87results about "Magnetostrictive device details" patented technology

An MTJ in an MRAM array or in a TMR read head is comprised of a capping layer with a lower inter-diffusion barrier layer, an intermediate oxygen gettering layer, and an upper metal layer that contacts a top conductor. The composite capping layer is especially useful with a moderate spin polarization free layer such as a NiFe layer with a Fe content of about 17.5 to 20 atomic %. The capping layer preferably has a Ru / Ta / Ru configuration in which the lower Ru layer is about 10 to 30 Angstroms thick and the Ta layer is about 30 Angstroms thick. As a result, a high dR / R of about 40% is achieved with low magnetostriction less than about 1.0 E−6 in an MTJ in an MRAM array. Best results are obtained with an AlOx tunnel barrier layer formed by an in-situ ROX process on an 8 to 10 Angstrom thick Al layer.

The invention describes rolled electroactive polymer devices. The invention also describes employment of these devices in a wide array of applications and methods for their fabrication. A rolled electroactive polymer device converts between electrical and mechanical energy; and includes a rolled electroactive polymer and at least two electrodes to provide the mechanical / electrical energy conversion. Prestrain is typically applied to the polymer. In one embodiment, a rolled electroactive polymer device employs a mechanism, such as a spring, that provides a force to prestrain the polymer. Since prestrain improves mechanical / electrical energy conversion for many electroactive polymers, the mechanism thus improves performance of the rolled electroactive polymer device.

The invention ris an actuating drive for deflecting an actuating element by a solid body actuator (2) which, when an electrical voltage or an alternating magnetic field is applied, experiences a length change. A housing (1) encloses the solid body actuator to define an interspace (13) in a fluid-tight manner. Furthermore, the solid body actuator includes a hollow duct (6) having one end connected to a first hollow conduit (20) passing through the housing and the other end opening into the interspace. The interspace is additionally connected in a fluid-tight manner to a second hollow conduit (21) passing through the housing.

Ultrasound for use in promoting a chemical reaction is generated by an electromagnet formed from a pair of magnetostrictive prongs wound with coils that are oriented to produce an oscillating magnetostrictive force when an oscillating voltage is applied, in conjunction with a sensing electromagnet of magnetostrictive material that is arranged to receive the vibrations generated by the driving electromagnet and produce internal magnetic field changes due to the reverse magnetostrictive effect. These field changes generate voltages that are representative of the amplitude of the oscillating magnetostrictive force. The generated voltage is compared to a target value in a control circuit that adjusts the applied oscillating voltage accordingly. The oscillations in the prongs of the electromagnet are transmitted to an ultrasonic horn that is immersed in the reaction medium to provide direct contact with the reaction mixture.

Systems and methods for flaw detection and monitoring at elevated temperatures with wireless communication using surface embedded, monolithically integrated, thin-film, magnetically actuated sensors, and methods for fabricating the sensors. The sensor is a monolithically integrated, multi-layered (nano-composite), thin-film sensor structure that incorporates a thin-film, multi-layer magnetostrictive element, a thin-film electrically insulating or dielectric layer, and a thin-film activating layer such as a planar coil. The method for manufacturing the multi-layered, thin-film sensor structure as described above, utilizes a variety of factors that allow for optimization of sensor characteristics for application to specific structures and in specific environments. The system and method integrating the multi-layered, thin-film sensor structure as described above, further utilizes wireless connectivity to the sensor to allow the sensor to be mounted on moving components within the monitored assembly.

Existing magnetoelectric materials relying on the use of metallic or ceramic magnetostrictive materials and ceramic piezoelectric materials as their constituent phases may have three problems. First, the operational frequency may be limited to a few kilohertz due to the presence of eddy-current losses in the metallic magnetostrictive phase. Secondly, it may be difficult to machine and fabricate devices due to the mechanical brittleness of the ceramic and some metallic magnetostrictive phases as well as of the ceramic piezoelectric phase. Thirdly, it may be difficult to tailor and optimize the properties (i.e., magnetoelectric voltage coefficient αE, etc.) of the devices due to the limitation of the types of the constituent materials. This invention provides a magnetoelectric element including at least one set of alternative piezoelectric layer and magnetostrictive composite layer. The magnetostrictive composite layer includes at least one magnetostrictive material dispersed in first concentrated zones within a first polymer matrix, wherein all of said concentrated zones are orientated along a first direction. It is found that the conversion efficiency (i.e., αE) varies in accordance with applied magnetic control field Hcontrol in magnetoelectric devices made of such a magnetoelectric element.

