Local recording of biological magnetic fields using Giant Magneto Resistance-based micro-probes

Area of Science:

• Biophysics
• Neuroscience
• Biotechnology

Background:

• Electrical activity in the brain, heart, and muscles generates magnetic fields, typically recorded macroscopically (e.g., magnetoencephalography).
• Local-scale magnetic field recordings from living tissues are limited by the lack of suitable tools for direct contact.
• Existing technologies primarily focus on macroscopic measurements, leaving a gap in understanding localized bio-magnetic phenomena.

Purpose of the Study:

• To introduce novel, biocompatible sensors based on Giant Magneto-Resistance (GMR) spin electronics for local magnetic field recordings.
• To demonstrate the capability of GMR sensors to record magnetic fields from action potentials at the local scale in living tissues.
• To establish GMR technology as a potential counterpart to microelectrodes in electrophysiology for magnetophysiology.

Main Methods:

• Development and application of biocompatible Giant Magneto-Resistance (GMR) spin electronic sensors.
• In vitro experiments on mouse muscle tissue.
• Simultaneous recordings of magnetic fields and electrophysiology.
• Computational modeling to analyze recorded data.

Main Results:

• Successful demonstration of simultaneous local recordings of magnetic fields from action potentials using GMR sensors.
• The sensitivity of GMR sensors is largely independent of their size, facilitating miniaturization.
• Validation of the technology's potential for in vivo and in vitro magnetophysiology.

Conclusions:

• GMR-based sensors offer a new fundamental tool for investigating local neuronal magnetic activity.
• This technology bridges the gap in local-scale bio-magnetic field recordings.
• GMR sensors can serve as the magnetic analog to microelectrodes, advancing magnetophysiology research.