Biomedical sensors long ago moved out of the hospital and into an assortment of recreational exercise devices monitoring heart rate, blood pressure, respiration and other vital signs.
Whether medical or recreational activity trackers, these sensors require some sort of carrier — think wristbands or EKG electrode patches — which limits their effectiveness and can make them uncomfortable when worn for extended periods. They can also be hard to place and often have poor signal quality.
Now, right out of science fiction, engineers at Penn State, China’s Harbin Institute of Technology and other Chinese institutions have come up with a way to print the sensors and their electronics directly on human skin.
Up to now, the only way to bond nanoparticles together to create flexible electronics was through a process requiring temperatures hotter than the hottest home oven. The new process uses common materials that allow the particles to bond at room temperature.
The resulting sensor is flexible, smooth and durable enough to remain on the skin until peeled off with hot water. The devices can then be recycled and reused.
Lead researcher, Penn State Engineering Professor Huanyu Cheng, explained that the bonding process uses polyvinyl alcohol paste — the main ingredient in peelable face masks — and calcium carbonate — the key ingredient of eggshells.
The sensors, he said, “Are capable of precisely and continuously capturing temperature, humidity, blood oxygen levels and heart performance signals.”