Abstract: The invention concerns a layered structure comprising at least two material layers. The layered structure is formed of a conductive polymer on a substrate material layer to allow a reaction in the conductive polymer material when the layered structure is exposed to the surrounding conditions. The invention also concerns a method for producing layered structure. In the method the conductive polymer material is applied on the substrate material by printing or spraying or stamping or casting or spin coating or by using photolithographic or laser ablation method or a combination of these. The invention further concerns a sensor comprising an electric device short circuited by the conductive polymer of the layered structure. In the sensor a change in the conductive polymer initiates a change in the function of the electric device.

Abstract: A heated roll and a method for heating of a roll, in particular of a press roll or calender roll in a paper or board machine. The roll has a hollow, tubular roll mantle. The roll is heated with electric current by means of electrical resistors fitted inside the body material of roll mantle. The heating is preferably applied to the roll substantially at the proximity of the face of the roll mantle, and the electric current may be supplied to the electrical resistors from the ends of the roll through glide rings.