SBIR/STTR Phase I:Flux-Gated Spin-Dependent-Tunneling Sensors

This Small Business Innovation Research (SBIR) Phase I project develops novel spin-dependent-tunneling (SDT) magnetic-field sensor devices based on innovative methods of flux modulation. The program identifies two modes of "flux gating" as a means of chopping or sweeping the magnetic field which is sensed by the SDT transducers. The flux gating methods are proposed as enhancements to the functionality of the already promising SDT magnetic sensor. The first method offers a low-power solution for increasing the SDT signal-to-noise ratio especially at low frequencies where 1/f noise is present. The second method enables the determination of absolute field magnitudes. Successful development of these novel ideas will lead to the advancement of small, solid-state, inexpensive, low-power, high resolution magnetic-field sensors. These sensors can be used discretely or in compact arrays for diverse applications including non-destructive evaluation of metallic structure flaws. The commercial applications of the research include non-destructive evaluation of flaws in metallic structures; detection, surveillance and tracking of magnetic or metallic objects; security systems; and magnetic media sensing-which includes currency evaluation and discrimination, and magnetic card readers.