HIGH SENSITIVITY, PASSIVE MAGNETIC FIELD SENSOR AND METHOD OF MANUFACTURE
First Claim
1. A magnetic field sensor for sensing an applied magnetic field, the sensor comprising:
- a layer of magnetostrictive material having a magnetization vector that responds to the applied magnetic field by rotating in a plane and generating a stress;
a layer of electroactive material, mechanically bonded to the layer of magnetostrictive material, that responds to the stress by generating a voltage; and
electrodes that measure the voltage generated by the electroactive material in a direction substantially parallel to the plane in which the magnetization vector rotates.
1 Assignment
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Accused Products
Abstract
A magnetic field sensor comprises one or more magnetic layers of magnetostrictive material that is mechanically bonded to one or more layers of electroactive material. When a magnetic field is applied to the device, it rotates the magnetization that is present in the in the magnetostrictive material thereby generating a magnetostrictive stress in the material. The magnetostrictive stress generated by this layer, in turn, stresses the piezoelectric layer to which the magnetostrictive layer is bonded. In order to increase sensitivity, the voltage across the piezoelectric material is measured in a direction that is parallel to the plane in which the magnetization in the magnetic material rotates.
44 Citations
49 Claims
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1. A magnetic field sensor for sensing an applied magnetic field, the sensor comprising:
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a layer of magnetostrictive material having a magnetization vector that responds to the applied magnetic field by rotating in a plane and generating a stress; a layer of electroactive material, mechanically bonded to the layer of magnetostrictive material, that responds to the stress by generating a voltage; and electrodes that measure the voltage generated by the electroactive material in a direction substantially parallel to the plane in which the magnetization vector rotates. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A magnetic field sensor for sensing an external magnetic field, the sensor comprising:
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a layer of magnetostrictive material having a magnetization vector that responds to the applied magnetic field by rotating in a plane and generating a stress; a layer of electroactive material mechanically bonded to the layer of magnetostrictive material that responds to the stress by generating a voltage; and means for measuring the voltage generated by the electroactive material in a direction substantially parallel to the plane in which the magnetization vector rotates. - View Dependent Claims (28, 29, 30, 31)
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32-42. -42. (canceled)
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43. An apparatus that responds to an external magnetic field, the apparatus comprising:
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a layer of magnetostrictive material having a magnetization vector that responds to the magnetic field by rotating in response to the magnetic field and generating a magnetostrictive stress in a direction; a layer of electroactive material, mechanically bonded to the layer of magnetostrictive material, that responds to the magnetostrictive stress by generating a voltage; and electrodes across which appears the voltage generated by the electroactive material in a direction substantially parallel to the direction in which the principal magnetostrictive stress is generated. - View Dependent Claims (44, 45, 46, 47, 48, 49)
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Specification