Low-Field Sensing and Compassing

NVE has developed some of the world’s most sensitive solid-state magnetic sensors, using one of two spintronic nanotechnology structures: Giant Magnetoresistors (GMR) and Spin-Dependent Tunnel (SDT) Junctions. Spintronic sensors are smaller, use less power and are far more sensitive than older solid-state magnetic technologies such as Hall-effect sensors and Anisotropic Magnetoresisitive (AMR) sensors.

Penny imaged with NVE sensor
Image of a penny by high-resolution eddy-current probe with an NVE spintronic sensor. Pixel resolution is 100 microns. (Courtesy of S. Smith and T. Dogaru, University of North Carolina-Charlotte.)
Low-field sensing applications include solid-state compasses, nondestructive evaluation, document validation including currency and credit cards, and magnetic imaging.

Spintronic solid-state compasses determine heading direction by using low-field sensors to measure the angle of the earth’s magnetic field. Spintronic compasses could enhance location-based services in cellphones and smartphones, and enable smaller, more precise, or more power-efficient navigation modules for consumer devices.

Nondestructive evaluation involves testing in place critical components such as airframes, bridges, or building structures. NVE has developed spintronic sensors that can locate defects such as small cracks by detecting very small perturbations in magnetic fields.