At first glance, Fraunhofer IPA 's proximity sensor does not look particularly spectacular: a thin, elastic silicone layer with black square areas printed on it. What looks like paint, however, are countless microscopically small carbon nanotubes that can locate people or objects. "The proximity sensor recognizes everything that is electrically conductive. As soon as an object approaches, the electric field changes," explains IPA scientist Florian Bodny. However, this can only be seen when it is connected to evaluation electronics: As soon as a hand or a metallic object is held over it, the lamp lights up. This not only detects the object, but also its position if the surface consists of several sensor elements.

The IPA scientists have used a combination of silicone and CNT for the sensor. The structure is built up in layers: A layer of silicone is followed by a layer of silicone-CNT mixture. Both materials are elastic, flexible and have high environmental stability. This means that the sensor can also be applied to large surfaces. Screen printing is used as the manufacturing process, as the method is fast and does not require complex preparations. It is also possible to print large areas and produce the sensors in large quantities.

Various applications are possible for the proximity sensor: for example, it could be used as an artificial skin for robots. "Service robots, for example, can extend their hand when they recognize a person," explains Bodny. There are also many possible applications in the 'smart home' sector, such as for lamps or doors that open or close as soon as a person stands in front of them. Thanks to its elasticity, the sensor is also suitable for accident prevention, for example on workwear and protective clothing. The scientists are also considering using it in medical technology for exoskeletons. Bodny explains: "The sensor is available immediately. We are still looking for partners from industry and research who want to test and further develop it."