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.

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.

A holder located on a casing using for loading a hard disk includes a bottom surface, at least a first elastic element and at least a second elastic element. The bottom surface is facing to a first surface of the casing. The first elastic element is located on the bottom surface having a first end connected to the bottom. At least a part of the first elastic element is configured through an opening and clipped on a second surface of the case. There is at least an opening configured through the first surface and the second surface. The second surface is in opposition to the first surface. A third end of the second elastic element is connected to the bottom surface, and at least a part of the second elastic element contacts against the first surface.

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.

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.

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.

A magnetic actuator is provided including a magnetic field-actuated material and a plurality of interconnected electrically conducting coils, each coil including a number of wire turns arranged relative to at least one other coil to produce at the magnetic field-actuated material, by superposition, a magnetic field that is substantially oriented in one of a plurality of selectable discrete directions. An actuator drive circuit is connected to the coils in a circuit configuration that reverses a direction of electrical current flow through at least one of the coils to reorient the magnetic field from a first selected direction to a second selected direction of the plurality of selectable discrete directions.

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.

A phase change memory comprises a phase-change recording layer for recording information through changing between a crystal phase and an amorphous phase; and a means for applying a tensile strain onto the phase-change recording layer, thereby providing the memory having high reliability, as well as, high tolerance or durability against repetitive rewriting operation.

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 holder located on a casing using for loading a hard disk includes a bottom surface, at least a first elastic element and at least a second elastic element. The bottom surface is facing to a first surface of the casing. The first elastic element is located on the bottom surface having a first end connected to the bottom. At least a part of the first elastic element is configured through an opening and clipped on a second surface of the case. There is at least an opening configured through the first surface and the second surface. The second surface is in opposition to the first surface. A third end of the second elastic element is connected to the bottom surface, and at least a part of the second elastic element contacts against the first surface.

A power generating element having arranged side-by-side therein a magnetostrictive rod comprising a magnetostrictive material and causing a line of magnetic force to pass through in the axial direction and a reinforcing rod comprising a non-magnetic material and having a function that applies an appropriate stress to the magnetostrictive rod; having a composite rod comprising mutually bonded bonding sections and a coil arranged such that the line of magnetic force passes through in the axial direction and generating voltage on the basis of changes in the density thereof; and configured so as to cause the density of the line of magnetic force to change, by relatively displacing one end of the composite rod relative to the other end, in a direction substantially vertical relative to the axial direction thereof, and causing the magnetostrictive rod to expand and contract.

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.

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.