Showing papers on "Transducer published in 2011"

Surgical instrument with ratcheting rotatable shaft

Abstract: An ultrasonic surgical instrument comprises a reusable housing including an internal transducer and an internal end effector rotation assembly. An exemplary rotation assembly is a ratchet and pawl assembly, which allows the transducer to rotate in a first direction but not in a second, opposite direction. The end effector, including an integral torque wrench, is attached to the transducer to form a single unit that is rotatable relative to the housing. The transducer attaches to a stationary cable via slip rings. The cable communicates with a generator, which provides electrical power to the transducer. The transducer converts the electrical power into ultrasonic vibrational energy, which is transmitted to the end effector.

Surgical instrument with slip ring assembly to power ultrasonic transducer

Abstract: A surgical instrument includes a rotatable electrical coupling assembly having a first part and a second part that electrically couple and rotate relative to each other. The second part is carried by and rotates with a tube collar coupled to a transducer. A portion of the transducer is inserted through an aperture of the second part, but does not contact the second part. The first part of the assembly may electrically couple to the second part via pogo pins, brush contacts, or ball bearings. Alternatively, the first part may comprise conductive channels formed in the casing. The second part may comprise a rotatable drum with a conductive trace. In some versions, one or more components may comprise MID components. In another version, the rotatable electrical coupling assembly comprises a rotatable PC board and brush contact. Further still, a circuit board may be provided with the transducer inside a transducer casing.

Surgical instrument with clutching slip ring assembly to power ultrasonic transducer

Abstract: A surgical system includes a power supply, a connector, and a surgical instrument having a body assembly, a transmission assembly, a transducer, and a connection assembly. The connection assembly is configured to selectively electrically couple electrodes on the transducer with wires of the connector. The connection assembly may be operable in response to actuation of a trigger. Various connection assemblies include an extensible member that extends to contact an electrode, a rotatable member that rotates a contact into contact with an electrode, a solenoid that extends contacts coupled to each end of the solenoid into the electrodes, or a solenoid that translates a frame having contacts towards the electrodes. Alternatively, the surgical instrument may include a connection assembly having a slip ring and a weighted cable end. Still further, the connection assembly may include contacts on a coupleable member that may be decoupled from contacts on the transducer.

Cam driven coupling between ultrasonic transducer and waveguide in surgical instrument

Abstract: A surgical instrument includes a body assembly, a waveguide, a transducer, and a coupling assembly. In some versions the coupling assembly translates the transducer to couple the transducer to the waveguide. For instance, a gear having arcuate troughs may engage pins on the transducer and/or waveguide to mate the transducer to waveguide. A pawl may selectively engage and prevent rotation of the gear. Alternatively, lever arms may cam the transducer into the waveguide. The lever arms may selectively couple to a casing to prevent decoupling of the transducer and waveguide. In another configuration, a locking tab can be slid and locked into a slot to couple the transducer and waveguide. Further still, levers with self-locking pins may engage and couple the transducer to the waveguide. In another version, a rotatable body portion may engage a tab on the transducer to rotate and couple the transducer to the waveguide.

Passively powering a wireless communications device

Abstract: A wireless device includes an RF interface, logic circuitry, power circuitry, an impedance matching transformer, and a transducer. The RF interface is configured to receive an RF signal and provide an output data signal derived from the RF signal. The logic circuitry is configured to receive the output data signal and provide an output analog signal. The power circuitry is coupled to the RF interface and configured to provide DC operating power derived from the RF signal to the RF interface and the logic circuitry. The impedance matching transformer has an input coupled to the logic circuitry and an output. The transducer is coupled to the output of the impedance matching transformer and is configured to produce an audio signal based on the output analog signal.

