Abstract: The invention concerns a reactor with acoustic cavitation comprising a tube (10) made of flexible material, wherein the liquid to be treated circulates. Electro-acoustic transducers (1) are radially and uniformly distributed around the tube (10). Each electro-acoustic transducer (1) has a general prismatic shape with a base of specific width and a head narrower than the base, the head pressed on the tube (10). Each electro-acoustic transducer (1) includes an electro-acoustic motor (78) mounted at the base such that the vibrations generated by the electro-acoustic motor (78) are amplified at the head by the electro-acoustic transducer (1) shape. Lubricating films (9) extend between the electro-acoustic transducers (1) heads and the tube (10), so as to produce an acoustic coupling of the electro-acoustic transducers with the tube. The whole set is in a sealed chamber (83) where the pressure is maintained at a predetermined value and where the lubricating and cooling liquid circulates.

Abstract: An electromagnetic vibratory microplate shaker is disclosed of simplified design and improved mixing capability over previously known microplate shaker devices, comprising an electromagnetic drive assembly mounted within a rigid base and operatively connected to a microplate support tray. The support tray is in turn supported from below by a plurality of leaf springs which are tilted approximately 20° from vertical. During operation, an electromagnet is rapidly energized and de-energized causing an armature of the drive assembly to be pulled in and released up to 7,200 times per minute, in turn imparting a reciprocating vibration to the support platform and the microplates held thereon.

Abstract: The inventive apparatus is comprised of a means for producing cavitation in a complex reaction mixture to enhance the yield of the selected reaction product, a means for controlling the temperature of the complex reaction mixture, especially during cavitation, and a means for affecting magnetic separation of paramagnetic beads to which the selected reaction product is attached from the complex reaction mixture. In one embodiment, the compound(s) or molecule(s) is synthesized in situ, and isolated using the inventive apparatus. The apparatus finds use in the fields of solid phase organic synthesis, and for isolation and purification of a selected compound(s) or molecule (s), especially where automation is desired.

Abstract: A stirrer for mixing a sample solution. In order to make a structure wherein drops are not liable to remain in a channel without an increase in flow resistance in a microtube, ultrasonic vibrators are arranged in the stirring tube and plural sample solutions to be mixed are stirred and mixed by an acoustic streaming from ultrasounds generated by the vibrators.

Abstract: A stirring device has an actuator like a plate, a cover shaped like a rectangular box and covering the actuator, a blade designed to be vibrated by the actuator, and a connecting device connecting the blade to the actuator, positioning an axis of vibration amplitude of the blade substantially in one side of the cover.

Abstract: A burner system is provided which creates standing waves in the gas/air flow within the burner so as to vary the pressure distribution along the length of the burner and thus the heights of the flames produced along the length of the burner. By changing the standing waves, the pressure distributions within the burner are changed, thereby causing the burner to produce changing flame patterns that simulate realistic wood burning flame patterns. In another embodiment, two orthogonal or sinusoidal gas/air flows offset by a phase angle are generated within the burner creating a beat frequency. By varying the phase angle offset, the rate of occurrence of the beats defining the beat frequency are varied resulting in the variation of the pressure distribution within the burner. Consequently, the flame patterns generated by the burner are varied simulating the appearance of realistic wood burning flame patterns.

Abstract: A chemical mechanical polishing apparatus comprises a delivery system for supplying a slurry, wherein the slurry includes suspended particles and at least one acoustic element, connected to the delivery system, the acoustic element generating sound waves for agitating the slurry and maintaining the particles in suspension.

Abstract: A melt-extrudable polymeric strand with enhanced tensile strength formed by extruding a melt-extrudable polymer while subjecting the a portion of the polymer to ultrasonic energy. The melt-extrudable polymeric strand has a tenacity which is from about 1.5 to about 3 times the tenacity of an otherwise identical strand not made by applying ultrasonic energy to a portion of the melt-extrudable polymer while the melt-extrudable polymer is extruded. Desirably, the strand has a tenacity within a range from about 0.3 to about 0.9 g/denier. In a method for making such a strand, a molten melt-extrudable polymer is extruded through a die assembly, ultrasonic energy is applied to a portion of the melt-extrudable polymer within the chamber and without applying ultrasonic energy to the die tip, while an extrusion exit orifice receives melt-extrudable polymer from an extrusion chamber, and the extruded polymer is attenuated to form a strand.

