Magnetic field sensors and sensing methods are provided. A magnetic sensor module is configured to measure a magnetic field whose magnitude oscillates between a first extrema and a second extrema. The magnetic sensor module includes a magnetic sensor configured to generate measurement values in response to sensing the magnetic field, and a sensor circuit. The sensor circuit is configured to generate a measurement signal based on the measurement values, adjust an offset of the measurement signal according to an offset update algorithm and a first characteristic of the measurement signal, generate a pulsed output signal having pulses that are generated based on the adjusted measurement signal crossing the switching threshold, and selectively enable and disable the offset update algorithm based on a second characteristic of the measurement signal.

A system for determining a stuck point of a pipe positioned within a wellbore includes a tubular housing and a sensor array positioned within the tubular housing. The system also includes ferromagnetic flux collectors and flux concentrators on either side of the sensor array. The flux collectors collect a magnetic flux that has been written to a portion of pipe. The flux concentrators intensify the flux to improve measurements of the flux that are acquired by the sensor array.

A system for determining a stuck point of a pipe positioned within a wellbore includes a tubular housing and a sensor array positioned within the tubular housing. The system also includes ferromagnetic flux collectors and flux concentrators on either side of the sensor array. The flux collectors collect a magnetic flux that has been written to a portion of pipe. The flux concentrators intensify the flux to improve measurements of the flux that are acquired by the sensor array.

Disclosed methods include placing a semiconductor wafer containing MRAM devices into a first magnetic field that has a magnitude sufficient to magnetically polarize MRAM bits and has a substantially uniform field strength and direction over the entire area of the wafer. The method further includes placing the wafer in a second magnetic field having an opposite field direction, a substantially uniform field strength and direction over the entire area of the wafer, and magnitude less than a design threshold for MRAM bit magnetization reversal. The method further includes determining a presence of malfunctioning MRAM bits by determining that such malfunctioning MRAM bits have a magnetic polarization that was reversed due to exposure to the second magnetic field. Malfunctioning MRAM bits may further be characterized by electrically reading data bits, or by using a chip probe to read one or more of voltage, current, resistances, etc., of the MRAM devices.

A method for autonomously assembling a plurality of tiles is performed in a microgravity environment. Each tile includes a shell having a first geometrical shape and an arrangement of first magnets and a controller that are supported by the shell. The controller controls operation of the arrangement of first magnets to self-assemble the shell with another tile. The first magnets are controlled to mate with a complementary arrangement of second magnets on the other tile when the complementary arrangement of second magnets floats to within a range of magnetic attractive force of the arrangement of first magnets, with or without the aid of propulsion. The controllers in the tiles detect the status of the magnetic bonds to determine whether each pair of tiles is properly bonded or has a magnetic bond error. When an error is detected, the tiles are controlled to disassemble and reassemble to correct the error.

An electromechanical sensor and a method of sensing an object or a tactile input using the sensor. The sensor includes: a base provided with a magnetic sensor arranged to detect a change in magnetic flux at the position of the magnetic sensor; a flexible film adjacent to the magnetic sensor; and a magnetic element provided on the flexible film; wherein the magnetic element is arranged to move relative to the magnetic sensor when the flexible film is reversibly deformed by an external force applied to the flexible film.

A sensing system, and method of operating same, can act as a highly sensitive gradiometer. A first non-magnetic element, such as a sphere, is driven at a first resonance frequency along an axis. A magnet is attached to a second non-magnetic element, such as a plate, and driven at a second resonance frequency along the axis. The first non-magnetic element and the second non-magnetic element are coupled by a force along the axis, in resonance. The gradiometer is configured to determine a gradient magnetic field acting on one or more of the first non-magnetic element and magnet based on change in at least one resonance characteristic.

A system and method of effectively measuring a change in a gradient of a magnetic field. The systems include a first magnet and a second magnet mechanically coupled together and aligned along a polarization axis. The first magnet and the second magnet are positioned such that a pair of like magnetic poles of the first magnet and the second magnet face in opposite directions. Further, the first magnet and the second magnet are configured to move along the polarization axis in response to a magnetic field. A sensing system is configured to measure a change in a gradient of the magnetic field based on the movement of the first magnet and second magnet along the polarization axis in response to the magnetic field.

A system and method of effectively measuring a change in a gradient of a magnetic field. The systems include a first magnet and a second magnet mechanically coupled together and aligned along a polarization axis. The first magnet and the second magnet are positioned such that a pair of like magnetic poles of the first magnet and the second magnet face in opposite directions. Further, the first magnet and the second magnet are configured to move along the polarization axis in response to a magnetic field. A sensing system is configured to measure a change in a gradient of the magnetic field based on the movement of the first magnet and second magnet along the polarization axis in response to the magnetic field.

A gradiometer includes a at least one magnet attached to a beam. The magnet moves in response to a magnetic force. A sensing element is configured to measure movement or deflection of the beam or magnet. The gradiometer is configured to determine a gradient of a magnetic field acting on the first magnet based on movement of the magnet. The gradiometer can further measure higher order gradients.