Energy Scavenging Power Supply

Abstract: An energy scavenging power system and method may include an energy conversion system having at least one transducer configured to harvest energy, an energy management and storage system configured to store harvested energy; and a load regulation system configured to provide stored energy to power one or more low power-consumption loads The energy management and storage system may include a start-up capacitor having a small capacitance to allow for quick charging and fast turn-on, a short term capacitor to provide energy to the load or loads once turned-on, and a long term capacitor having a large capacitance to provide for sustained energy delivery to the loads The system also may include a common charging bus that receives energy from each transducer, conditioned if necessary, and which then determines the capacitor to which the energy should be delivered

Energy harvesting device including mems composite transducer

Abstract: An energy harvesting device includes a MEMS composite transducer. The MEMS composite transducer includes a substrate. Portions of the substrate define an outer boundary of a cavity. A MEMS transducing member includes a beam having a first end and a second end. The first end is anchored to the substrate and the second end cantilevers over the cavity. A compliant membrane is positioned in contact with the MEMS transducing member. A first portion of the compliant membrane covers the MEMS transducing member. A second portion of the compliant membrane is anchored to the substrate. The compliant member is configured to be set into oscillation by excitations produced externally relative to the energy harvesting device.

An Imaging Model Incorporating Ultrasonic Transducer Properties for Three-Dimensional Optoacoustic Tomography

Abstract: Optoacoustic tomography (OAT) is a hybrid imaging modality that combines the advantages of optical and ultrasound imaging. Most existing reconstruction algorithms for OAT assume that the ultrasound transducers employed to record the measurement data are point-like. When transducers with large detecting areas and/or compact measurement geometries are utilized, this assumption can result in conspicuous image blurring and distortions in the reconstructed images. In this work, a new OAT imaging model that incorporates the spatial and temporal responses of an ultrasound transducer is introduced. A discrete form of the imaging model is implemented and its numerical properties are investigated. We demonstrate that use of the imaging model in an iterative reconstruction method can improve the spatial resolution of the optoacoustic images as compared to those reconstructed assuming point-like ultrasound transducers.

Transducer and transducer module

Abstract: Transducers and transducer modules having the transducers are disclosed. An embodiment discloses a transducer (10) that comprises a conductive layer (30E) having a U-shaped slit (100) toward its swing end (A). The slit is configured to enhance a haptic feedback or an acoustic propagation, or adjust a resonant mode.

Method and system for providing an energy assisted magnetic recording disk drive having a non-conformal heat spreader

Abstract: An energy assisted magnetic recording (EAMR) transducer coupled with a laser is described. The EAMR transducer has an air-bearing surface (ABS) residing near a media during use. The laser provides energy. The transducer includes a waveguide, a near field transducer (NFT) proximate to the ABS, a write pole, a heat spreader, and at least one coil. The waveguide directs the energy from the laser toward the ABS. The NFT is optically coupled with the waveguide, focuses the energy onto the media, and includes a disk having an NFT width. The write pole writes to the media. The heat spreader is thermally coupled with the NFT. A first portion of the heat spreader is between the NFT and the pole, is between the ABS and a second portion of the heat spreader, and has a first width. The second portion has a second width greater than the first width.

In-Air Rangefinding With an AlN Piezoelectric Micromachined Ultrasound Transducer

Abstract: An ultrasonic rangefinder has a working range of 30 to 450 mm and operates at a 375-Hz maximum sampling rate. The random noise increases with distance and equals 1.3 mm at the maximum range. The range measurement principle is based on pulse-echo time-of-flight measurement using a single transducer for transmit and receive. The transducer consists of a piezoelectric AlN membrane with 400-μm diameter, which was fabricated using a low-temperature process compatible with processed CMOS wafers. The performance of the system exceeds the performance of other micromechanical rangefinders.

Method and system for providing a read transducer having a reduced shield-to-shield spacing

Abstract: A method and system for providing a read magnetic transducer having an air-bearing surface (ABS) is described. The magnetic read transducer includes a first shield, a read sensor stack, an antiferromagnetic (AFM) tab, and a second shield. The read sensor stack includes a pinned layer, a spacer layer, and a free layer. The spacer layer is nonmagnetic and between the pinned layer and the free layer. A portion of the read sensor stack is at the ABS. The AFM tab is recessed from the ABS and adjacent to a portion of the pinned layer. The read sensor resides between the first shield and the second shield.