Abstract: A metallic flake manufacturing device uses a bearing to form the flakes. The bearing is located within a container which receives a fluid having suspended metallic particles. The bearing has an outer race, an inner race, and a plurality of bearings disposed between the races. The bearings are immersed in the fluid for flattening the suspended particles into flakes. A shaft extends into the container. The shaft engages one of the races for rotating it relative to the other race.

Abstract: In a combination type humidifier having a heater and an ultrasonic vibrator, an art for preventing the ultrasonic vibrator from being thermally damaged due to a heat produced by the heater is disclosed. First, a current humidity of a space, a water temperature of a humidifying chamber and a target humidity set by a user are detected. When the current humidity is higher than the target humidity, a fan motor begins to operate for a rapid heat loss. Otherwise, when the target humidity is higher than the current humidity, an error message concerning the setting of the target humidity is displayed and the fan motor is driven for a predetermined time. The heater is controlled so that the water temperature of the humidifying chamber is kept below the limit temperature by using a result of comparing the water temperature of the humidifying chamber with a limit temperature that is set for protecting the ultrasonic vibrator while the ultrasonic vibrator and the heater are simultaneously operated by a user's selection.

Abstract: A chamber for exerting an ultrasound beam on a sample solution containing particles to be concentrated, separated or arranged is provided with a view toward arbitrarily controlling the shape of a spatial distribution of potential energy created by the ultrasound beam and concentrating, separating or periodically arranging the particles. In contrast to the chamber, irradiation ultrasound sources for generating ultrasound beams are provided to create an ultrasonic intensity distribution for producing a position potential energy distribution used to exert a force forwarded in a predetermined direction or a force staying at a predetermined region to each particle. Thus, a specific spatial distribution of potential energy can be realized by ultrasound beams each having a specific intensity, a specific frequency and a specific phase or an ultrasound beam formed by superimposing these on one another.

Abstract: A device and method for mixing an aspirated fluid slug (40), such as a DNA sample and reagent, within a capillary tube (28) through the electrical deflection of a diaphragm, such as a piezo-ceramic disk (12). The device (10) includes first and second mounting plates (16, 18). The piezo-ceramic disk (12) is sandwiched between two O-rings seals (14) and the two mounting plates (16, 18) to form an air seal (21) between the disk (12) and the first mounting plate (16). A first opening (24) receives an end (26) of the capillary tube (28) and extends almost completely through the first mounting plate (16) such that the end (26) is essentially perpendicular and adjacent to the disk (12). A smaller axially-aligned second opening (30) connects the air seal (21) between the disk (12) and the first mounting plate (16) to dead air volume (42) in the capillary tube (28). A third O-ring seal (34) seals the capillary tube (28) to the first mounting plate (16) at the first opening (24).

Abstract: A process for compatibly hydrating a fragmented solid which forms a gel with an aqueous composition, said process comprising:a. generating a first aqueous composition and a second oily composition containing the said fragmented solid;b. combining the first and second compositions in an at least the essential absence of air; andc. contacting the combined composition with a means for vibratorily mixing the combined composition, thereby causing the combined composition to be sufficiently mixed so as to hydrate the said fragmented solid to the extent that it is compatibilized into the composition and provides a stable gelled aqueous composition.

Abstract: A washing and cleaning device comprises a liquid-tight housing inside which an electrically driven means for producing vibrations transferable from said housing to its invironment is arranged. To achieve a device having a simple structure and working effectively and reliably there is provided an electric motor (10) rigidly secured to the inner wall of said housing (2), said electric motor having an output shaft (12) comprising an imbalanced mass (14) outside the axis of rotation to produce vibrations. An accumulator (16) or a power supply unit (24) is provided as a power source for said electric motor (10).

Abstract: An method and apparatus is described for mixing solid particulates in a molten metal matrix to form a metal matrix composite product flow. The apparatus a refractory vessel to hold the metal matrix; a refractory conduit in communication with both the inlet and outlet of the refractory vessel so as to define a closed loop flow path. The inlet and outlet is spaced so as to encourage mixing within the vessel. A pump is provided to circulate the metal matrix to effect mixing. The apparatus and method further includes the metal matrix having a head with a vertical dimension in the excess of four times the cross sectional width of the conduit.

