ABSTRACT

There are two basic elements of sensor operation. The first is the physical or chemical interaction between the environment and the sensing material that alters the material properties (“sensing effect”), while the second is the “transduction mechanism” inside the sensor structure that converts this material property change into a useful signal, which then holds information about the environment-material interaction. In this chapter, various sensor device structures and their transduction mechanisms are described independent of the possible real sensing effect, which is the subject of Chapter 4. The most important sensor device structures can be categorized into the following groups:

• Impedance-type sensors follow the sensing phenomena with capacitance, resistance, and/or inductance changes.