Summary
UCLA researchers in the Department of Electrical Engineering have invented a novel magnetic sensor design that is highly sensitive and linear, with tunable response and low power consumption.
Background
Magnetic sensors have broad applications in fields such as automotive industry, medical application and hard disk drive read heads. Current magnetic sensor technologies focus on the issue of linear and reversible response of the sensor to the magnetic field. Existing solutions include perpendicular alignment of magnetization between the sensing and the reference layers, reducing the thickness of the sensing layer and introducing additional magnetization materials. These approaches render the sensor designs complicated, noisy, unscalable and insensitive. Novel solutions that improve upon these designs are highly desirable.
Innovation
A novel nanoscale linear magnetoresistance sensor was invented to address the aforementioned issues. This new design utilizes a structure called magnetic tunnel junctions between the sensor’s sensing and reference layers. The two layers exhibit in-plane magnetization and interfacial perpendicular anisotropy. These features attribute to the high sensitivity and linearity of the device response, and can be tuned by material thickness and DC bias voltage. Optionally, when constructed in a high resistance tunnel structure, a high-resistance sensor with ultralow power consumption can be achieved.
Applications
▶ Automotive sensors (position, speed, and rotation)
▶ Medical applications
▶ Hard disk drive read heads
▶ Sensor array or sensing circuits (Wheatstone bridge)
Advantages
▶ High sensitivity and linearity
▶ Tunable response
▶ Energy efficient