Temporary tattoos are all the rage these days. What if you could connect those tattoos to your electronic devices? Thanks to a team of scientists from Carnegie Mellon University and the University of Coimbra, Portugal, you might be able to do just that.
The researchers have developed a method to make robust and flexible tattoo-like circuits. The team added trace amounts of an electrically conductive liquid metal alloy to conventional temporary tattoo paper. And like today’s temporary tattoos, the circuits can be applied to human skin with water or a damp sponge—and washed away just as easily.
The tattoo is created by printing circuits made of silver nanoparticles with a regular inkjet printer. The circuits are then coated with gallium indium, a liquid metal alloy. The tattoo is sintered at room temperature, which causes the alloy to bind with the silver to create a circuit. Using an inkjet printer and avoiding costly high-temperature sintering results in a low-cost process.
“We would use an electronic tattoo to create circuits that could go on the body to power any type of devices…on your skin,” said Majidi. This means they could possibly charge—and communicate with—a smart watch, a heart monitor or a health and activity tracker. They could also be used for soft robotics and flexible displays.
In fact, they are flexible enough to conform and stick to highly curved 3D surfaces, like a model of a human brain or a lemon. This opens up the possibility of using them for under-the-skin health monitoring.
The findings have been published in Advanced Materials.
Unlike conventional tattoos, these electronic versions could not only look cool—they could also serve an important function. And unlike regular tattoos, you can get rid of them easily should you come to regret the decision to get one!
Read more about wearable technologies at LogicInk Tattoos Act as Wearable UV Sensors.