838 results about "Lorentz force" patented technology

A device for measuring a mechanical property of a tissue includes a probe configured to perturb the tissue with movement relative to a surface of the tissue, an actuator coupled to the probe to move the probe, a detector configured to measure a response of the tissue to the perturbation, and a controller coupled to the actuator and the detector. The controller drives the actuator using a stochastic sequence and determines the mechanical property of the tissue using the measured response received from the detector. The probe can be coupled to the tissue surface. The device can include a reference surface configured to contact the tissue surface. The probe may include a set of interchangeable heads, the set including a head for lateral movement of the probe and a head for perpendicular movement of the probe. The perturbation can include extension of the tissue with the probe or sliding the probe across the tissue surface and may also include indentation of the tissue with the probe. In some embodiments, the actuator includes a Lorentz force linear actuator. The mechanical property may be determined using non-linear stochastic system identification. The mechanical property may be indicative of, for example, tissue compliance and tissue elasticity. The device can further include a handle for manual application of the probe to the surface of the tissue and may include an accelerometer detecting an orientation of the probe. The device can be used to test skin tissue of an animal, plant tissue, such as fruit and vegetables, or any other biological tissue.

Magnetically and electromagnetically driven MEMS devices for reflecting light signals and for switching radio frequency (RF) signals are provided. In a preferred embodiment, a light reflecting device such as a mirror or micro-scanner comprises a plate operative to reflect light and at least two conductive flexural actuators connected to the plate and to a substrate and operative to impart a rotation or tilt motion to the plate under a force arising from the interaction of a current passing through the conductive flexural actuators and a magnetic field parallel to the substrate. An RF switch comprises a substrate and a membrane having a longitudinal dimension and a lateral dimension, the membrane positioned substantially parallel to and attached to the substrate and operative to provide at least two switching positions in response to actuation by a Lorenz force acting on it.

This invention discloses a haptic interface system that uses Lorentz forces to provide magnetic levitation for a handle which can be manipulated by a person, typically a computer user.

The present invention is directed to an inductively driven electromagnetic linear actuator arrangement employing eddy currents induced by a fixed drive coil to drive its armature. Eddy current focusing fields are employed to direct the eddy currents using Lorentz forces to maximize armature speed. The armature includes a shorted driven coil in a DC magnetic field. This can be supplied by a permanent magnet. When current is applied, a force is felt by the coil in a direction perpendicular to the magnetic field. Such an actuator is well suited for electrical switching applications including transfer switching applications, circuit breaker applications, and ground fault interrupter applications.

The invention discloses a large-torque magnetic suspension flywheel, which can be used as an execution mechanism for attitude stabilization and attitude maneuver of spacecrafts such as a satellite, an earth observation platform and the like. The magnetic suspension flywheel mainly consists of a base, a sealing cover, a radial decoupling conical magnetic bearing assembly, a core shaft, a rotor assembly, a Lorentz force magnetic bearing assembly, a motor assembly, a sensor assembly and the like. The core shaft is positioned in the center of the wheel body, a stator assembly is positioned at theradial outer side of the core shaft, the rotor assembly is arranged at the radial outer side of the stator assembly, the rotor assembly consists of a wheel flange and a wheel hub, and the Lorentz force magnetic bearing assembly consists of a magnetic bearing stator part and a magnetic bearing rotor part; an adapter plate is connected with the core shaft, the stator assembly and a motor stator; and the sensor assembly consists of a sensor shell and a sensor. The components of the flywheel are arranged reasonably and compactly, the flywheel can be used for attitude stabilization of the spacecraft, and attitude maneuver of the spacecraft can be realized by using large control torque provided by gyroscopic effect of the magnetic suspension flywheel.

The invention discloses a magneto-acoustic microscopic imaging method, comprising the steps of applying pulse excitation on a conductive target imaging body in a static magnetic field, generating an inductive vortex in the conductive target imaging body, and generating a Lorentz force by the interaction of the inductive vortex and the static magnetic field so as to cause the vibration of mass points in the imaging body to generate ultrasonic signals; receiving image signals of the ultrasonic signals of each mass point in the conductive target imaging body by using an array ultrasonic probe on a focal plane of an acoustic lens, imaging the received image signals of each mass point in the conductive target imaging body, so that each mass point image signal is proportional to the Lorentz force divergence of a corresponding point in the conductive target imaging body, and a Lorentz force divergence image of the conductive target imaging body or a reconstructed image according to current density rotation can be obtained according to the image signals of the ultrasonic signals detected by the array ultrasonic probe. A magneto-acoustic microscopic imaging system using the imaging method disclosed by the invention comprises a synchronous trigger and control module (1), an excitation source, an imaging system and a week signal detecting system.

A plurality of integrated electronic compasses and circuit system. The system includes a semiconductor substrate and one or more CMOS integrated circuits formed on one or more portions of the semiconductor substrate. The system has a plurality of electronic compass devices operably coupled to the one or more CMOS integrated circuits. The plurality of electronic compass devices can be integrated with one or more sensors, MEMS, or other devices.

