Research on novel, flexible sensor systems based on two-dimensional material systems

Since January 1st, 2021, the institute of General Electrical Engineering and Plasma Technology (AEPT) has been a member of the ForMikro project FlexTMDSense, which is funded by the BMBF, for "researching new types of flexible sensor systems based on two-dimensional material systems". Within the scope of this project, ultra-thin pH and gas sensor systems based on two-dimensional (2D) semiconductor films of the material class of transition metal dichalcogenides are investigated. However, this transparent, flexible and biocompatible 2D sensor system is not yet fully developed for industrial mass application.

The AEPT will support the FlexTMDSense project with its plasma diagnostic expertise and contribute to the development of new types of sensor and electronic systems based on 2D materials. The focus here is on the plasma diagnostic investigation of novel monolayer-precise etching technologies, which represents an important intermediate step within the entire process chain in the manufacturing of flexible sensors. The ideal is to achieve complete control, optimization and predictability of the entire etching process. This is intended to produce high-quality and cost-effective sensors with tailored properties in a reproducible manner at a high throughput rate. The complex interactions within a plasma-assisted etching process and its interaction with the layer to be removed are still incompletely understood. Consequently, an important goal of the AEPT is to use the knowledge-based approach using the existing plasma diagnostics in combination with the surface analysis of the project partners to gain a sound physical and chemical understanding of the entire process. The research focus is on the possible control of process-relevant plasma parameters through the application of customized voltage signals to the antenna and the substrate electrode of the RIE module (RIE: reactive ion etching). With this Voltage Waveform Tailoring (VWT), in contrast to the classic excitation with sinusoidal voltage signals, both particle fluxes and their energy distribution can be tailored. With the knowledge obtained, low-damage, selective and monolayer-precise etching processes for the mass production of 2D sensor technology become a reality.

For the application there would be the possibility to transfer the know-how developed in the sub-project to the manufacturers. In addition, the knowledge-based approach to process development that is common in research could be established through knowledge transfer in industry.