Chemistry laboratory

The chemistry laboratory at the Institute of Biomedical Engineering and Informatics enables chemical, preparative, analytical and other experimental work to be carried out. The laboratory equipment includes eight wet-chemical workbenches and a fume cupboard as well as the basic equipment and facilities of a chemistry laboratory. In addition, the laboratory is equipped with all relevant safety measures so that work with hazardous substances or potentially dangerous chemical reactions (toxic/corrosive substances) is possible. A chemical store is attached to the chemistry laboratory. In addition to the basic equipment, the laboratory is equipped with special devices. The laboratory is used for classical training in the Bachelor's and Master's degree courses. The laboratory is used for practical experiments on "Dialysis" and "Clinical laboratory and analytical measurement technology". The equipment in the chemistry laboratory is also used to work on research projects. A particular focus here is the production and characterization of magnetic nano- and microparticles, fabrication of polymer-based dry electrodes, and hydrogels.

• Production of magnetic nano- and microparticles

Magnetic nano- and microparticles are interesting materials for various medical applications in diagnostics and therapy as well as imaging techniques. Corresponding particles in the size range from 10 nm to 10 µm are produced in chemical laboratories using wet chemical processes. For medical applications, these particles must be converted into biocompatible ferrofluids by applying a coating layer. Furthermore, the particles are sterilized by UV irradiation for use in biological systems and their sterility is tested using microbiological test procedures. The picture shows typical magnetic nano- and microparticles. The particles produced are then tested in the NanoTheranostics laboratory, for example, for their suitability for use in controlled drug release, in magnetically targeted administration in the body, in magnetic hyperthermia as a minimally invasive tumor therapy and as a contrast agent for magnetic particle imaging.

• Production and coating of dry Ag/AgCl electrodes

Silver/silver chloride dry electrodes (Ag/AgCl) are becoming increasingly important and enable new applications in the field of medicine and mobile EEG recording. The electrode substrate, a polymer, is initially produced in a rapid prototyping process (rapid prototyping laboratory). This makes it possible to quickly and efficiently adapt the geometry or Shore hardness, for example. The electrode substrate is initially not yet electrically conductive, so a chemical coating is necessary. The substrate is thoroughly cleaned at the start of the process. In several individual coating steps, a robust silver layer a few micrometers thick is deposited on the substrate. After sufficient drying, the silver-plated electrodes are chlorinated in the final step. After this process, the originally non-conductive electrode substrate is electrically conductive and the Ag/AgCl electrode is ready for EEG applications. The following examples demonstrate the difference between the uncoated and coated substrate.