Showing papers on "Bimorph published in 1989"

Integrated scanning tunneling microscope

Abstract: There is disclosed herein an integrated scanning tunneling microscope and an integrated piezoelectric transducer and methods for making both. The device consists of one or two arm piezoelectric bimorph cantilevers (42, 46) formed by micromachining using standard integrated circuit processing steps. These cantilevers are attached to the substrate (32) at one area (80) and are free to move under the influence of piezoelectric forces which are caused by the application of appropriate voltages generated by control circuitry (88) and applied to pairs of electrodes (48, 36, 44; 52, 49, 44) formed as an integral part of the bimorph cantilever structure. The electric fields caused by the control voltages cause the piezoelectric bimorphs to move in any desired fashion within ranges determined by the design. The bimorph cantilevers have tips (66) with very sharp points formed thereon which are moved by the action of the control circuit (88) and the piezoelectric bimorphs so to stay within a very small distance of a conducting surface (84). The movements of the tip can be tracked to yield an image of the surface at atomic resolution.

Applications of silicon microactuators based on bimorph structures

Abstract: Microactuators for electromechanical signal conversion are described. Basic elements of the transducer are a bimorph structure and an integrated heat source. Due to the differences of the coefficients of thermal expansion, a temperature-controlled deformation of the the bimorph structure occurs. Bulk and surface micromachining techniques can be used to achieve an object displacement perpendicular to or within the substrate plane. The main advantages of this class of actuators are simple fabrication processes and operation at standard IC (integrated circuit) voltage levels, allowing further system integration. The conversion characteristics are described, and the application of these transducers for microvalves, optical components, manipulators, and motors is discussed. >

Hysteresis-free piezoelectric actuators using LiNbO3 plates with a ferroelectric inversion layer

Abstract: Heat treatment of a bare single-domain lithium niobate plate at somewhat lower temperatures than the Curie temperature causes a local polarization reversal, thereby yielding a ferroelectric inversion layer. The plate with such an inversion layer can serve as a piezoelectric actuator similar to the bimorph, because the piezoelectric constants in the inversion layer are opposite in sign to the original ones. This paper reports the characteristics of the bending actuators using 140° rotated Y-cut LiNbO3. Experimental results show that the actuator characteristics have excellent linearity, no hysteresis, and little creep, and therefore they are suitable for precise position control.

Magneto-optical recording and reproducing disk device having a bimorph type actuator with specific structures for mounting a magnetic head in opposing to the surface of the disk

Abstract: Magneto-optical disk recording and reproducing devices and actuators and distance detectors for use therewith are disclosed. The magneto-optical disk device includes a bimorph type actuator or an electromagnetic actuator for driving the magnetic head of the magneto-optical disk device. The bimorph actuator has a metallic shim having a width that varies with respect to the longitudinal distance in inverse proportion to the normal function of the first or the second free natural vibration mode. Alternatively, the bimorph type actuator has a recess formed on a bimorph element to expose a piezoelectric portion which outputs a voltage corresponding to the acceleration of the vibration of the actuator. The driver circuit of the actuator reduces the driving voltage when the frequency of the voltage generated at the recess comes into the neighborhood of a higher resonance frequency of the actuator. The optical distance detector comprises a light-emitting diode and a pair of photodiodes which detects the amount of light incident thereon after the light is reflected from a surface of an object the distance to which is measured. The geometric parameters of the photodiodes are selected such that the output of a first photodiode decreases as the measured distance increases while the output of a second photodiode increases as the measured distance increases. Thus, the normalized differential output of the two photodiodes, from which the measured distance is determined, varies substantially linearly with respect to the measured distance. In preferred forms, the photodetectors have stepped concentric configurations so that small distances can be measured accurately and efficiently.

Segmented bimorph deformable mirror

Abstract: The efficient low-voltage bending properties of PZT bimorph wafers have been combined with conventional microelectronics techniques to produce a 37-hex-faceted deformable mirror 23 mm in diameter and 1 mm thick. Despite the high ratio of diameter to thickness, at 633 nm an overall flatness of better than one-half wave peak-to-valley (PV) and one-tenth wave RMS is attained under an active figure control of about 7 V per wave. Evaporative deposition of the electrical contact pattern eliminates mechanical coupling to the bimorph and allows the device to perform to frequencies in excess of 10 kHz.

Piezoelectric bimorph-based translation device for two-dimensional, remote micropositioning

Abstract: We describe a two‐dimensional, remote micropositioning device that uses the bending mode of a piezoelectric bimorph for walking in the forward/reverse direction of motion. For this mode of operation step sizes range from ∼50 to 5000 nm, with a voltage sensitivity of ∼10 nm/V. Speeds of about 1 mm/s are possible. In the lateral direction of motion, the linear extension mode of the bimorph is used, giving step sizes from ∼50 to 1000 nm, with a sensitivity of ∼2 nm/V. For the walking sequence, anodized aluminum feet are electrostatically clamped to an anodized aluminum baseplate. When used as the coarse positioner in a scanning tunneling microscope, the device requires less than 100 V operating voltage, thus eliminating the high‐voltage supply needed for previous piezoelectric walking devices. A circuit diagram for ‘‘joystick’’ control of the micropositioner is also described.

Improved piezoelectric relay element and method for driving the same

Abstract: A piezoelectric relay element (322) is provided that engages contacts (335)(337). The relay element is constructed from a bimorph bender element (323) having a top electrode (332), a bottom electrode (334) and a center electrode (339). The center electrode (333) is driven to provide the bending motion associated therewith. The relay element (322) and its associated drive circuit (300) is simpler, less expensive, and more reliable than previous piezoelectric relays.

