Spin-Dependent-Tunneling Sensors for Vehicle Detection

Period of Performance: 12/22/1999 - 12/24/2000


Phase 1 SBIR

Recipient Firm

Nonvolatile Electronics, Inc.
11409 Valley View Road Array
Eden Prairie, MN 55344
Principal Investigator

Research Topics


The proposal is to develop and evaluate new spin-dependent-tunneling (SDT) sensors as a low-power, low-cost, microelectronics-based technology for the detection of magnetic fields produced by objects such as military or commercial vehicles. Early SDT devices have shown good low field sensitivity at high frequencies, but exhibit a significant "1/f"-type noise at low frequencies. This program will address two approaches towards reducing the low-frequency noise: (1) Improvements in materials and fundamental sensor design issues that ultimately affect the intrinsic noise of the junction. (2) Innovative combinations of known electronics solutions for filtering noise and establishing a mode of operation which maximizes the signal-to-noise specific to the SDT devices. The program will use the electronics as a noise testing platform for quantitatively evaluating and comparing the sensor designs. After follow-on Phase II work, the optimized electronics will ultimately be integrated with the sensor on the same chip. BENEFITS: Commercial applications for these SDT ultra-low field sensors include: geomagnetics work, landmine and unexploded ordinance detection, digital switch devices, currency detection sensors, two and three-axis compasses, rotary encoders, surveillance and vehicle detection or monitoring, automotive manufacturing markets (gear tooth, wheel speed, crankshaft, and cylinder position sensing), nondestructive evaluation of metallic structures, bio-medical applications such as biochemical assaying, and standard current sensors (for utility and circuit board applications).