MUNICH, Germany - Nanotechnology not only puts an entirely new dimension before the eye, it also makes audible things that no ear could ever perceive before, like changes in temperature. A new varnish developed by researchers at the Fraunhofer Institute for Engineering and Automation IPA ensures that surfaces emit sound if they become warmer or cool off. The trick: carbon nano-tubes that are embedded in the varnish and that conduct electricity. If a surface is coated with this varnish, it can be heated up by application of an electric current. This change in temperature is audible because the warming-up surface makes the air around it vibrate.
 
“This is only one of a myriad of conceivable innovative applications. The surface coating is likewise capable of heating large surfaces and surfaces of complex shape, and in the future, conceivably it can be used as a multifunctional coating for heating, or as a resistance sensor, or as a coating for color displays,” said Ivica Kolaric, Department Head at IPA.