Abstract: A microelectromechanical modulating magnetic sensor comprising a base; a magnetic transducer associated with the base that provides an output in response to a magnetic field; a pair of movable flux concentrators positioned to move relative to the magnetic transducer; the pair of movable flux concentrators having a region of high flux concentration between the pair of movable flux concentrators; the pair of flux concentrators moving together in tandem with the distance between the pair remaining substantially constant during movement; support structure for supporting the pair of movable flux concentrators; a power source for causing the movable flux concentrators to move at a frequency within a predetermined frequency range; whereby when the pair of movable flux concentrators is in a first position the region of high flux concentration is in a first location, and when the pair of movable flux concentrators is in a second position, the region of high flux concentration is in a second position; such that as the

Abstract: A microelectromechanical modulating magnetic device comprising: a base; a magnetic transducer that provides an output in response to a magnetic field associated with the base; at least one movable flux concentrator positioned to move relative to the magnetic transducer; at least one flux collector positioned to collect flux for transfer onto at least one movable flux concentrator; which transfers the magnetic flux to the magnetic transducer for detection and measurement purposes; support structure for enabling the at least one movable flux concentrators to move within a predetermined frequency range; a power source for causing the movable flux concentrators to move at a frequency within the predetermined frequency range; whereby magnetic flux may enter through the flux collector, pass through the at least one movable flux concentrator for transfer to the magnetic transducer, and due to the movement of the movable flux concentrator, the signal outputted from the transducer is modulated.

Abstract: A ferromagnetic object is located by moving magnetic sensors along a path in an area of detection; using the sensors to measure a total magnetic field in the area of detection; using the sensors to measure all three vector components of magnetic field as the sensors travel along the path and passes the object; computing theoretical vector components of the total magnetic field in the area of detection; matching the measured vector components with the computed theoretical vector components of the total magnetic field; calculating an error measurement between matched measured vector components and computed theoretical vector components of the magnetic field; determining optimized values of parameters that minimize an error between the measured vector components and computed theoretical vector components of the magnetic field; and determining a position of the object based on the measured components of the magnetic field as a function of the optimized values.

Abstract: A microelectromechanical modulating magnetic sensor comprising a base; a magnetic transducer associated with the base that provides an output in response to a magnetic field; a pair of movable flux concentrators positioned to move relative to the magnetic transducer; the pair of movable flux concentrators having a region of high flux concentration between the pair of movable flux concentrators; the pair of flux concentrators moving together in tandem with the distance between the pair remaining substantially constant during movement; support structure for supporting the pair of movable flux concentrators; a power source for causing the movable flux concentrators to move at a frequency within a predetermined frequency range; whereby when the pair of movable flux concentrators is in a first position the region of high flux concentration is in a first location, and when the pair of movable flux concentrators is in a second position, the region of high flux concentration is in a second position; such that as the

Abstract: A MEMS device and method comprising a MEMS structure adjacent to a SOI base; a sacrificial support operatively connecting the base to the MEMS structure; a suspension member operatively connecting the base to the MEMS structure, wherein the suspension member is longer than the sacrificial support; and an electrode operatively connected to the base. The device may further comprise a current pulse generator adapted to send a current pulse through the sacrificial support, wherein the current pulse causes the sacrificial support to detach from the MEMS structure. Moreover, the sacrificial support structures may be electrically resistive.

Abstract: A technique for locating stationary magnetic objects comprises placing magnetic sensors on a movable platform; for each sensor, measuring a total magnetic field signal in an area of detection; using the sensors to identify a line upon which a target stationary magnetic object is located; and fixing a location of the object by moving the platform in substantially straight lines until the object is detected by at least two of the sensors; using the measured signals to determine a first path on which the object lies; positioning the sensors so that a line connecting two of the sensors intersects the first path on which the object lies; moving the platform along a second path substantially parallel to the first path; recording two positions at which at least two of the sensors detect a maximum total magnetic field signal from the object; and identifying a third path through the two positions.

Abstract: A technique for locating stationary magnetic objects comprises placing magnetic sensors on a movable platform; for each sensor, measuring a total magnetic field signal in an area of detection; using the sensors to identify a line upon which a target stationary magnetic object is located; and fixing a location of the object by moving the platform in substantially straight lines until the object is detected by at least two of the sensors; using the measured signals to determine a first path on which the object lies; positioning the sensors so that a line connecting two of the sensors intersects the first path on which the object lies; moving the platform along a second path substantially parallel to the first path; recording two positions at which at least two of the sensors detect a maximum total magnetic field signal from the object; and identifying a third path through the two positions.