Method and system for providing a side shielded read transducer

Abstract: A method and system for providing a magnetic transducer having an air-bearing surface (ABS) is described. The magnetic read transducer includes a first shield, a magnetoresistive sensor, at least one soft magnetic side shield, and a second shield. The magnetoresistive sensor includes a sensor layer having at least one edge in the track width direction along the ABS. The at least one soft magnetic side shield is adjacent to the at least one edge of the sensor layer. The at least one soft magnetic side shield has a full film permeability of at least ten. The magnetoresistive sensor is between the first shield and the second shield and free of an in-stack hard bias layer.

Systems and methods for providing a pole pedestal for microwave assisted magnetic recording

Abstract: Systems and methods for providing a write pole pedestal for microwave assisted magnetic recording systems are provided. One such system includes a magnetic transducer for microwave assisted magnetic recording, the magnetic transducer including a pole including a leading edge and a trailing edge, a trailing shield positioned closer to the pole trailing edge than the pole leading edge, and an energy transducer positioned between the pole trailing edge and the trailing shield, where a trailing parallel side of the trapezoid is smaller than a leading parallel side of the trapezoid.

Energy-assisted magnetic recording head having multiple cores of different lengths

Abstract: A method and system for providing a waveguide for an energy assisted magnetic recording (EAMR) transducer is described. The EAMR transducer has an air-bearing surface (ABS) that resides in proximity to a media during use and is coupled with a laser that provides energy. The EAMR transducer includes a write pole that writes to a region of the media and coil(s) that energize the write pole. The waveguide includes first and second cladding layers, a core, and assistant cores. The core is configured to direct the energy from the laser toward the ABS and has a core length. The core resides between the first and second cladding layers. A first portion of the assistant cores resides in the first cladding layer. A second portion of the assistant cores is in the second cladding layer. Each assistant core has an assistant core length less than the core length.

Dual-function transducer for a touch panel

Abstract: A dual-function transducer for a force-sensitive multi-touch screen, including a first substrate, at least one electrode array formed on the first substrate, the at least one electrode array including first and second electrodes, and circuitry operatively coupled to the first and second electrodes. The circuitry is configured to measure first and second electrical properties of the electrode array, the first and second electrical properties corresponding to touch and strain, respectively.

Method and system for providing a magnetic read transducer having an improved signal to noise ratio

Abstract: A method and system for providing a magnetic read transducer is described. The magnetic read transducer includes a magnetoresistive sensor a shield, and a spin pumping barrier layer. The magnetoresistive sensor includes a pinned layer, a spacer layer, and a free layer. The spacer layer is nonmagnetic and resides between the pinned layer and the free layer. The free layer is between the pinned layer and the shield. The spin pumping barrier layer is between the shield and the free layer.

Method and system for providing a read transducer having an adaptive read sensor track width

Abstract: A method and system provide a magnetic read transducer having an air-bearing surface (ABS). The magnetic transducer includes a first shield, a second shield, and a read sensor between the first shield and the second shield. The read sensor extends along a stripe height direction perpendicular to the ABS. A first portion of the read sensor at the ABS has a first width in a track width direction parallel to the ABS. A second portion of the read sensor is recessed from the ABS along the stripe height direction and has a second width in the track width direction. The second width is greater than the first width.

Systems and methods for providing stacked writer leads for magnetic transducers

Abstract: Systems and methods for providing stacked writer leads for magnetic transducers used in disk drives are provided. One such system for providing stacked writer leads for a magnetic transducer includes a writer coil for the magnetic transducer, a first pad on the magnetic transducer, a second pad on the magnetic transducer, a first circuit trace coupled to the first pad and a first terminal of the writer coil, and a second circuit trace coupled to the second pad and a second terminal of the writer coil, where a preselected length of the first circuit trace and the second circuit trace is configured in a stacked configuration where each of the preselected lengths of the first circuit trace and the second circuit trace is positioned at about the same location in spaced apart planes.

