Body blemishes, freckles, wrinkles and birthmarks can now be turned into touch-sensitive buttons with the help of ultrathin temporary electronic tattoos that allow you to control your smartphone.

According to Martin Weigel, a research lead at Saarland University in Germany, people have an intimate and intuitive knowledge of the features of their own skin such as bumps and birthmarks, making them ideal areas for touch-sensitive buttons. This means, you could slide a finger over your knuckles to change the volume of your speakers or tap a freckle to answer a phone call.

E-tattoos can turn your freckles and skin features into smartphone controls

The study at Saarland University saw Weigel and his colleagues use conductive ink to print wires and electrodes on temporary tattoo paper, which they call SkinMarks - thinner than the width of human hair, like those temporary tattoos you get when you're a kid/attending a music festival.

The touch-sensitive tattoos are also electroluminescent which means they glow when a current passes through it - so they could light up when you receive a notification.

Don't get too excited, the research team say it may be up to 10 years before we see these SkinMarks in mainstream use. Bring on 2027!

E-tattoos can turn your freckles and skin features into smartphone controls