Tunnel-magnetoresistance sensors with sub-pT detectivity for detecting bio-magnetic fields
Tunnel-magnetoresistance (TMR) sensors based on magnetic tunnel junctions are emerging spintronic devices that are promising for applications to wearable bio-magnetic-field monitoring systems. Targeting bio-magnetic fields from the human heart and brain requires TMR sensors with sub-pT detectivity at frequencies of 1–1000 Hz. In this article, technical strategies for achieving such detectivity from the viewpoints of thin-film materials and sensor configurations are reviewed. Recent demonstrations of magnetocardiography and magnetoencephalography using our TMR sensors are also reviewed, and potentially effective techniques to further optimize detectivity are proposed.
Authors
- Mikihiko Oogane (ORCID: https://orcid.org/0000-0001-8056-2051)
- T. Nakano (ORCID: https://orcid.org/0000-0002-9451-0014)
- Kosuke Fujiwara (ORCID: https://orcid.org/0000-0002-7498-5688)
Institutions
- Tohoku University (JP)
- Spintronics Research Network of Japan (JP)
Publication Details
- Journal
- Applied Physics Letters
- Published
- 2025-04-21
- DOI
- https://doi.org/10.1063/5.0263879
- Citations
- 9
- Primary Topic
- Magnetic properties of thin films
- Type
- article
- Field-Weighted Citation Impact
- 11.22
Funders
- Ministry of Education, Culture, Sports, Science and Technology
- New Energy and Industrial Technology Development Organization
- Ministry of Economy, Trade and Industry