Professor Dr. Mathias Kläui

Johannes Gutenberg-Universität Mainz
Fachbereich Physik, Mathematik und Informatik
Institut für Physik

Dr. Denys Makarov

Helmholtz-Zentrum Dresden-Rossendorf (HZDR)
Institut für Ionenstrahlphysik und Materialforschung
Subject Area Electronic Semiconductors, Components, Circuits, Systems
Synthesis and Properties of Functional Materials
Experimental Condensed Matter Physics

Project Summary

When combined with wireless communication systems, soft, flexible and transient smart sensorics for instance for monitoring physiological conditions is at the forefront of multidisciplinary research bridging materials science, physics, electrical engineering, and medicine. While in particular spintronic devices have been developed for communication and sensing applications, they have largely not been explored on flexible and stretchable surfaces. Wireless magnetosensorics can pave the way towards on-skin proximity detection systems for touchless human-machine interaction, motion and displacement sensorics, as well as functional medical implants. Magnetoresistive elements are envisioned to act as a versatile tool to assess for instance the mechanical movements of heart valves in vivo to diagnose early stages of dysfunctions.We will explore spintronic devices for combined high frequency bendable sensor and communications systems. We will fabricate a demonstrator consisting of a flexible magnetoresistive element integrated into a flexible resonant circuit with an antenna and capacitor and demonstrate transmission of the measured sensor signal to an external device, i.e. a smartphone. To realize the communication with the entirely passive flexible device, which could serve e.g. to sense the heart function, we will fabricate monitoring electronics. To ensure the necessary transparency in the human body as needed for the implant applications, the device will be designed to work in the tens of MHz frequency range.To realize this vision, we use a multi-pronged approach that combines the necessary fundamental investigations with applied development, which can only be achieved by combining the know-how of two groups. Firstly, we have to understand the behavior of flexible magnetic sensors from DC-GHz frequencies exposed to tensile or compressive strain occurring due to the flexibility. In particular, we need to ascertain the intrinsic magnetic properties as well as the resulting transport properties, as reflected in the fundamental aspects of the project. On the application side, we will realize the flexible resonant circuit and monitoring electronics, where we aim to tune the resonance frequency and the Q-factor of the circuit using the external magnetic field that will be sensed.