Giant Magnetic Resistivity or GMR effects
occur when ultra-thin magnetic structures are set in close proximity
to each other. Alternately magnetic and non-magnetic layers can
be built up with the magnetic fields either parallel or anti-parallel,
creating very sensitive low- to high-resistance components. While
development is currently in progress in the United States and Japan,
sensors based on GMR remain unavailable on the market.
This project was aimed at developing a
new type of GMR sensor for contactless measurement of the direction
of weak magnetic fields. Up to ten nano-thin magnetic layers are
sputter-deposited on a silicon wafer which is then removed, leaving
an instrument which can sense magnetic fields over a 360-degree
The generic nature of the sensor and its
very small dimensions make for a wide variety of potential applications,
promising increased activity and competitiveness for European manufacturers.
Initial applications are envisaged in the automotive industry, including
angle and position sensors, potentiometers and throttle control,
wheel speed, engine speed, and gear shaft position sensors, all
of which could help to improve driving safety. Other possible applications
are seen in the automation and medical sectors.