customised, low-cost 3D printer to print electronics directly on the back of the hand for the first time.
The printed devices are not harmful to the skin and can be easily peeled off with tweezers or simply washed away with tap water.
Once the technology matures, similar techniques could be used to print chemical or biological sensors, or even mini-solar cells, on the bodies of soldiers to charge essential electronics and detect signs of biological warfare in the battlefield where access to electronics is often limited.
What’s more, the research team also succeeded in printing live cells on the skin wound of a mouse, thereby paving the way for advanced regenerative medicine applications, such as direct printing of grafts for skin disorders and other injured tissues.
“We are excited about the potential of this new 3D-printing technology using a portable, lightweight printer costing less than $400,“ said lead author on the study Associate Professor of Mechanical Engineering at the University of Minnesota Michael McAlpine.
“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.”
To avoid any significant distortions which could result due to involuntary movement, the target surface is equipped with temporary markers which guide the printer through computer vision in real-time.
Unlike with most 3D-printers, the new technique relies on a specialised ink containing silver flakes, which allows it to cure and conduct at room temperature. In contrast, other 3D-printing inks currently on the market require temperatures of up to 100 degrees Celsius, making them unsuitable for printing on live tissue.
“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”.