Project A4 - ΔE-Effect Sensors

The ΔE-effect magnetic field sensor is particularly suited for measuring low-frequency AC fields. It avoids 1/f noise by utilizing the frequency shift of a high frequency electromechanical resonator from the change in the Young’s modulus of a magnetostrictive component in a magnetic field. The sensor allows broadband magnetic field measurements down to the DC range and is resistant to microphony and mechanical noise. In particular, our sensor concept developed in Kiel provides full device integrability that will now be explored in the second funding period. As a final goal, we plan to develop fully integrated ΔE-effect sensors and sensor arrays including sensor electronics in a single unit. Initially, for cost savings and flexibility in design and testing, the development of the mechanical part, based on MEMS technology, and the electronics will occur on separate chips. The design of the magnetoelectric MEMS resonators will be based on the developed anisotropic magnetoelastic and electromechanical ΔE-effect models and will include the relevant losses, in particular clamping, eddy currents, and thermomechanical losses. The realization of the micromechanical design as a MEMS device is intended via Europractice, which provides prototyping and low volume production of MEMS structures separately as well as complementary metal oxide semiconductor (CMOS) technologies for integrating the sensor electronics. Especially, we plan to use the PiezoMUMPS technology of Europractice, as it already offers integration of the required piezoelectric AlN layer. The magnetic layer will be deposited as a final step in Kiel. Here, exchange biased films are also envisioned. In addition to providing robust, fully integrated magnetic field sensors with a broad bandwidth and huge dynamic range, we also plan to explore the possibility of using sensor arrays with a large number of integrated sensors for increased resolution, noise reduction, and improved limit of detection. While, in principle, each sensor could be operated with its own electronics, total power consumption and challenges in parallel channel processing will require the development of proper grouping strategies as well as readout and excitation schemes. The already well-established larger sensors will serve as a benchmark for the miniaturized sensor elements and will also be further investigated in parallel.


Involved Researchers

Person Role
Prof. Dr. Franz Faupel
Materials Science
Multicomponent Materials
Project lead
Prof. Dr. Robert Rieger
Electrical Engineering
Networked Electronic Systems
Project lead
M.Sc. Fatih Ilgaz
Materials Science
Multicomponent Materials
Doctoral researcher
M.Sc. Patrick Wiegand
Electrical Engineering
Networked Electronic Systems
Doctoral researcher
Dr.-Ing. Benjamin Spetzler
Micro- and Nanolelectronic Systems
Technische Universtität Ilmenau
Associated member


Role within the Collaborative Research Centre

Cooperate with the following projects:

A1 (Magnetostrictive Multilayers for Magnetoelectric Sensors) Magnetic characterization and layer deposition.
A5 (Piezotronic Magnetoelectric Composites) Sensor electronics.
A6 (Microstructure and Structural Change of Magnetoelectric and Piezotronic Sensors) Structural analysis of magnetic component.
A10 (Magnetic Noise of Magnetoelectric Sensors) Magnetic noise modelling and analysis.
B1 (Sensor Noise Performance and Analogue System Design) Noise measurements and reduction.
B2 (Digital Signal Processing) Dual-mode operation and signal processing.
B7 (3D-Imaging of Magnetically Labelled Cells) Application of ∆E sensors and arrays for cell localizations.
Z1 (MEMS Magnetoelectric Sensor Fabrication) Design and manufacturing of established single ∆E sensors for applications in the CRC.