Abstract: A ferromagnetic object is located by moving magnetic sensors along a path in an area of detection; using the sensors to measure a total magnetic field in the area of detection; using the sensors to measure all three vector components of magnetic field as the sensors travel along the path and passes the object; computing theoretical vector components of the total magnetic field in the area of detection; matching the measured vector components with the computed theoretical vector components of the total magnetic field; calculating an error measurement between matched measured vector components and computed theoretical vector components of the magnetic field; determining optimized values of parameters that minimize an error between the measured vector components and computed theoretical vector components of the magnetic field; and determining a position of the object based on the measured components of the magnetic field as a function of the optimized values.

Abstract: A planer reader and method of probing the magnetic permeability of a material using a magnetic flux circuit comprises a substrate; a near-circular soft magnetic layer adjacent to the substrate; a gap configured in the soft magnetic layer, wherein the gap creates an opening between two ends of the soft magnetic layer, and wherein the gap is configured to align with a material located a distance from the soft magnetic layer; a magnetic flux generator adapted to provide magnetic flux to the material; and a magnetic sensor adapted to measure the magnetic flux traversing the material. The circuit further comprises an insulator covering the soft magnetic layer, the gap, the magnetic flux generator, and the magnetic sensor. The magnetic flux generator comprises a magnet or a magnetic coil proximate to the soft magnetic layer. Moreover, the soft magnetic layer comprises a soft ferromagnet. In one embodiment, the substrate is flexible.

Abstract: A method of fabricating a MEMS device includes forming a magnetic sensor over a SOI wafer which may include an epoxy layer; forming a pair of MEMS flux concentrators sandwiching the magnetic sensor; connecting an electrostatic comb drive to each of the flux concentrators; connecting a spring to the flux concentrators and the comb drive; performing a plurality of DRIE processes on the SOI wafer; and releasing the flux concentrators, the comb drive, and the spring from the SOI wafer. Another embodiment includes forming adhesive bumps and a magnetic sensor on a first wafer; forming a second wafer; forming a pair of MEMS flux concentrators, a pair of electrostatic comb drives, and at least one spring on the second wafer; bonding the second wafer to the adhesive bumps; and compressing the adhesive bumps using non-thermal means such as pressure only.

Abstract: A MEMS device and method of manufacturing comprises a magnetic sensor attached to a frame; at least one magnet adjacent to the magnetic sensor; a proof mass attached to the magnet; a cantilever beam attached to the proof mass; and a rod attached to the cantilever beam and the frame, wherein the magnet is adapted to rotate about a longitudinal axis of the rod. The proof mass comprises a portion of a SOI wafer. An acceleration of the frame causes the magnet to move relative to the frame and the magnetic sensor. An acceleration of the frame causes the connecting member to bend. The motion of the magnet causes a change in a magnetic field at a position of the magnetic sensor, wherein the change in the magnetic field is detected by the magnetic sensor, and wherein a sensitivity of detection of the acceleration of the device is approximately 0.0001 g.

Abstract: A microelectromechanical system (MEMS) device comprising a base structure; a magnetic sensor attached to the base structure and operable for sensing a magnetic field and allowing for a continuous variation of an amplification of the magnetic field at a position at the magnetic sensor; and for receiving a DC voltage and an AC modulation voltage in the MEMS device; a pair of flux concentrators attached to the magnetic sensor; and a pair of electrostatic comb drives, each coupled to a respective flux concentrator such that when the pair of electrostatic comb drives are excited by a modulating electrical signal, each flux concentrator oscillates linearly at a prescribed frequency; and a pair of bias members (mechanical spring connectors) connecting the flux concentrators to one another.

Abstract: An apparatus, system, and method for probing magnetic permeability of a material located a distance from the apparatus comprises a first hard ferromagnetic layer, a second hard ferromagnetic layer, a first soft ferromagnetic layer, a second soft ferromagnetic layer, an intermediate layer disposed between the first hard ferromagnetic layer and the first soft ferromagnetic layer, an insulating layer between the first soft ferromagnetic layer and second soft ferromagnetic layer, and a spacer layer disposed between the second soft ferromagnetic layer and the second hard ferromagnetic layer, wherein the second soft ferromagnetic layer increases an on/off ratio of a magnetic field in the first soft ferromagnetic layer, wherein the on/off ratio is approximately 1.6, and wherein the second soft ferromagnetic layer pulls a magnetic field of the apparatus into the first soft ferromagnetic layer.

