The sensors can be used in multifunction steering wheels to control music, light, and ventilation in cars. (©Photo Fraunhofer ISC)
Researchers have created flexible silicone sensors that make it easier to steplessly control devices such as a multifunction steering wheel that lets the driver control music, light, and ventilation at the touch of a finger. Multifunction steering wheels are standard in most automobiles today, and drivers can easily manipulate the cruise control and stereo without taking their hands of the wheel. However, the buttons are inflexible and the driver can often only switch something “on” and “off.”

The new sensors have been designed like an electrical capacitor – two electrode layers consisting of a conductive silicone above and below, and one insulating film layer in between. In order for the pressure to have an effect, the researchers applied additional layers of silicone on the film. Thus, for example, two more films press from above and below to put additional pressure on the film in the middle. The sensor‘s electrical capacitance is different in each case. The researchers can use these differences and adapt the design of the sensors individually to different geometries and sensitivities.