In Vivo Magnetic Recording of Neuronal Activity.

Neuronal activity generates ionic flows and thereby both magnetic fields and electric potential differences, i.e., voltages.

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

The electrical activity of brain, heart and skeletal muscles generates magnetic fields but these are recordable only macroscopically, such as in magnetoencephalography, which is used to map neuronal activity at the brain scale. At the local scale, magnetic fields recordings are still pending because of the lack of tools that can come in contact with living tissues. Here we present bio-compatible sensors based on Giant Magneto-Resistance (GMR) spin electronics.