An electromagnetic launcher comprising, an electric power supply, a conductive, stationary guide operatively connected to the power supply and forming a flowpath for current from the power supply, and a non-conductive projectile disposed adjacent to the guide and which is accelerated along the guide when current flows through the guide. The guide includes a plurality of conductive rails disposed in spaced, substantially parallel relation to each other, a plurality of conductive rungs interconnecting the rails and disposed in spaced relation to each other along the rails, and normally-open switches operatively associated with the rungs for selectively permitting current flow through different ones of the rungs. The projectile includes a main body and a magnet supported by the main body such that the magnet faces the guide with a small gap therebetween. The switches are passively activated only when they are disposed within a magnetic field of the projectile, such that the switches are sequentially activated as the projectile moves along the guide and create an electromagnetic pushing Lorentz force which continuously accelerates the projectile along the guide substantially in a direction parallel to the guide.

In an apparatus and method for magnetic field assisted electrochemical discharge machining (ECDM), the magneto hydrodynamic (MHD) effect is utilized to improve the thickness of bubble film and the electrolyte circulation so as to enhance the machining accuracy and efficiency. Since charged ions in a magnetic field are induced by Lorenz force to move, and the electrolysis bubbles generated in the ECDM process are suffused with electrification ions on their surfaces, the electrolysis bubbles can be forced to move in the direction of the magnetic field without the need of mechanical disturbance. The present invention can be widely applied in the micro-machining of non-conductive brittle materials of different dimensions and shapes, comprising the forming of microchannels and microholes on a biochip, and in the micro-opto-electro-mechanical system (MOEMS) and various kinds of micro-machining fields. The machined surface is smooth and does not require a second time machining.

A magnetic sensor utilizes a MEMS device that has at least one vibrating member and at least one conductive path integral with the vibrating member so that a current flows along the vibrating member and in the presence of a magnetic field interaction of the magnetic field and the point charges in the current on the conductive path due to the Lorentz force causes a change in vibration of the vibrating member. That change can be used to provide a measure of the magnetic field.

A system and a method of magnetosonic impedance imaging based on a lorentz force mechanic effect comprise an ultrasonic driving excitation source, an ultrasonic probe array, a control system, a magnet system, a direct current power supply and a signal detecting processing system. The ultrasonic probe array is in an emitting or measuring mode through the control system. The direct current power supply is in a connected or disconnected state through the control system so as to achieve two modes of exerting a magnetic field or withdrawing a magnetic field. Mass point vibration speed ratio under a magnetic field condition or a non-magnetic field condition is measured, and a conductivity image is rebuilt according to a square root of the vibration speed ratio. The imaging method does not require electric field measurement, only sound wave signals are required to be measured, a corresponding relation between measured signals and conductivity is simple and clear, and fast image rebuilding is facilitated.

The invention discloses an internal rotor magnetic suspension spherical surface gyro flywheel. The flywheel comprises a stationary part and a rotating part. The stationary part comprises an upper gyro chamber, a middle gyro chamber, a lower gyro chamber, a sealing ring, an axial spherical surface magnetic bearing stator, a protective bearing, a motor assembly stator, an axial displacement sensor assembly, a radial displacement sensor assembly, a radial spherical surface magnetic bearing stator and a Lorentz force magnetic bearing stator. The rotating part comprises a gyro outer rotating disk assembly, a gyro inner rotating shaft, sphere center adjusting backing rings and gyro rotor lock nuts. A spherical surface magnetic bearing is adopted to serve as supporting member, five-degree-of-freedom active suspension of the magnetic suspension gyro flywheel can be achieved, the interference of three times of translation control of a rotor in two times of radial twist control is eliminated, and then the moment precision of the high gyro moment instantly output by the gyro flywheel is increased.

The device includes a rolling bearing unit supporting a radial load and a magnetic bearing unit supporting an axial load and/or a bearing preload; an electromagnet fitted to a spindle housing so as to confront, on a non-contact basis, a flange shaped thrust plate mounted on a main shaft; a motor rotor of a motor for driving the shaft, and a motor stator opposed to the rotor, the shaft being driven by magnetic or Lorentz forces developed between the rotor and the stator; and a sensor detecting an axial force acting on the bearing unit, and a controller controlling the electromagnet. In this device, the stiffness of a composite spring formed by the bearing unit and a support system for the bearing unit is chosen to be higher than the negative stiffness of a composite spring of a motor part comprised of the electromagnet and the motor.

Device for separating, lifting and transporting sheets of aluminium or other non-ferromagnetic material consisting of a spider attraction assembly provided with a series of blocks of magnets and with contact electrodes, which by way of the effects produced by Lorentz forces, together with the action of a series of vacuum pads, is provided with the capacity to attract sheets of aluminium.

A magnetic field sensor employing a graphene sense layer, wherein the Lorentz force acting on charge carriers traveling through the sense layer causes a change in path of charge carriers traveling through the graphene layer. This change in path can be detected indicating the presence of a magnetic field. The sensor includes one or more gate electrodes that are separated from the graphene layer by a non-magnetic, electrically insulating material. The application of a gate voltage to the gate electrode alters the electrical resistance of the graphene layer and can be used to control the sensitivity and speed of the sensor.

MEMS magnetometers with optically transduced resonator displacement are described herein. Improved sensitivity, crosstalk reduction, and extended dynamic range may be achieved with devices including a deflectable resonator suspended from the support, a first grating extending from the support and disposed over the resonator, a pair of drive electrodes to drive an alternating current through the resonator, and a second grating in the resonator overlapping the first grating to form a multi-layer grating having apertures that vary dimensionally in response to deflection occurring as the resonator mechanically resonates in a plane parallel to the first grating in the presence of a magnetic field as a function of the Lorentz force resulting from the alternating current. A plurality of such multi-layer gratings may be disposed across a length of the resonator to provide greater dynamic range and/or accommodate fabrication tolerances.