The invention relates to a circuit arrangement for the dynamic control of ceramic solid-state actuators, such as piezotranslators with energy recovery by means of magnetic intermediate stores and / or storage capacitors as well as by clocked switches. For achieving a predetermined linear voltage characteristic at the piezotranslator, according to the invention, a single inductive intermediate store is arranged in the secondary circuit, which is connected in series with the piezotranslator, and the secondary circuit is designed as a half-bridge. The switches provided in the respective half-bridge are controlled at a high cycle or switching frequency by an external controller, with the series connection of piezotranslator and inductive intermediate store furthermore carrying a superimposed bridge direct current in order to ensure the desired charging of the capacitance of the piezotranslator, on the one hand, and to optimize the energy recovery, on the other hand.

A piezoelectric resonator include a multi-layer top electrode. The multi-layer top electrode includes at least a top metal layer and a bottom metal layer. A top metal layer edge is recessed compared to a bottom metal layer edge allowing conformal deposition of a passivation layer. The passivation layer covers and protects the underlying layers from subsequent etching, thereby preventing etch undercut of the top electrode. In some embodiments, the multi-layer top electrode is configured as a bi-layer. In other embodiments, an extra layer is configured between the top metal layer and the bottom metal layer, for example a shunt load layer.

A driver circuit for generating a driving pulse signal to activate a vibrating element includes a half-bridge circuit formed essentially of first and second switching devices to which drive signals are supplied through a driver interface. A driving voltage is supplied to a source of the first switching device, a drain of the second switching device is grounded, and an output terminal of the half-bridge circuit is connected to the vibrating element. The half-bridge circuit is controlled such that the two switching devices alternately turn ON. When the first switching device is ON, the driving voltage is supplied as the driving pulse signal to the vibrating element, and when the second switching device is ON, the vibrating element and the second switching device together form a low-impedance closed loop. As the switching devices are caused to alternately turn ON at specific intervals, the vibrating element vibrates at a natural resonant frequency, transmitting thereby an ultrasonic signal.

An actuator includes a solenoid with a ferromagnetic nucleus which slides inside the solenoid. The nucleus is combined with a rod appropriate for interacting with a turbocharger's pivot point. The actuator is provided with a sensing system of the position of the ferromagnetic nucleus in the solenoid. The actuator also includes an electronic circuit which:—on the way in receives at least the signal from the engine's electronic control unit and the feedback signal, connected to the position of the ferromagnetic nucleus of the solenoid;—on the way out it distributes the electric current, connected to the entry signals, with which it feeds the solenoid.

The invention provides a micro-nano thin film magnetosonic antenna comprising a pedestal. The middle portion of the upper surface of the pedestal is provided with a cavity; the bottom and the side wall of the cavity and the upper surface of the pedestal are provided with insulation layers connected to a whole; a supporting layer is arranged on the insulation layer on the upper surface of the pedestal; the middle portion of the supporting layer is arranged over the cavity in a suspended manner; a magnetism-sound-electricity coupled structure consisting of magnetostrictive thin films and a thinfilm bulk acoustic wave resonator is arranged on the supporting layer; the magnetism-sound-electricity coupled structure is located right above the cavity; each magnetostrictive thin film consists ofmultiple magnetostrictive thin film layers and multiple buffer layers, wherein the number of the magnetostrictive thin film layers and the number of the buffer layers are the same and the magnetostrictive thin film layers and the buffer layers are arranged in an alternate manner. While being miniaturized, the antenna has better performance than conventional electric antennas.

A magnetostrictive actuator comprises a rod of giant magnetostrictive material, biasing permanent magnets arranged at each end thereof and coaxially therewith so as to pass a magnetic field through the rod. An energizing electromagnetic coil is connected to an energizer so as to superimpose on the magnetic field passing through the rod an alternating magnetic field to cause variation in the length of the rod in response thereto. The permanent magnets are each in the form of a disc having a cross-sectional area substantially greater than that of the rod and are spaced from the ends of the rods by material of low magnetic permeability. The magnetic field in the rod is thereby substantially linear along the length thereof.

