Overview
Magnetic sensors are widely used in industry, for example, in automotive applications, information storage, metrology, medical devices, and IoT sensors. Our novel high-performing magnetic sensors have both ultra-detectability and high stability, and are inexpensive to manufacture. They also have low intrinsic noise, high temperature stability, low power consumption, DC to high frequency response, and low cross-field error.
Market Opportunity
Nearly all objects and systems around us generate a magnetic field that can be used to gain information about them. But the relatively low sensitivity of conventional magnetic sensors limits the information one can obtain. The availability of highly sensitive magnetic sensors would have wide use in the many applications involving weak magnetic fields.
Innovation and Meaningful Advantages
Traditional magnetic field sensors make use of the Hall effect: when a conducting material carrying current is in contact with a magnetic field, the electrons in the current are deflected perpendicular to their flow. The small perpendicular voltage that is created is used by Hall sensors to detect the presence of magnetic fields.
Fabricated with a cobalt-iron-boron film, our sensor is based on what is called the anomalous Hall effect (AHE), which arises in ferromagnetic materials. Instead of the charge of electrons, the AHE arises from electron spin, the tiny magnetic moment of each electron. The AHE causes electrons with different spins to disperse in different directions, giving rise to a detectable voltage. The electron spins can easily flip if the material encounters even a relatively weak external magnetic field, making the sensor extremely sensitive.
Our new magnetic sensor is compact and inexpensive to produce. It requires minimal power and is twenty times more sensitive than conventional sensors. Because the device is so small, millions of sensors could be placed on a single chip, enabling testing for multiple things at a time in a single sample. The sensors can work in a wide frequency range of DC to many MHz. The new sensors are ideally suited for high-end applications, for example, security scanning devices to detect counterfeit objects (currency, documents, etc.), scanning magnetic microscope for semiconductor or quantum chip diagnosis, non-invasive detection of subsurface activities, medical imaging and diagnosis, navigation and space applications, massive magnetic sensor arrays, magnetic spectrum analyzer, etc.
Collaboration Opportunity
We are interested in exploring 1) startup opportunities with investors; 2) research collaborations with leading companies to develop this technology as products and for high-end applications; and 3) licensing opportunities with companies.
Principal Investigator
Gang Xiao, PhD
Ford Foundation Professor of Physics
Professor of Engineering, Brown University
gang_xiao@brown.edu
IP Information
US Patent 11,500,042, Issued November 15, 2022
Publications
Wang, Kang, Yiou Zhang, and Gang Xiao. "Anomalous Hall sensors with high sensitivity and stability based on interlayer exchange-coupled magnetic thin films." Physical Review Applied 13, no. 6 (2020): 064009. doi: https://doi.org/10.1103/PhysRevApplied.13.064009
Contact
Victoria Campbell
Director of Business Development
victoria_campbell@brown.edu
Tech ID 3052