Abstract: Systems and methods for probing the magnetic permeability of a material are disclosed. A sensor unit can be configured to comprise magnet layers thereof, including a soft ferromagnetic layer, a first hard ferromagnetic layer and a second hard ferromagnetic layer. An intermediate layer (e.g., conductor or insulator) can be disposed between the first hard ferromagnetic layer and the soft ferromagnetic layer within the sensor unit. Additionally, a spacer layer can be disposed between the soft ferromagnetic layer and the second hard ferromagnetic layer, wherein the sensor unit measures the magnetic properties of a material located a distance from the sensor unit through the magnetic interaction of the magnetic layers of the sensor unit. Conduction between the first hard ferromagnetic layer and the soft ferromagnetic layer generally occurs via tunneling.

Abstract: Methods and systems for tracking a magnetic object are disclosed. A plurality of line segments can be complied based on data received from a plurality of magnetic sensors. The line segment that minimizes an error thereof can then be determined. The path of a magnetic object can then be established based on the compiled line segments and calculated error thereof, thereby permitting the magnetic object to be tracked according to the data received from the magnetic sensors, which can be based on the closest of approach of one or more of the magnetic sensors to the magnetic object. The present invention can thus permit a magnetic object to be tracked utilizing the total magnetic field measured at a position of closest approach by the magnetic object to one or more magnetic sensors from among a group of magnetic sensors.

Abstract: A magnetic sensing transducer device that senses low frequency magnetic fields by using flux concentrators that modulate the observed low frequency signal, thereby shifting this observed signal to higher frequencies and minimizing 1/f-type noise. This is accomplished by the oscillatory motion of a microelectromechanical (MEMS)-type magnetic flux concentrator operated with a magnetic sensor, preferably made on a common substrate. Such a combined device can be used in a magnetometer. Such a device is small, low-cost and has low-power-consumption requirements. The magnetic sensor can be a Hall effect or other type of magnetic sensor. At least one MEMS-type fabricated flux concentrator is used with the magnetic sensor. The concentrator oscillates at a modulation frequency much greater than the observed magnetic field being sensed by the device.

Abstract: A magnetic sensing device that senses low frequency magnetic fields by using movable flux concentrators that modulate the observed low frequency signal. The concentrator oscillates at a modulation frequency much greater than the observed magnetic field being sensed by the device. The modulation shifts this observed signal to higher frequencies and thus minimizes 1/f-type noise. This is preferably accomplished by the oscillatory motion of a microelectromechanical (MEMS)—type magnetic flux concentrator operated with a magnetic sensor, preferably made on a common substrate. Such a combined device can be used in a magnetometer. Such a device is small, low-cost and has low-power-consumption requirements. The magnetic sensor can be a Hall effect or other type of magnetic sensor. At least one modulating flux concentrator is used with the magnetic sensor.

Abstract: A debonding layer is formed on fibers such as silicon carbide fibers by forming a thin film of a metal such as nickel or iron on the silicon carbide fibers and then annealing at a temperature of about 350-550° C. to form a debond layer of a metal silicide and carbon. These fibers having the debond coating can be added to composite forming materials and the mixture treated to form a consolidated composite. A one heating-step method to form a consolidated composite involves inserting the silicon carbide fibers with just the initial metal film coating into the composite forming materials and then heating the mixture to form the debond coating in situ on the fibers and to form the consolidated composite. Preferred heating techniques include high temperature annealing, hot-pressing, or hot isostatic pressing (HIP).

Abstract: A debonding layer is formed on fibers such as silicon carbide fibers by fing a thin film of a metal such as nickel or iron on the silicon carbide fibers and then annealing at a temperature of about 350-550.degree. C. to form a debond layer of a metal silicide and carbon. These fibers having the debond coating can be added to composite forming materials and the mixture treated to form a consolidated composite. A one heating-step method to form a consolidated composite involves inserting the silicon carbide fibers with just the initial metal film coating into the composite forming materials and then heating the mixture to form the debond coating in situ on the fibers and to form the consolidated composite. Preferred heating techniques include high temperature annealing, hot-pressing, or hot isostatic pressing (HIP).

Abstract: Filamentous substrates are coated with diamond by a chemical vapor deposition process. The substrate may then be etched away to form a diamond filament, such as a diamond tube or a diamond fiber. In a preferred embodiment, the substrate is copper-coated graphite. The copper initially passivates the graphite, permitting diamond nucleation thereon. As deposition continues, the copper-coated graphite is etched away by the active hydrogen used in the deposition process. As a result a substrate-less diamond fiber is formed. Diamond-coated and diamond filaments are useful as reinforcement materials for composites, is filtration media in chemical and purification processes, in biomedical applications as probes and medicinal dispensers, and in such esoteric areas as chaff media for jamming RF frequencies.