Tattoos and 3D printing feature surprisingly often in wearable health tech. Early wearables typically involved wristbands, headbands, pendants, or smartphone accessories equipped with biosensors, wireless data transmission capability, and software to collect, analyze, and report. Temporary tattoos that could capture and transmit data or alert users soon appeared, providing a “set it and forget it” alternative to wearable devices. Recent examples include LogicInk’s UV sensitive tattoos and TU Graza conductive tattoos for continuous ECG monitoring. As 3D-printed components such as  Duke University’s Wily Lab’s cartilage implants started to appear, federal regulatory groups saw the sea change, and the FDA issued a guidance documentTechnical Considerations for Additive Manufactured Medical Devices. Now both tattoos and 3D printing are conventional elements in health tech development.

Mechanical engineers at the University of Minnesota recently published a research study on technology under development that combines both technology. Their system prints 3D electronics, including sensors, directly on human skin. Combining 3D printing and tattoos on living tissue may be brand new, but the researchers took the work further by designing a portable, lightweight 3D printer that would cost less than $400. Associate Professor and lead author Benjamin Mayhugh said the technology could be a “Swiss Army knife” of the future to print chemical sensors or other electronics as needed directly on the skin. The Minnesota 3D printing technology uses ink made of silver flakes that cure and conduct at room temperature. Computer vision and temporary markers placed on the skin before printing help the printer adjust to the inevitable small movements of the body during printing. The Minnesota technology could be used by soldiers to print temporary sensors to detect chemical agents or solar cells to charge electronics, for two examples. After successfully printing biological cells on a skin wound on a mouse, the engineers also suggested their concept could lead to skin grafts printed directly on patients.

Tattoos and 3D printing in health and medical tech add to the rapidly growing toolbox available to researchers around the world seeking new solutions to problems. It will be interesting to observe as scientists employ other unexpected, and in some case yet-to-be-developed devices or technologies in the search for better medicine and better health.