Particularly with a car, reliable functioning of the sensors is necessary, especially in the presence of snow and ice. Heating elements are attached directly to or integrated into the sensor. The heating elements can be printed onto flexible substrates, for example onto polycarbonate, PET or PI films. The final temperature determines which film is used. As a rule, for the applications described the printed heaters are not visible and the heat is, for example, emitted indirectly. Classical silver, copper or carbon pastes are well suited for these applications. However, there are also transparent heating elements which can be printed onto glass, for example in order to heat mirrors, windscreens and rear windows. In all cases, contact to a current source is required. Furthermore, the current load and capacity of the voltage source must be matched to the design, the size and the required temperature. This requires the continuous control and stability of the screen-printing machine printer  in order to ensure the correct coating thickness of the printed conductive ink. A change in the coating thickness would result in overheating or a malfunction. Other than with graphical printing, for printed electronics it is necessary to ensure a stable, uniform coating thickness and conductivity, whereas the coloring is less important.  

Many companies already specialize in the conception and design of such heating elements. The printability of such functional screen-printing pastes has been developed optimally and user-friendly. This enables long screen times together with fast drying.  

Besides silver- and carbon-based pastes with fixed resistance, pastes with adjustable resistance play an important role in the area of printed heating. These pastes allow the precise adjustment of the required resistance for the heating structure.