Method for fabricating a read sensor for a read transducer

Abstract: A read sensor for a transducer is fabricated. The transducer has a field region and a sensor region corresponding to the sensor. A sensor stack is deposited. A hybrid mask including hard and field masks is provided. The hard mask includes a sensor portion covering the sensor region and a field portion covering the field region. The field mask covers the field portion of the hard mask. The field mask exposes the sensor portion of the hard mask and part of the sensor stack between the sensor and field regions. The sensor is defined from the sensor stack in a track width direction. Hard bias layer(s) are deposited. Part of the hard bias layer(s) resides on the field mask. Part of the hard bias layer(s) adjoining the sensor region is sealed. The field mask is lifted off. The transducer is planarized.

High-temperature (>500°c) wall thickness monitoring using dry-coupled ultrasonic waveguide transducers

Abstract: Conventional ultrasonic transducers cannot withstand high temperatures for two main reasons: the piezoelectric elements within them depolarize, and differential thermal expansion of the different materials within a transducer causes them to fail. In this paper, the design of a high-temperature ultrasonic thickness gauge that bypasses these problems is described. The system uses a waveguide to isolate the vulnerable transducer and piezoelectric elements from the high-temperature measurement zone. Use of thin and long waveguides of rectangular cross section allows large temperature gradients to be sustained over short distances without the need for additional cooling equipment. The main problems that had to be addressed were the transmission and reception of ultrasonic waves into and from the testpiece that the waveguides are coupled to, and optimization of the wave propagation along the waveguide itself. It was found that anti-plane shear loading performs best at transmitting and receiving from the surface of a component that is to be inspected. Therefore, a nondispersive guided wave mode in large-aspect-ratio rectangular strips was employed to transmit the anti-plane shear loading from the transducer to the measurement zone. Different joining methods to attach the waveguides to the component were investigated and experiments showed that clamping the waveguides to the component surface gave the best results. The thickness of different plate samples was consistently measured to within less than 0.1 mm. Performance at high temperatures was tested in a furnace at 730°C for 4 weeks without signal degradation. Thicknesses in the range of 3 to 25 mm could be monitored using Hanning windowed tonebursts with 2 MHz center frequency.

Method and system for providing a read sensor in a magnetic recording transducer using focused ion beam scan polishing

Abstract: A read sensor for a read transducer is fabricated. The read transducer has field and device regions. A read sensor stack is deposited. A mask covering part of the stack corresponding to the read sensor is provided. The read sensor having inboard and outboard junction angles is defined from the stack in a track width direction. A critical junction (CJ) focused ion beam scan (FIBS) polishing that removes part of the read sensor based on the junction angles is performed. A hard bias structure is deposited and the transducer planarized. A remaining portion of the mask is removed. A stripe height mask covering part of the read sensor and hard bias structure in a stripe height direction is provided. The read sensor stripe height is defined. A tunneling magnetoresistance (TMR) FIBS polishing that removes part of the stack in the field region is performed. An insulating layer is provided.

Magnetic recording head with dynamic fly height heating and having thermally controlled pole tip protrusion to control and protect reader element

Abstract: A magnetic recording device includes a slider having an air bearing surface (ABS), a leading side, and a trailing side and a head residing on the slider. The head has a first magnetic transducer and a first heater for heating an area proximal to the first magnetic transducer. A first shield (S1) comprising a first material is on the leading side of the first magnetic transducer and a second shield (S2) comprising the first material is on the trailing side of the first magnetic transducer. A first pole (P1) comprising the first material is on the trailing side of the second shield (S2), and the first pole (P1) is between 0.6 micron and 2.0 micron thick; and the second shield (S2) is less than 0.6 micron thick. A hard disk drive includes the magnetic recording device.