The invention belongs to measuring and controlling technique filed of electromechanic system, relates to realizing method and control system based on self-apperceive performer of double-direction electromechanic transducing material. Time division multiplexing decoupling and control system of self-apperceive performer adopts double-direction transducing element, using switching sequence control circuit to control double-direction transducing element as sensor or performer, when the double-direction transducing element is as the sensor, it used sensing switch, when the double-direction transducing element is as the performer, it used executing switch, it uses discharging switch to discharge the double-direction transducing element, the three switches are conducted or closed under control of switch sequence control circuit. The invention decreases volume and weight of electromechanic system, and makes structure controlled integrated and micromated, decreases difficulty of craftwork and installation; it is controlled in parity, increases stability of control. It fits for structure libration initiative control, system identification and health diagnosis, especially fits for flexible structure whose volume and weight are limited.

The invention comprises: a magnetostriction component, a central pipe eradiator, a driving coil, a closed case, a cooling media channel, a bias magnet, a forced cooling mechanism. A group of magnetostriction materials is laminated to form ring-shaped or sector-shaped driving component; on the lamination there is a sector-shaped or hole-shaped window opened; the central pipe eradiator is connected to the radiating face of the magnetostriction component; the driving coil for generating magnetic field is located on the group of laminations; on the closed case there are an entrance and outlet of cooling media and a connector of magnet field power.

Provided is a system and method for enabling pressure or acoustic waves to induce magnetostrictive volume or shape change, providing greater control over magnetopropants. A coating material and the spacing between a magnetopropant and a magnetic particle are selected such that a certain pressure causes change in the relative distance of magnetopropant and magnetic particle, thereby changing the amount of magnetostriction. The coating material, magnetopropant, and magnetic particle are assembled to form a pressure sensitive magnetopropant. Given this structure, changes in pressure will cause a fluctuation of the amount of magnetostriction. In a pore space environment, this causes a change in pore space with resulting change in permeability and, hence, changes in fluid flow.

A method and apparatus for modulating light of CCFLs that couples frequency alteration and pulse width modulation (PWM) approaches to change output voltage and current of a piezoelectric transformer to modulate the luminosity of a CCFL. The invention includes a PWM controller to alter operation cycle and a frequency control IC to change resonant frequency that drives the piezoelectric transformer at different operation cycles thereby to modulate the luminosity of the CCFL and improve the life span of the piezoelectric transformer.

An actuator device having an expansion unit (10), which comprises a magnetically active shape memory alloy material (12) and which carries out an expansion movement from a starting position along an expansion direction as a reaction to an energization of a coil device (30) and interacts with restoring means which exert on the expansion unit (10) a restoring force opposite to the expansion direction, wherein the restoring force has permanent magnets which act or are seated on a section of the expansion unit (10) such that the restoring force generated magnetically by the permanent magnets changes with increasing expansion stroke in the expansion direction, wherein the permanent magnets (16, 34, 40, 52, 54) are embodied and / or designed such that the expansion unit (10) can contract into the starting position along the expansion stroke when the coil device (30) is not energized.

The operational frequency of existing magnetoelectric materials having metallic or ceramic magnetostrictive materials and ceramic piezoelectric materials may be limited to a few kilohertz due to the presence of eddy-current losses in the metallic magnetostrictive phase. Further, these materials may be difficult to machine and fabricate due to their brittleness. Additionally, it may be difficult to tailor and optimize the properties (i.e., magnetoelectric voltage coefficient αE, etc.) of the devices. This invention provides a magnetoelectric element including at least one set of alternative piezoelectric layer and magnetostrictive composite layer. The magnetostrictive composite layer includes at least one magnetostrictive material dispersed in first concentrated zones within a first polymer matrix, wherein all of said concentrated zones are orientated along a first direction. It is found that the conversion efficiency (i.e., αE) varies in accordance with applied magnetic control field Hcontrol.

