Even though we usually do not even notice them, sensors are ubiquitous in our modern society. Sensor applications span a variety of different areas, such as health care, automotive and smart homes. However, not only is the applicability of sensors in different fields enormous, but the operating principles of sensors are also diverse: capacitive and resistive sensors, piezoelectric transducers, magnetic sensors, etc. Depending on the application, the data obtained from the sensors is helpful in many ways, such as in optimization and maintenance.
In our working group, different types of sensor systems are being investigated:
In potentiometric oxygen sensors of the "lambda probe" type, for example, a Ni/NiO buffer system can be used as an internal reference. For this type of sensor, the correct understanding of the kinetics of the Ni/Ni2+ redox reaction plays an important role, as these determine the stability and accuracy of the sensor. Thus, we employ high-temperature voltammetry to investigate the reaction mechanisms and reaction rates of this redox system.
Other sensors that we study go in a rather different direction. We use them to examine biological substances by measuring the change in the electrical properties of the sensor (e.g. Hexaaminruthenium (II)/(III) redox probes). This is achieved by monitoring the electrode impedance, which is influenced by interactions between the substance(s) of interest with the activated sensor surface.
In brief, our work aims to increase the fundamental understanding of existing sensor systems and to provide a proof of principle for novel sensor variants.