The impedance measurement is also described as AC resistance measurement. An alternating current is applied to two electrodes and the phase shift between current and voltage is detected. This way, changing effects can be made visible in the vicinity of the impedance sensors, in the area of the developing electrical field. For example, deposits on surfaces can be detected, or changes in material properties in the area of a small penetration depth. In biology, the impedance can be used in Electric Cell Substrate Impedance Sensing to detect changes in morphology of animal cells. For in vitro cell cultures, the electrical impedance at a fixed frequency is given as TEER value. Impedance measurements are also used in the field of electrochemical sensors.
„For impedance measurements with an interdigital transducer (IDT) in a biocompatible environment“