► Megahertz Organic Thin-Film Transistors for Flexible Biomedical Systems

Dr. Hagen Klauk

Max-Planck-Institut für Festkörperforschung (MPI-FKF)

Professor Dr.-Ing. Alexander Klös

Technische Hochschule Mittelhessen
Campus Gießen
Fachbereich 02 – Elektro- und Informationstechnik

Professor Dr.-Ing. Yiannos Manoli

Albert-Ludwigs-Universität Freiburg
Institut für Mikrosystemtechnik (IMTEK)


Project Summary

The goals of this project are the optimization of organic thin-film transistors (TFTs) and the advancement of organic-TFT-based analog and mixed-signal circuit design to enable the realization of low-power biomedical systems on flexible polymeric substrates. A special focus is on neural interfaces, such as cochlea implants. For this purpose, the factors that currently limit the cutoff frequencies of flexible low-voltage organic TFTs with channel lengths of 1 µm to about 1 MHz for p-channel TFTs and 100 kHz for n-channel TFTs will be investigated by numerical simulations. The results of these simulations will be used to optimize all critical aspects of the TFT fabrication process, such as channel length, gate overlap, semiconductor thickness and contact doping, with the goal of increasing the cutoff frequencies of both p-channel and n-channel organic TFTs fabricated on plastic substrates beyond 1 MHz. By taking advantage of high-resolution stencil masks for the device fabrication, TFTs with channel lengths well below 1 µm can be manufactured. The design of analog and mixed-signal circuits, including frequency mixers, analog filters, voltage stabilization circuits, electrical references and neural stimulators, will be supported by the development of optimized DC and AC device models. The entire wireless system will be integrated on a flexible polymeric substrate.