Magnetic field sensor using microelectromechanical system
AssigneeRockwell Automation Technologies, Inc.
InventorsRobert J. Kretschmann, Richard D. Harris
Life of this patent
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Abstract
A microelectromechanical systems (MEMS) Device manufactured on a microscopic scale using integrated circuit techniques provides a sensitive magnetic field sensor by detecting motion caused by the Lorentz force produced by a current through a MEMS conductor. The resulting MEMS may be used as a component in a variety of devices including current sensors and proximity sensors.
Claims50
A microelectromechanical system (MEMS) sensor providing magnetic field measurement, the sensor comprising:
- a substrate supporting a first and second terminal;
- a flexible conductor extending between the first and second terminals and positionable within a crossing magnetic field, the flexible conductor providing a path of conduction of a substantially constant current between the first and second terminals;
- a beam connected to the flexible conductor for communication of displacement of the flexible conductor;
- and
- a detector connected to the beam for detecting the Lorentz force deflection of the flexible conductor, the detector generating an output signal dependent on this force and thus on the strength of the crossing magnetic field,
- wherein at least a portion of the beam is insulating to electrically isolate the detector from the flexible conductor.
A method of sensing a magnetic field using a microelectromechanical system (MEMS) comprising the steps of:
- positioning a flexible MEMS conductor between a first and second terminal within a crossing magnetic field;
- applying a proof current to the flexible MEMS conductor to generate a Lorentz force on the flexible conductor;
- employing a beam connecting the flexible conductor to a detector for communication of displacement of the flexible conductor to the detector, wherein the beam includes an insulating portion;
- and
- detecting Lorentz force induced deflection of the flexible MEMS conductor to generate an output signal dependent on the Lorentz force and thus on the strength of the crossing magnetic field.
A microelectromechanical system (MEMS) sensor providing magnetic field measurement, the sensor comprising:
- a substrate supporting a set of pylons;
- a beam supported above the substrate by at least two pairs of opposing flexible arms extending transversely to the pylons on opposites sides of the beam;
- a flexible conductor supported by one pair of opposing flexible arms extending between first and second terminals on corresponding opposed pylons, the flexible conductor positionable within a crossing magnetic field to provide a path of conduction of a current between the first and second terminals;
- an actuator device communicating with the flexible conductor via the beam to provides a biasing force against a Lorentz force acting on the flexible conductor, and
- a detector communicating with the actuator for detecting the biasing force.
Dependencies are inferred from the claim text.