Special issue  

Hyperspectral imaging (HSI) has the potential to add a beneficial tool for the assessment of transplanted organs. Camera-based technologies such as HSI allow the fast and noninvasive monitoring of relevant physiological parameters. The correlation of HSI-based parameters with functional kidney parameters may be useful for the evaluation of the acceptability of marginal organs, thereby addressing the society-related problem of the shortage of available organs for transplantation.

We have developed a preparation technique to form graphite/TiO₂/Ti and platinum-graphite/TiO₂/Ti solid-state sensors based on plasma electrolytic oxidation (PEO) of titanium foils, whereby a porous titanium oxide layer is formed with well-defined phase composition and a reproducible microstructure. A printing method is used to deposit graphite or catalytically active graphite-platinum electrodes. Our design enables the application of many different detection principles such as calorimetry.

Imaging astronomy spectrographs are designed for recording thousands of spatially resolved spectra of a two-dimensional image field within one single exposure. Transferring this technology to imaging Raman spectroscopy allows a considerably faster acquisition of chemical maps. Within the scope of a research project, this method is refined for medical diagnostics, e.g., the identification of potentially cancerous abnormalities of skin tissue.

Endogeneous electric fields (EFs) affect a wide range of cellular functions such as migration, wound healing and regeneration. Similar results were observed when external EFs are applied. To date, the phenomenon of electrotaxis has been studied only in homogeneous EF environments. Here, we report on the construction and fabrication of a microfluidic biochip as well as first results for stimulation of cells with stationary, non-homogeneous EFs.

A novel cell-cultivation platform with small circulating volume and included oxygen controlling system is presented. This system may be used to investigate the influence of oxygen restriction, called hypoxia, to cultivated human cells and therefore helps to reduce animal testing in this field of research. Furthermore, a mathematic model of the oxygen transport is presented which may be utilized to produce well-defined oxygen microenvironments.

Sensor particles with buoyancy control and position detection are presented, which are used for flow tracking in large vessels, such as biogas digesters and waste water tanks. They were tested in the realistic flows of a biogas digester. The buoyancy control allows taring for good flow tracing by the sensor particles, and it lets them float to the surface after data acquisition for easy recovery. The fluid mixing was estimated from detected passages of sensor particles at a magnetic coil.

Initial steps to apply a new ceramic multi-layer sensor for a Tian–Calvet calorimeter are shown. The FEM-developed sensor consists of stacked ceramic discs and insulation rings. The functionality of the sensor disc was proven up to 600 °C and the entire stack was tested at room temperature. The resolution was 5 µW and the sensitivity was 8.5 µV mW⁻¹. The new sensor shows similar specifications as commercial devices and presents a good starting point for future high temperature applications.

The exploitation of new application fields and the drive to size reduction even in highly stable pressure sensing systems makes the extension of the operating temperature range of the microelectromechanical sensors (MEMS) essential. For this reason, a silicon-based pressure sensor with an application temperature ranging up to 300 °C and the associated manufacturing technology was developed. The evolved sensor has an excellent stability and is uncomplicated to mount due to its stress insensitivity.

The continuous monitoring of industrial and environmental processes is becoming an increasingly important aspect with both economic and societal impact. To realize this task, spectral-optical sensors with their outstanding properties in terms of sensitivity and reliability are a potential solution. However, for exploiting these sensors in a cost- and energy-efficient sensing system, a miniaturized readout unit is needed. Here we present a card-size, inexpensive, and robust readout electronics.