Depending on the type of skin sticker used, applying pressure to the sticker could, for example, answer an incoming call or adjust the volume of a music player.
The stickers act as an input space that receives and executes commands and thus controls mobile devices.
"The stickers allow us to enlarge the input space accessible to the user as they can be attached practically anywhere on the body," said Martin Weigel, a PhD fellow at Saarland University.
The 'iSkin' approach enables the human body to become more closely connected to technology.
Users can also design their iSkin patches on a computer beforehand to suit their individual tastes.
"A simple graphics programme is all you need," said Weigel.
One sticker, for instance, is based on musical notation, another is circular in shape like a Long Play (LP) record.
The silicone used to fabricate the sensor patches makes them flexible and stretchable.
"The music player can simply be rolled up and put in a pocket," said lead researcher Jurgen Steimle.
"They are also skin-friendly, as they are attached to the skin with a bio-compatible, medical-grade adhesive. Users can therefore decide where they want to position the sensor patch and how long they want to wear it," Steimle added.