Abstract: A method of mixing two or more kinds of adhesive resin liquids takes the steps of arranging such that resin outlet ports (6a, 7a) of feed tubes (6, 7) for feeding two or more kinds of resin material liquids which are hardened by reaction face a side skin surface (3b) of an ultrasonic wave transmission solid horn (3), allowing the resin material liquids to flow down passing along the side skin surface (3b) while applying ultrasonic vibrations to the resin material liquids, and guiding the resin material liquids to a distal end face (3a) of the ultrasonic wave transmission solid horn (3), thereby mixing the resin material liquids in an aerial state.

Abstract: A chemical analyzer has turn tables respectively carrying reaction vessels, sample containers and reagent containers disposed thereon in circular rows. A sample pipetting mechanism and a reagent pipetting mechanism are provided to transfer predetermined amounts of sample and reagent solution from a sample container and from a reagent container into a reaction vessel. The thus transferred sample and reagent solution are mixed in the reaction vessel by a stirrer comprising a piezoelectric element which is disposed in non-contacting relationship to the sample and reagent solution in the reaction vessel and is electrically energized to generate a sound wave which causes a circulating flow of the reagent solution in the reaction vessel whereby the sample and the reagent solution are mixed in a non-invasive manner.

Abstract: A rigid ultrasonic radiating plate system assembly designed for fastening to bottom/planes of an ultrasonic cleaning tank. As an initial sub-assembly, the plate has selected threaded bolts/studs which are fitted/welded in a pattern perpendicular to the bottom of the plate. This plate sub-assembly component is fitted through the selected tank plane (bottom/wall), by simultaneously matching the entire bolt/stud hole pattern through to the outside of the tank and on the inside of the tank against the surface of the bottom/wall.

Abstract: A method and apparatus for cleaning articles such as radiators, pizza pans, carburetors, engine parts. A suitable cleaning fluid is placed in a container, and the article to be cleaned is placed in this cleaning fluid. A vibrator is attached to the container such that the vibrations are transferred to the cleaning fluid to clean the articles. The induced waves in the cleaning fluid is a powerful scrubbing force.

Abstract: A device for cleaning dirty objects, for example dirty textiles or dishes, is characterized by a fluid-proof housing (8) immersible in water together with the dirty objects and made to vibrate by means of a drive mechanisms (12; 46). The vibrations may be generated by means of an unbalance weight (26) driven by an electromotor (12), the electromotor (12) and the unbalance weight (26) being arranged inside said housing (8). A charging device for the device (2) comprises a housing (98), with a column-shaped extension being formed on the housing, the outer section of which matches essentially without a gap with the inner section of a receiving chamber of the housing (8) of the device, and an inductive transmitter coil being furthermore arranged inside said extension.

Abstract: Apparatus and methods for filtering particulate matter from a fluid traveg proximate a surface containing a port. First and second ultrasonic wave generators produce superposed ultrasonic waves to define a composite wave pattern in a region of the fluid body upstream of the port. Nodes and antinodes in the composite wave region define regions at which the particulate matter accumulates. The accumulating particulate matter is displaced out of the fluid that enters the port.

Abstract: A method and apparatus for filtering particulate matter entrained in a fl entering a port from a reservoir. First and second ultrasonic wave generators produce ultrasonic waves to define a composite wave pattern. The patterns produce nodes and antinodes in a region through which fluid entering a port passes. The particulate matter in the portion of the fluid passing through the region accumulates along the nodes and antinodes. The accumulating particulate matter is thereby separated and is displaced from the fluid entering the port.

Abstract: An integrated microfabricated instrument for manipulation, reaction and detection of microliter to picoliter samples. The instrument is suited for biochemical reactions, particularly DNA-based reactions such as the polymerase chain reaction, that require thermal cycling since the inherently small size of the instrument facilitates rapid cycle times. The integrated nature of the instrument provides accurate, contamination-free processing. The instrument may include reagent reservoirs, agitators and mixers, heaters, pumps, and optical or electromechanical sensors. Ultrasonic Lamb-wave devices may be used as sensors, pumps and agitators.

Abstract: A device for imparting sonic energy to a continuous flow of an emulsified liquid to de-emulsify the liquid and thereby provide for separation and extraction of selected liquid components. The device utilizes a flat plate oriented in the direction of flow within the liquid so as to impart pressure fronts into the liquid to produce the separation.

