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This article describes a method to measure the parameters of piezoelectric materials. This is done by evaluating the complex electrical resistance of a sample. However, the properties of the material can not be calculated directly from the electrical resistance. Instead, a simulation model of the sample is created, and the parameters of the simulation model are adapted using an optimisation algorithm until the model's resistance and the resistance of the physical sample match.

In this work, a novel approach to deduce the release of the natural radioactive noble gas ²²²Rn from solid sources containing the isotope ²²⁶Ra is presented. Therein, supporting radioactivity measurements of the source are used in conjunction with a theoretical description of the dynamics. For radiation protection and environmental research, reliable and comparable ²²²Rn measurements, and therefore reference atmospheres of ²²²Rn, are needed. This work improves their realization.

We have managed to reduce the measuring time of previously common hydrogel-based sensors from a few minutes to a few seconds. For this, the arrangement of the hydrogel in the sensor was changed so that the volume of the hydrogel could be reduced. The biggest challenge, apart from generating a very thin pattern, was to firmly bond the hydrogel to a silicon surface. This was to ensure that the resulting forces of the bimorph effect can be absorbed.

In order to save time and avoid overheating of food during unfreezing, the study of ice content can be very useful. The aim of the research is to design an ultrasound-based sensor system that is able to comment on the content of ice in the sample food product. Some sample food products are tested, and the observations and challenges concerning the same are mentioned in the research paper.

Infrared spectroscopy is great for determining the composition of liquids. Combined with attenuated total reflection (ATR), one can just put the sample on the sensitive surface. We made a compact device with a diamond-coated silicon ATR crystal to protect the surface against aggressive fluids. Silicon crystal, light source and detector are hermetically sealed in a housing. Our tests show that the diamond coating enhanced the sensitivity compared to uncoated ATR elements as predicted by theory.

Mathematical models are often required to process sensor data in a digital twin platform. The translation of models to an updateable format enables predicting hidden states of the physical object, which are not directly measurable. The linking of different models is demonstrated by data from field tests on fruit transportation in refrigerated containers. We programmed a streaming platform that enables easy integration of such updatable models with only a few milliseconds of processing overhead.

In this work, we investigated whether artificial feedback in the form of vibration has an effect on the accuracy and precision of eye tracking glasses. The results enabled the development of design proposals for vibrotactile feedback in gaze-based control systems for robotic arms.

In this work, we have developed and validated a semi-automatic approach that greatly reduces the amount of interaction and effort needed for analyzing samples via gas chromatography–mass spectrometry. Further, unlike many other approaches, our developed tool is accessible to the novice and does not require any programming experience. Using whisky as an example substance, we show how the analysis method compares to conventional software, and we validate our approach against that.

The paper describes a novel energy-harvesting system based on the Wiegand effect. The energy provided by this harvester is analysed and correlated to the required energy to start a microcontroller and perform some wireless data transfer. The energy consumption is analysed in detail down to component level. A demonstrator including an additional sensor and wireless transmitter was built, proving that sufficient energy is provided by the harvester for the wireless transfer of the sensor data.

A high-temperature gauge to simultaneously determine electrical conductivity, the Hall constant, and the Seebeck coefficient was developed. Screen-printed heating structures on a ceramic sample holder generate temperatures up to 800 °C. Heating structures were designed using FEM simulations. The temperature distribution was validated by thermal imaging. Measurements on constantan (reference material) and boron-doped silicon wafer confirm the functionality of the gauge up to 800 °C.