Investigation of Vibration and Mechanical Stress in Neural Thin-Film Interfaces during Electrical Stimulation (NeuroVibes)

• Applicant: Professor Dr.-Ing. Thomas Stieglitz
• Subject Area: Biomedical Systems Technology
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 461626908

The long-term stability of implantable and flexible thin-film electrodes is a crucial prerequisite for successful applications in neuroscience research, clinical diagnosis and rehabilitation. Although metal electrodes have been used as neuronal interfaces with great success, delamination and cracking can be observed in especially thin metal layers during prolonged electrical stimulation. A systematic investigation of the failure mechanisms is the aim of the proposal "NeuroVibes", whereby especially the electro-mechanical coupling in thin-film materials is assumed to be the main cause. The deformation oscillations of platinum thin-film electrodes due to electrical excitation will be measured for the first time with high spatio-temporal resolution with a digital holographic microscope. In addition, investigations of chemical mass transport near the electrode during electrochemical charge transfer will be carried out and novel integrated pH sensors will be developed to detect corrosive exchange reactions and chemical imbalances. The experimental studies are verified with computer models simulating the mechanical deformation behavior of membranes, e.g. under mechanical cyclic loading. The obtained model is used as a guide for the stimulation parameters and the development of more stable electrode geometries.Thus, the crucial demand for longevity in neuroprosthetics can be addressed, but the results can also contribute significantly to the stability of all electrolytic electrode configurations, e.g. fuel cells in motor vehicles, capacitors or batteries.

• DFG Programme: Research Grants
• Major Instrumentation: Digital Holographic Microscope
• Instrumentation Group: 4190 Spezielle Geräte der Mikrosystemtechnik