Abstract: In a process for sterilization and homogenization of a liquid or fluid, these operations are carried out by subjecting the liquid or fluid to ultrasonic frequency vibrations for a predetermined period of time. In a device for carrying out the process, the liquid taken in from a tank (10) is sent by a pump (11) to a chamber (1), inside of which or in proximity to which is arranged a sonotrode (5) connected to a converter-generator (14). As it travels through this chamber (1), the liquid is subjected to vibrations and is sterilized or homogenized.

Abstract: A system for ultrasonic energy coupling includes an ultrasonic transducer, a horn member defining a passageway, and a pump for moving fluid through the passageway and outwardly of the horn. The method used to accomplish the energy coupling or transfer includes vibrating the horn member with an ultrasonic transducer and pumping fluid through the passageway in the horn member and onto an object.

Abstract: By providing an ultrasonic irradiation apparatus for generating acoustic cavitation efficiently, it is intended to realize an ultrasonic therapeutic apparatus for generating the action of cavitation on a living body suitable for medical treatment of malignant tumors and medical treatment of thrombi and calculi, an ultrasonic diagnostic apparatus for generating cavitation for emphasizing an ultrasonic echo image such as a blood flow and utilizing the reflection capability of the cavitation, an ultrasonic chemical reaction accelerating apparatus, an ultrasonic cleaning apparatus or an ultrasonic sterilizing apparatus. Irradiation focus/code signals for defining irradiated acoustic fields of a fundamental wave and a second harmonic wave as well as focus positions/acoustic pressure distribution forms of the respective waves are applied from an irradiation unit main control circuit to drive phase generating circuits.

Abstract: A low frequency vibration type washing machine is disclosed that is capable of detecting the range of linear reciprocating movement of its drive shaft to control the vibration range of its low frequency oscillating vibrator to be constant, and sensing water level in its washing tub to control the water level. The washing machine includes a low frequency oscillating vibrator adapted to vibrate in a washing tub while being subjected to a water level pressure. The vibrator thereby generates a resonance phenomenon in a multi-phase medium contained in the washing tub.

Abstract: Piezoelectric elements are attached to both sides of a flexible metal thin plate, thus forming a bimorph-type piezoelectric vibrator. A portion of the metal thin plate is extended to form a stirring blade. A suitable weight is attached to a part of the metal plate such that the amplitude of the blade is made greater than the amplitude of the vibrator itself. The voltage to be applied to the vibrator and the frequency are adjusted, and the vibrator is vibrated in a second-order mode. Thereby, the entire solution is moved simultaneously, vertical motion is caused, and the stirring efficiency is enhanced.

Abstract: A mixing and delivery system for supplying small particles suspended in a liquid to form a slurry for delivery and recirculation which includes a mixing tank having an inlet and an outlet, a pump having an inlet and an outlet, a sample cell having an inlet and an outlet, an ultrasonic flow cell having an inlet and an outlet, and a transition bushing having an inlet and an outlet. The sample cell has first and second generally rectangular planar opposed faces, the inlet of the sample cell is rectangular and defined by two opposed sides which are respectively part of the first and second generally rectangular planar opposed faces. The opposed sides are much longer in length than the intermediate opposed sides of the rectangular inlet. The outlet of the mixing tank is connected to the inlet of the pump and the outlet of the pump is connected to the inlet of the transition bushing by a circular cross section tube, that is coupled directly to the inlet of the sample cell.

Abstract: A multidimensional oscillation of an object carrier upon which a vessel containing a medium to be mixed can be placed, can have a X frame suspended by a pair of X leaf springs on a base plate and supporting a Y frame having leaf springs extending upwardly from the X frame and connected at the top of the Y springs by the X frame plate. The X frame can be mounted upon the Z frame oscillating in the Z direction and all oscillations can be induced by oscillating drives consisting of permanent magnets juxtaposed with exciting coils adjustable as to frequency, amplitude and phase.

Abstract: A stirring apparatus for an automatic chemical analysis system for analyzing a sample in a reaction vessel for obtaining an amount of a specific component of the sample. The stirring apparatus includes a stirring member formed as a vibrating member of a piezoelectric vibrator and having a flexible structure in the shape of an elongated strip or plate, a support unit for holding the stirring member in a perpendicularly suspended manner, a moving unit for moving the support unit together with the stirring member between the reaction vessel and a washing unit for washing the stirring member, a vibrating unit for vibrating the stirring member in a washing pool of the washing unit and in the reaction vessel and a control unit operatively connected to these units, respectively, for controlling operations of the respective units.