Project-related Publications

F. Ilgaz, E. Spetzler, P. Wiegand, F. Faupel, R. Rieger, J. McCord, B. Spetzler: Miniaturized Double-Wing ∆E-Effect Magnetic Field Sensors, Scientific Reports, vol. 14, no. 11075, 2024. 
E. Spetzler, B. Spetzler, J. McCord: A Magnetoelastic Twist on Magnetic Noise: The Connection with Intrinsic Nonlinearities, Advanced Functional Materials, no. 2309867, 2023. 
S. Simmich, P. Wiegand, R. Rieger: Noise Efficient Three-Channel Amplifier for MEMS Cantilever Readout, 19th Asia Pacific Conference on Circuits and Systems, conference proc., 2023. 
S. Simmich, R. Rieger: Analysis of Current-Reuse and Split-Voltage Topology for Biomedical Amplifier Arrays, IEEE PRIME, Villasimius, Italy, 2022. 
B. Spetzler, P. Wiegand, P. Durdaut, M. Höft, A. Bahr, R. Rieger, F. Faupel: Modeling and Parallel Operation of Exchange-Biased Delta-E Effect Magnetometers for Sensor Arrays, MDPI Sensors, vol. 21, no. 22, 759, 2021.
S. Simmich, A. Bahr, R. Rieger: Noise Efficient Integrated Amplifier Designs for Biomedical Applications, MDPI Electronics, Special Issue: Analog Microelectronic Circuit Design and Applications, vol. 10, issue 13, 2021.
B. Spetzler, C. Bald, P. Durdaut, J. Reermann, C. Kirchhof, A. Teplyuk, D. Meyners, E. Quandt, M. Höft, G. Schmidt, F. Faupel: Exchange Biased Delta-E Effect Enables the Detection of Low Frequency pT Magnetic Fields with Simultaneous Localization, Scientific Reports 11, Article no. 5269, 2021.
B. Spetzler, E. V. Golubeva, R.-M. Friedrich, S. Zabel, C. Kirchhof, D. Meyners, J. McCord, F. Faupel: Magnetoelastic Coupling and Delta-E Effect in Magnetoelectric Torsion Mode Resonators, Sensors, vol. 21, no. 6, 2021.
P. Durdaut, E. Rubiola, J.-M. Friedt, C. Müller, B. Spetzler, C. Kirchhof, D. Meyners, E. Quandt, F. Faupel, J. McCord, R. Knöchel, M. Höft: Fundamental Noise Limits and Sensitivity of Piezoelectrically Driven Magnetoelastic Cantilevers, Journal of Microelectromechanical Systems, vol. 29, issue 5, 2020.
B. Spetzler, C. Kirchhof, J. Reermann, P. Durdaut, M. Höft, G. Schmidt, E. Quandt, F. Faupel: Influence of the Quality Factor on the Signal to Noise Ratio of Magnetoelectric Sensors Based on the Delta-E Effect, Applied Physics Letters, vol. 114, issue 18, 183504, 2019.
J. Schmalz, B. Spetzler, F. Faupel, M. Gerken: Love Wave Magnetic Field Sensor Modeling — from 1D to 3D Model, International Conference on Electromagnetics in Advanced Applications (ICEAA), pp. 0765-0769, 2019.
A. Kittmann, P. Durdaut, S. Zabel, J. Reermann, J. Schmalz, B. Spetzler, D. Meyners, N. X. Sun, J. McCord, M. Gerken, G. Schmidt, M. Höft, R. Knöchel, F. Faupel, E. Quandt: Wide Band Low Noise Love Wave Magnetic Field Sensor System, Scientific Reports, vol. 8, no. 278, 2018.
P. Durdaut, J. Reermann, S. Zabel, C. Kirchhof, E. Quandt, F. Faupel, G. Schmidt, R. Knöchel, M. Höft: Modeling and Analysis of Noise Sources for Thin-Film Magnetoelectric Sensors Based on the Delta-E Effect, IEEE Transactions on Instrumentation and Measurement, vol. 66, no. 10, pp. 2771-2779, 2017.
S. Zabel, J. Reermann, S. Fichtner, C. Kirchhof, E. Quandt, B. Wagner, G. Schmidt, F. Faupel: Multimode Delta-E Effect Magnetic Field Sensors with Adapted Electrodes, Applied Physics Letters, 108, 222401, 2016.