The detection of magnetic field distributions in the region of the head or torso allows for powerful diagnosis practices of brain (magnetoencephalography MEG) or heart (magnetocardiography MCG) functions. Systems used as routine diagnostic tools need to be easy-to-handle and cost-effective, thus operation at room temperature is desirable. Magnetic field sensors based on miniaturized magnetoelectric composites, i.e. composites consisting of at least one magnetostrictive and one piezoelectric constituent, have revealed their potential to detect sub-pT fields at room temperature under certain conditions.
The general objectives of the Collaborative Research Centre CRC 1261 are the research and development of different magnetoelectric sensor approaches with a special focus on high sensitivity at biomagnetic frequencies (Project Area A) and their evaluation and utilization in medically relevant questions (Project Area B). The research program to pursue these goals requires intensive interdisciplinary collaboration between materials scientists, electrical engineers and physicians (neurology and cardiology). It will be supported by two cross-topical projects on micro-/nanosystem fabrication and on biomagnetic measurement techniques. An Integrated Research Training Group will be established with the intent of fostering interdisciplinary collaboration within the CRC 1261. Furthermore, a Scientific Outreach Project will be responsible not only for outreach to the public, students and teachers, but also for communicating in a scientific manner to young scientists.
Project area A, entitled Sensor Technology, covers research from new materials (A1, A2) to development of special sensor elements (A3) to the investigation of different magnetoelectric sensor approaches [ΔE-effect (A4), piezotronic read-out (A5, A6) and electrically modulated sensors (A7)]. All projects that focus on improving the detection limit at biomagnetically relevant frequencies will be supported by modeling (A8). The modeling project is linked closely to the modeling activities in project area B. This area B, entitled Sensor Systems for Medical Applications, includes signal processing (B1, B2), the solution of the inverse problem (B3) and selected application areas in cardiology, neurology and life sciences, which have different detection requirements in magnetic field strength, frequency and spatial resolution (B5, B6, B7).
The overarching aim of the CRC 1261 is the establishment of a biomagnetic diagnostics system based on magnetoelectric sensors for MEG and MCG, respectively, and to demonstrate its potential on selected medical diagnosis problems. The goals of the three funding periods are grouped on the basis of the predicted limits of Collaborative detection of the magnetoelectric sensors at biomagnetically relevant frequencies. Accordingly, the first period will focus on signals from the heart, nerves, deep brain stimulation and magnetically marked cells. In the second funding period, the medical application will be extended to natural neuronal signals, with special focus on reducing the cross-sensitivity to magnetic noise, thus allowing unshielded biomagnetic measurements. The objective of the final period is achieving a closed-loop system of measurement and immediate actuation. Uncooled magnetoelectric sensor arrays may then be implemented as a wearable device. A promising strategy is that measured data are processed in real time to drive actuators. For example, MEG data of current brain activity could be used to continuously adjust deep brain stimulation.