Abstract: An acoustic liquid processing device in the form of a vessel having an interior wall which surround a process liquid. An electrostatic film transducer is attached to the interior wall to substantially envelop a selected volume of the process liquid. The transducer's acoustic impedance is approximately equal to that of the process liquid. The transducer is energized to subject the process liquid to acoustic vibration.

Abstract: A device for mixing fluid materials using chaotic flow combined with sonic energy. The device includes sine wave baffles to produce mixing by folding, stretching and breaking the material as it continuously flows and simultaneously chopping the mixed material with vorticular motion using pressure fronts produced by sonic energy generators.

Abstract: Blend times of liquids are determined by measuring the rate of change in dielectric loss of stirred liquid media. The blend times for partial or complete mixing may be determined by this method, for example, mixing is essentially complete when the dielectric loss becomes constant. Tracer materials may be added to liquid mixtures to alter dielectric properties so that changes in the dielectric loss are readily measurable. This method may also be used to determine the blend times for dissolution and mixing of solid or gaseous materials with liquids.

Abstract: A generator for driving an ultrasonic transducer for use in ultrasonic cleaning. The generator is based on a voltage controlled oscillator which drives an output circuit which includes the ultrasonic transducer. The output circuit has a resonant frequency, and a resonance follower produces a control voltage which tunes the voltage controlled oscillator to the resonant frequency. Operating in conjunction with the automatic tuning elements is a constant power control which allows the user to set a desired power level, and monitors the actual output power by means of an output wattmeter circuit, to cause the actual output power to match the level selected by the user. The constant output power circuit is effective even during resonance tracking of the system, or during frequency modulation of the ultrasonic output energy.

Abstract: A shaking table for laboratory use for agitating liquid in flasks has at least one direct electromagnetic drive, for example, opposed pairs of electromagnets (14, 15) arranged orthogonally. A control device may control pulse frequency and amplitude to the electromagnets to produce different shaking modes. A plurality of drive members connected to an articulation mechanism are movable by the electromagnets, the articulation mechanism being mounted to the table. The table is mounted to a base by a plurality of flexible posts.

Abstract: Megasonic cleaning system for use in cleaning of electronic or other items such as semiconductor wafers or semiconductor substrates in a wafer carrier. Formed piezoelectric transducers are bonded to a tubular envelope at a low temperature and are excited at a first frequency or a second higher frequency for cleaning of items in a cleaning tank. A novel sealing assembly accommodates tubular envelopes of varying diameters.

Abstract: Method and apparatus for separating particles (1) which are dispersed in a dispersion medium, whereby an ultrasonic standing wave (3) is generated by means of a composite resonator in a vessel (8) containing dispersion (2), the frequency of said wave preferably being in the neighborhood of the characteristic frequency (f.sub.o). In order to achieve, a better separation of the particles it is provided that the amplitudes (V) of the sound particle velocity which appear in the sound field are chosen slightly smaller than the upper threshold amplitude (V.sub.max), and that pressure forces on the dispersed particles (1), which result from the acoustic stream of the dispersion medium caused by applied sound, are equivalent to the longitudinal holding forces of the dispersed particles (1) in the areas of the antinodes (11) and nodes (12), and furthermore that the frequency by means of which the composite resonator is driven is as precisely as possible tuned to one of the resonant frequencies (f.sub.n).

Abstract: A linear, direct-drive microelectronic bonding apparatus (10) provides a bondhead mounting plate (20), a stationary magnetic circuit (21), a moving coil (22), a primary wire clamp housing (23), a transducer mount (24), and a high frequency ultrasonic transducer (25) (above 100 kHz), and a capillary (26). Bondhead assembly (16) is configured to present a collective axial wire path bore (27) along which wire (12) is fed to bond site (28) for forming microelectronic bond interconnections at bond site (28). In accordance with the invention, collective wire path bore (27) provides a protected method of feeding wire (12) to bonding site (28), while magnetic circuit (21) and moving coil (22) provide actuation in a substantially linear downward direction towards the bonding site. In contradistinction, prior art bonding strokes, rather than being substantially linear, are arc-like due to the capillary and transducer being perpendicular to one another.

Abstract: An ultrasonic contact lens cleaning device has a housing with a hemispherical cover hingedly affixed to it. A container for a lens cleaning solution is mounted in the housing. An acoustic resonant structure in the housing is coupled to the container. The structure has piezoelectric components. A frequency modulated power circuit in the housing is electrically connected to and drives the acoustic resonant structure and provides a controlled level of ultrasonic cleaning energy.