The invention provides a cantilever magnetic sensor. The sensor comprises a base and a cantilever beam, wherein one end of the cantilever beam is fixed on the base, and the other end of the cantileverbeam is a free end; a magnet is arranged on the cantilever beam; and the cantilever beam vibrates under the act of a vibrating source in the working state, the frequency and amplitude of vibration are changed due to the magnetic torque generated by the magnet when an external magnetic field acts on the magnet, and the magnetic field can be detected by detecting the frequency and amplitude of thevibration. The magnetic sensor is simple in structure, and can realize high-sensitivity magnetic field detection.

A torsional vibration magneto-electric coupler based on the Wedman effect and a making method thereof are provided. In the torsional vibration magneto-electric coupler based on the Wedman effect, twopermanent magnets are uniformly distributed and bonded to the outer circumferential surface of a magnetostrictive cylinder to form a magnetic fastener. A piezoelectric cylindrical shell composite is formed by splicing 6 to10 piezoelectric strips with an arc cross section, and the number of the piezoelectric strips is even. During splicing, the splicing surface of every two adjacent piezoelectric strips is coated with an electrode layer of which the thickness is less than or equal to 0.5mm. The polarization directions of two adjacent piezoelectric strips are opposite. The polarization directions of two adjacent electrode layers are opposite. An annular DC magnetic field is generated by using the permanent magnets, and the annular DC magnetic field and an additional AC magnetic field form aspiral magnetic field. A stronger magnetoelectronic coupling effect can be obtained, and higher magneto-electric voltage signals can be output. Moreover, potential noise sources can be filtered, and the signal-to-noise ratio in the sensing mode can be further improved. The torsional vibration magneto-electric coupler has the characteristics of simple structure and miniaturization.

A contraction type actuator 10 is provided which can efficiently and evenly apply a bias magnetic field to a magnetostrictive rod to obtain a large contraction amount, while having a small and simple structure.In the contraction type actuator 10, a giant magnetostrictive rod 12 flexibly expands and contracts by controlling the strength of a magnetic field applied by a magnet coil 14. A bias magnet comprises a first bias magnet 16 and a second bias magnet 18. The fist bias magnet 16 in an approximately cylindrical shape is coaxially disposed around the giant magnetostrictive rod 12. The second bias magnet 18 is disposed in the inner space 16A of the first bias magnet 16, and is polarized in the direction of drawing a part of a magnetic field generated by the first bias magnet 16 into the inner space 16A.

The present invention provides a resonator capable of varying its resonance frequency of good performance with a low dispersion at a high manufacturing yield and a low cost. The resonator comprises a fixed electrode 1; a movable electrode 3 arranged with a predetermined distance apart from and parallel to the fixed electrode; a plurality of conductive leaf springs 2 with conductive property, all of which are bent outward or inward beforehand, arranged parallel apart from each other wherein, one end of each leaf spring is integrated into the fixed electrode and the other end of each leaf spring is integrated into the movable electrode; and an actuator 6 attached to the movable electrode for deforming the leaf springs by pushing or pulling the movable electrode.

A method of producing a piezoelectric / electrostrictive device having a base including a pair of movable parts opposing each other, a fixing part that connects the movable parts with each other at one end thereof, and mounting parts that extend for a predetermined length while holding slit-shaped gaps of a predetermined width along inside surfaces of said movable parts by being turned around at the other end of said movable parts, said piezoelectric / electrostrictive device having a piezoelectric / electrostrictive element disposed on at least one outside surface of said movable parts of said base, wherein a base block obtained by laminating and calcining a large number of ceramic green sheets is adopted as a material for forming said base, and the base including said movable parts, said fixing part, and said mounting parts is formed by cutting said base block at a predetermined site along a lamination direction of said ceramic green sheets.

Systems and methods for flaw detection and monitoring at elevated temperatures with wireless communication using surface embedded, monolithically integrated, thin-film, magnetically actuated sensors, and methods for fabricating the sensors. The sensor is a monolithically integrated, multi-layered (nano-composite), thin-film sensor structure that incorporates a thin-film, multi-layer magnetostrictive element, a thin-film electrically insulating or dielectric layer, and a thin-film activating layer such as a planar coil. The method for manufacturing the multi-layered, thin-film sensor structure as described above, utilizes a variety of factors that allow for optimization of sensor characteristics for application to specific structures and in specific environments. The system and method integrating the multi-layered, thin-film sensor structure as described above, further utilizes wireless connectivity to the sensor to allow the sensor to be mounted on moving components within the monitored assembly.