A label called Multi-Touch Skin has been developed that can be attached to any part of the body and control electronic devices wirelessly.

In 2015, Germany's Saarland University introduced the labels of the iSkin. These labels were able to control mobile devices when affixed to the body. Now, Prof. The team, led by Jürgen Steimle, developed a new technology based on this technology, known as the Multi-Touch Skin.

Can detect multiple touches

The Multi-Touch Skin, which prints on a thin PET plastic in an inkjet printer in less than a minute and can then be glued to any part of the body, can take any two-dimensional shape. The labels, which are placed on top of each other and are prepared with two layers of electrodes made up of rows and columns, work in conjunction with a touch control microchip. The microchip is also connected to a Raspberry Pi Zero micro-computer that runs on a small battery.

This chip continuously measures the electrical resistance at the intersections of the electrode braid. When the user touches a certain point of the item, the fingertip transmits electricity and causes the electric current to decrease. The chip determines the resistance change there and interprets this change as touching this point. Multi-touch is possible because the changes at different points can be perceived in the same way.

These interacting signals can be wirelessly transmitted to another electronic device. These devices can react differently depending on the detected touch traces.

Different application areas

Researchers have used this technology in four different touch control interfaces to date. These include a bracelet where a user can rotate two fingers to change the color of an LED lamp and adjust the light intensity by moving his or her fingers back and forth; a label affixed to the back of the ear that allows the voice of a music player to be turned on and off by touching it back and forth and switching between songs by touching the left and right; a sticker attached to the front handle that allows a smartphone to send a message when it's tightened, and a sticker that is placed in the palm of your hand and allows the user to answer calls from your smartphone.

The study was presented at the Human Factors in CHI Computing Systems Conference in Montreal.