Abstract: The method for acceleration of liquid and bulk materials comprises conversion of energy of the electromagnetic pulse of a radiator (1) into mechanical energy applied to the treated material by a plate element (3) of a conducting material having at least one degree of freedom in the direction of acceleration. The opposite surfaces of the place element (3) at the moment of emission of the electromagnetic pulse are brought in physical contact with the radiator and treated material, respectively.An apparatus for realization of the above method comprises a radiator (1) connected with a source (2) of electromagnetic pulses, a plate element (3) of a conducting material arranged loosely on the radiator (1), the surface of said element being intended for placement of the treated material.

Abstract: A stirrer for stirring a liquid in a container, which includes a stator; a rotor disposed in the container and provided with stirring vanes; and a cylindrical housing of nonmagnetic material having a peripheral wall thereof interposed between the stator and rotor and rotatably supporting the rotor through intervention of the liquid. This arrangement provides a stirrer of simple and compact construction, which can stir the liquid in a container completely in a closed state free of sliding portions of rotary components or shaft seal portions.

Abstract: An ultra-sonic weaving machine reed cleaner in which the cleaner is moved adjacent the weaving machine and the reed is cleaned without disturbing the thread-up of the warp yarn in the reed. The reed cleaner consists of three bins in which the reed consecutively is placed to wash it, rinse it and then blow it dry. A plurality of transducers are placed in contact with the bottoms of the washing and rinsing bins to enhance the action of the washing and rinsing fluid.

Abstract: A method of and an apparatus for mixing or dispersing particles with use of gradient force produced by a contact type electric field curtain. The particles are mixed or dispersed by permitting them to be put in a dielectric container and pass through the action area of the electric field curtain.

Abstract: A stirrer for stirring a liquid in a container, which includes a stator; a rotor disposed in the container and provided with stirring vanes; and a cylindrical housing of nonmagnetic material having a peripheral wall thereof interposed between the stator and rotor and rotatably supporting the rotor through intervention of the liquid. This arrangement provides a stirrer of simple and compact construction, which can stir the liquid in a container completely in a closed state free of sliding portions of rotary components or shaft seal portions.

Abstract: Fluid mixing apparatus includes a non-magnetic conduit (4) and a magnetically susceptible rod (5) which is contained in and extends longitudinally of the conduit. The rod is substantially not permanently magnetized. A least two electromagnets (6, 7) are positioned externally of the conduit so that each may, when activated, individually cause movement of the rod across the conduit. The electromagnets may be activated in turn and one at a time to induce an effective vibratory mixing motion of the rod within the conduit.

Abstract: A method and apparatus for cleaning printed electrical circuit boards having surface mount components by ultrasonic energy in the frequency range between 300 kHz and 1.0 MHz. The ultrasonic energy is produced by an array of piezoelectric wafers mounted to the inside surface of an immersible transducer assembly which, in turn, is disposed in a tank accommodating a bath of cleaning liquid. The ultrasonic energy provided by the transducer assembly and the circuit board to be cleaned are disposed to cause the ultrasonic wave beam to be incident upon a board to be cleaned at an angle of 90.+-.60 degrees relative to the surface plane of the board. This arrangement will remove solder flux residue and other contaminants from spaces ranging from 0.001 to 0.010 inch present underneath a surface mount component.

Abstract: A sonic generator comprises a resonant bar, a housing and magnetic excitation units connected between the resonant bar and the housing. The magnetic excitation units are connected to the bar at highly stressed points using a mounting connection which is a sleeve having an inside diameter slightly greater than the outside diameter of the bar. A resilient elastomer such as urethane is mounted between the sleeve and the resonant member. The sonic generator may be used for grinding purposes and, in particular, may be used to grind material exceptionally fine with reduced power consumption. The bar is substantially unrestrained so as to allow substantially free vibration.

Abstract: A magnetostrictive transducer comprising a plurality of elongated strips of magnetostrictive material, each strip having a proximal end, a distal end and a substantially V-shaped cross section wherein each arm of the V is formed by a longitudinal length of the strip, each strip being attached to an adjacent strip at both the proximal end and the distal end to form and integral substantially rigid column having a central axis with fins extending radially relative to said axis; and an ultrasonic resonant vibrator including such a transducer.