Project Z1 - MEMS Magnetoelectric Sensor Fabrication

The primary objective of this project is the microelectromechanical systems (MEMS) fabrication of magnetoelectric (ME) sensors to enable the realization of the CRC's scientific work program and to provide the different projects with fully or partially processed sensors for their research tasks. While new sensor concepts are pioneered in the A projects, the B projects need a sufficiently large number of reliable sensors with reproducible sensor characteristics. Thus, Z1 acts as the interface between the project areas A and B. It provides technological support to the A projects and makes the new findings of these projects available for the B projects.

To achieve this objective, Z1 maintains a technology platform providing both full fabrication flows as well as separate process modules. Z1 closely collaborates with the A projects during the technological realization of new sensor concepts, which results in separate process modules to aid the research. Upon maturity of the sensor concepts, the separate process modules are integrated to a full fabrication flow, capable of providing fully fabricated sensors for the projects of area B. In this way, the project regularly implements new sensor concepts and technologies into the technology platform, making them accessible to all projects in the CRC.

Within the first funding period, a cross-institutional technology platform has been established. This platform combines the capabilities of CAU and ISIT in the field of bulk-micromachining (BMM) and surface micromachining (SMM), and in the processing of different materials. At present, the platform comprises three full process flows for various designs of resonant, ΔE-effect sensors and sensors for frequency conversion approaches. In addition, process modules are provided for fabrication of electrically modulated, piezotronic, and surface acoustic wave (SAW) sensors.

This existing technology platform will serve as a starting point for the proposed funding period. In the course of the studies, the platform will be revised, extended, and adapted to the newest findings in and needs of the research projects. The work plan focuses on technology platform revisions, fabrication of MEMS ME sensors as well as integration of new concepts and materials. The next steps for the technology platform include – but are not limited to – the integration of the separate process modules into a full flow for the fabrication of SAW sensors and the integration of a process module for powder-based permanent magnets (projects A1, A2).

 

Involved Researchers

Person Role
Dr. Dirk Meyners
Materials Science
Inorganic Functional Materials
Project lead
Dr.-Ing. Florian Niekiel
Materials Science
Micro-Manufacturing Processes
Project lead
Dr.-Ing. Anne Kittmann
Materials Science
Multicomponent Materials
Doctoral researcher
M.Sc. Hanna Lewitz
Materials Science
Inorganic Functional Materials
Doctoral researcher
M.Sc. Jana Meyer
Materials Science
Micro-Manufacturing Processes
Doctoral researcher
M.Sc. Marc Alexander Nowak
Materials Science
Inorganic Functional Materials
Doctoral researcher

 

Role within the Collaborative Research Centre

The service project Z1 plays an important role within the framework of the CRC, as – together with Z2 – it acts as the interface between the project areas A and B. While the A projects pioneer new sensor concepts, the B projects implement the sensors in biomedical applications. The scientific work of the B projects relies on the availability of sufficiently large numbers of sensors with reliable and reproducible sensor characteris- tics. The researchers of Z1 will participate in the focus groups “Magnetic Layers” and “ME Sensors”. Collaborations with the following projects are planned:

Collaborations
A1 (Magnetostrictive Multilayers for Magnetoelectric Sensors) Providing partially-processed wafers and sensor templates for studies on magnetic multilayers; integration of new magnetic multilayers and powder-based permanent magnets.
A2 (Hybrid Magnetoelectric Sensors based on Mechanically Soft Composite Materials) Providing processes for piezoelectric and magnetostrictive functional layers as well as partially processed cantilevers exhibiting magnetostrictive layers and powder-based permanent magnets.
A4 (∆E-Effect Sensors) Supply of ∆E-effect sensors for comparison; technical consulting with respect to external fabrication, support in the realization of post-fabrication processes, esp. the magnetostrictive functional layer.
A5 (Piezotronic Magnetoelectric Composites) Providing partially-processed wafers, esp. piezoelectric and magnetostrictive functional layers for piezotronic magnetometers.
A6 (Microstructure and Structural Change of Magnetoelectric and Piezotronic Sensors) Advanced characterization of functional materials to improve fabrication technology and for identifi- cation of process real structure interrelations.
A7 (Electrically Modulated Magnetoelectric Sensors) Fabrication of converse ME effect sensors; support in miniaturization of the sensor concept.
A9 (Surface Acoustic Wave Magnetic Field Sensors) Partial processing of SAW sensor wafers as process module; implementation of full fabrication flow on 150 mm quartz wafers.
A10 (Magnetic Noise of Magnetoelectric Sensors) Providing ME sensor structures for research on magnetic noise modelling.
B1 (Sensor Noise Performance and Analogue System Design) Providing ME sensors in various concepts for studies on sensor noise performance, feedback regarding sensor performance.
B2 (Digital Signal Processing) Providing a sufficient number of ME sensors for studies on digital signal processing, feedback regarding sensor performance.
B7 (3D-Imaging of Magnetically Labelled Cells) Design and fabrication of resonant sensors for particle imaging; focus on miniaturization to improve resolution, feedback regarding sensor performance.
B9 (Magnetoelectric Sensors for Movement Detection and Analysis) Design and fabrication of resonant ME sensors for movement analysis, focus on tuning adjustment of the resonance frequency, feedback regarding sensor performance.
B10 (Magnetoelectric Sensor Systems for Cardiologic Applications) Providing a sufficient number of ME sensors for magnetocardiography.
Z2 (Magnetoelectric Sensor Characterization) Electronics assembly and characterization of ME sensors; feedback regarding sensor performance.
T1 (Transfer project – Individualized Deep Brain Stimulation) Fabrication of ME sensors.

 

Project-related Publications

J. Arbustini, J. Muñoz, H. Wang, E. Elzenheimer, J. Hoffmann, L. Thormählen, P. Hayes, F. Niekiel, H. Heidari, M. Höft, E. Quandt, G. Schmidt, A. Bahr: MEMS Magnetic Field Source for Frequency Conversion Approaches for ME Sensors, BMT2022 , Joint Annual Conference of the Austrian, German and Swiss Societies for Biomedical Engineering, 2022. 
M. T. Bodduluri , B.Gojdka , N.Wolff , L. Kienle , T. Lisec, F. Lofink: Article Investigation of Wafer-Level Fabricated Permanent Micromagnets for MEMS, Micromachines , no. 13, issue 5 , pp. 742, 2022.
J. M. Meyer, V. Schell, J. Su, S. Fichtner, E. Yarar, F. Niekiel, T. Giese, A. Kittmann, L. Thormählen, V. Lebedev, S. Moench, A. Žukauskaitė, E. Quandt, F. Lofink: Thin-Film-Based SAW Magnetic Field Sensors, Sensors, vol. 21, no. 24, 8166, 2021.
F. Niekiel, J. Su, M.T. Bodduluri, T. Lisec, L. Blohm, I. Pieper, B. Wagner, F. Lofink: Highly Sensitive MEMS Magnetic Field Sensors with Integrated Powder-Based Permanent Magnets, Sensors and Actuators A: Physical, vol. 297, 11560, 2019.
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.
S. B. Hrkac, C. T. Koops, M. Abes, C. Krywka, M. Müller, M. Burghammer, M. Sztucki, T. Dane, S. Kaps, Y. K. Mishra, R. Adelung, J. Schmalz, M. Gerken, E. Lage, C. Kirchhof, E. Quandt, O. M. Magnussen, B. M. Murphy: Tunable Strain in Magnetoelectric ZnO Microrod Composite Interfaces, ACS Appl. Mater. Interfaces, 9 (30), pp. 25571–25577 , 2017.