More Skin, More Control

A group of researchers from Saarland University in Saarbrücken, Germany, is giving a new meaning to the phrase “comfortable in your own skin.” In a remarkable application of human-computer interaction technology, the research team, led by Martin Weigel, is working on research concepts for uber-thin temporary electronic tattoos that turn your skin into touch-sensitive buttons.

The research is on temporary electronic tattoos called SkinMarks, developed under Saarland University’s Human-Computer Interaction research project. Both were developed by Weigel’s team, which included Jürgen Steimle and colleagues from Google.

“We make use of the elastic properties of the skin, including bending and stretching,” Steimle said in an interview with New Scientist.

The technology prints wires and electrodes on temporary tattoo paper using a conductive ink. The tattoos come out thinner than the width of human hair. Capable of lasting a couple of days before completely rubbing off, the e-tattoo can be transferred onto skin using water.

Skin and Screen Improvement

According to Weigel, SkinMarks can be put on bumps and birthmarks — or other notable skin features, such as wrinkles and freckles — which people intuitively know. As such, these are ideal for touch-sensitive buttons. For example, it’s possible to adjust the volume of your smartphone by sliding your finger across a tattoo placed on the side of another finger. Bending this tattooed finger, however, turns the volume slider into a play and pause button.

An added feature that makes SkinMarks stand out from other e-tattoos is electroluminescent. The tattoos glow whenever a current passes through it. A tattoo shaped like your favorite app can light up when you receive a notification.

“Now we’ve tested the technological feasibility, the next step is to look at implementing it in a practical way,” Weigel said to New Scientist.

Chris Harrison from Carnegie Mellon University thinks the technology will be available in 10 years. “You’ll have these digital tattoo parlours which you can go to in 2050 and 5 minutes later you can walk out with the iPhone 22 on your forearm,” he said in an interview with New Scientist.

“This is amazing research,” he added, noting that the skin gives a bigger surface area than any smartphone out there. “Human fingers are quite nimble on their own skin.”