ABSTRACT
It is difficult to give a proper categorization of the sensing effects due to the large variety of material structures and physical/chemical interaction phenomena that can be used to fabricate sensors based on sensing polymer films. Considering the electric sensing devices that are based on the change of their electrical parameter, it is well known that there are insulating and (semi)conductive polymers, but the possible conduction mechanisms within the latter type are less known. Electronically conducting and semiconducting polymers have attracted a great deal of interest as sensing layers applied in sensors. There are two types: composites that contain an electrically insulating polymer matrix loaded with a conductive filler and polymers that are intrinsically conducting or can be made so by doping. The sensing effects in polymers can be described using the following grouping of materials: dielectrics, conductive composites, electrolytes, sorbents, membranes with receptor molecules, permselective membranes, ion-exchange membranes, optically sensitive polymers, and electroconducting conjugated polymers.