Method and system for providing a read transducer having soft and hard magnetic bias structures

Abstract: A method and system provide a magnetic transducer having an air-bearing surface (ABS). The magnetic transducer includes a first shield, a read sensor, at least one soft magnetic bias structure and at least one hard bias structure. The read sensor includes a sensor layer that has at least one edge in the track width direction along the ABS. The soft magnetic bias structure(s) are adjacent to the edge(s) of the sensor layer. The soft magnetic bias structure has a first permeability. The soft bias structure(s) are between the read sensor and the hard bias structure(s). The hard bias structure(s) are adjacent to a portion of the soft bias structure(s) and have a second permeability. The first permeability is at least ten multiplied by the second permeability.

Energy harvesting from mechanical vibrations using multiple magnetostrictive/piezoelectric composite transducers

Abstract: This paper describes an energy harvester employing multiple Terfenol-D/Pb(Mg 1/3 Nb 2/3 )O 3 –PbTiO 3 /Terfenol-D laminate magnetoelectric transducers to convert ambient mechanical vibration into electrical energy. The harvester uses four magnets arranged on the free end of a cantilever beam. The multiple transducers are placed in the air gap between the magnets. The optimal initial positions of the transducers at the static equilibrium are analyzed. And the output characteristics of the harvester employing various numbers of transducers are experimentally studied. Experimental results indicate that the harvester employing multiple transducers can provide higher power and power density. The harvester employing four transducers produces a maximum output power of 7.13 mW, which is 3.95 times higher than that of the harvester employing a single transducer, and the harvester employing two transducers produces a maximum output power of 4.07 mW, which is 1.83 times higher than that of the harvester employing a single transducer.

Design and experimental characterization of an electromagnetic transducer for large-scale vibratory energy harvesting applications

Abstract: This article reports on the design and experimental characterization of an electromagnetic transducer for energy harvesting from large structures (e.g., multistory buildings and bridges), for which the power levels can be above 100 W and disturbance frequencies below 1 Hz. The transducer consists of a back-driven ballscrew coupled to a permanent-magnet synchronous machine with power harvesting regulated via control of a four-quadrant power electronic drive. Design considerations between various subsystems are illustrated and recommendations in terms of minimal values are made for each design metric. Developing control algorithms to take full advantage of the unique features of this type of transducer requires a mechanical model that can adequately characterize the device’s intrinsic nonlinear behavior. A new model is proposed that can effectively capture this behavior. Comparison with experimental results verifies that the model is accurate over a wide range of operating conditions. As such, the model can...

Recording head for heat assisted magnetic recording with diffusion barrier surrounding a near field transducer

Abstract: An apparatus includes a near field transducer positioned adjacent to an air bearing surface, a first magnetic pole, a heat sink positioned between the first magnetic pole and the near field transducer, and a diffusion barrier positioned between the near field transducer and the first magnetic pole. The diffusion barrier can be positioned adjacent to the magnetic pole or the near field transducer.

Bias observed in time-of-flight shear wave speed measurements using radiation force of a focused ultrasound beam.

Abstract: Measurement of shear wave propagation speed has important clinical applications because it is related to tissue stiffness and health state. Shear waves can be generated in tissues by the radiation force of a focused ultrasound beam (push beam). Shear wave speed can be measured by tracking its propagation laterally from the push beam focus using the time-of-flight principle. This study shows that shear wave speed measurements with such methods can be transducer, depth and lateral tracking range dependent. Three homogeneous phantoms with different stiffness were studied using curvilinear and linear array transducer. Shear wave speed measurements were made at different depths, using different aperture sizes for push and at different lateral distance ranges from the push beam. The curvilinear transducer shows a relatively large measurement bias that is depth dependent. The possible causes of the bias and options for correction are discussed. These bias errors must be taken into account to provide accurate and precise time-of-flight shear wave speed measurements for clinical use.