Actuator for driving optical element

Abstract: PURPOSE:To stabilize the driving characteristics of the actuator and to prolong the life by forming the intersection part of a nearly cross-shaped metallic thin plate as a mount part for an optical element, sticking piezoelectric substrates on leg parts, and also providing specific easy-to-bend parts CONSTITUTION:The metallic thin plate 2 is formed by blanking a nickel alloy plate of about 01mm in thickness in an almost cross shape and the center of its intersection part 3 is used as the optical element mount part by boring a mirror fitting part 5 The piezoelectric ceramic substrates 6 which are about 02mm thick are stuck on both surfaces of leg parts 4 of the metallic thin plate 2 to form a piezoelectric curvature part in bimorph structure Then, coupling parts 7 between the intersection part 3 and leg parts 4 are made narrowest in width and bent in an inverted V shape to form the easy-to-bent part in spring structure Thus, the driving efficiency of the optical element is improved and the coupling part 7 is easily formed in solid structure

High-resolution acoustic measurements in fluids and gases by a path length modulation technique

Abstract: An acoustic technique has been developed that permits high-resolution velocity measurements to be performed in liquids and gases under circumstances where the acoustic attenuation may become very large. This cavity resonance method has been demonstrated in cavities with lengths as small as 150 µm at acoustic frequencies up to 151 MHz. The acoustic path length is continuously adjusted by a piezoelectric bimorph controlled by feedback from a sensitive acoustic impedance spectrometer. The measurement of velocity then simply reduces to measurement of position of the bimorph, and this can be performed with high accuracy using a capacitance bridge. Absolute measurements of the attenuation of sound can also be performed with this arrangement. It is suggested that this approach will be useful for the study of collective excitations in quantum fluids.

Utilization of piezoelectric stiffened effects on impact printer heads

Abstract: The electromagnetic printer head has traditionally been used in the impact dot-matrix printer based on the electromagnetic attractions. The traditional technique, however, is approaching its limit. To find a break-through for this limit, efforts have been made to develop a printer head based on the piezoelectric effect. So far, however, there has not been realized a piezoelectric printer head with a better performance than that of the electromagnetic printer head. This paper discusses the direction to be aimed at by the high-performance printer head based on the piezoelectric effect. The reported direction can be summarized as the use of the longitudinal stiffened piezoelectric effect, instead of the transversal piezoelectric effect considered in the past, as well as the use of the lever mechanism which is isolated structurally from the piezoelectric element, instead of the traditional bimorph structure. The first piezoelectric printer head for some commercial printer products has already been successfully fabricated based on the essential idea in this paper, indicating its practical usefulness.

Support mechanism, support system, assembly method and assembly device using thereof

Abstract: PURPOSE: To softly hold a small part in vacuum by taking at least one part of two superposed plate like bodies as a bimorph type piezoelectric element. CONSTITUTION: A pair of the bimorph type piezoelectric elements 1a, 1b worked in a wedge type are superposed to form a pincette mechanism. Namely, a set of wedge type figures are cut off lineally symmetrically from a sheet of the piezoelectric element plate, superposed so that the curving direction to the polarity of an impressing voltage becomes conflicting and the opening and closing motion of the pincette tip is enabled. In the case of the power pinching a sample being short, the output voltage polarity of a power source 2 is changed to curve the piezoelectric elements 1a, 1b to the inside and the pinching power is increased. In the case of gripping a larger sample and optimizing the contact state of the pincette and sample, a spacer may be inserted between two sheets composing the pincette. COPYRIGHT: (C)1991,JPO&Japio

Recording and reproducing optical disk device

Abstract: Magneto-optical disk recording and reproducing devices and actuators and distance detectors for use therewith are disclosed. The magneto-­optical disk device comprises, in addition to the usual elements, a bimorph type actuator 9, 71 or an electromagnetic actuator 108-115 for driving the magnetic head 8 of the magneto-optical disk device. The bimorph actuator may have a metallic shim 74 whose width varies with respect to the longitudinal distance inversely proportional to the normal function of the first or the second free natural vibration mode. Alternatively, the bimorph type actuator may have a recess 9d formed on a bimorph element 9a to expose a piezoelectric ceramics which outputs a voltage corresponding to the acceleration of the vibration of the actuator; the driver circuit 96 of the actuator reduces the driving voltage when the frequency of the voltage generated at the recess comes into the neighborhood of a higher resonance frequency of the actuator. The optical distance detector comprises a light-emitting diode 14, 16, 31 and a pair of photodiodes 15, 17, 30 which detect the amount of light incident thereon after being reflected at a surface of an object the distance to which is measured. The geometric parameters of the photodiodes are selected in such a manner that the output of a first photodiode decreases as the measured distance increases while the output of a second photodiode increases as the measured distance increases. Thus, the normalized differential output of the two photodiodes, from which the measured distance is determined, varies substantially linearly with respect to the measured distance. In preferred forms, the photodetectors have stepped concentric configurations so that small distances can be measured accurately and efficiently.

Bimorph PZT Active Mirror

Abstract: about one wave P -V independent of voltage.Temperature introduces an average curvature or focus change similar to that caused by applied voltage, as shown inFigure 3. The device is first flattened by cooling to 7 °C; then as it is gradually warmed back to 25 °C the focus error returnsto several waves P -V. The "Power Removed" curve shows that after removal of the focus (power) term the residual figureerror is independent of temperature.

Thermal lens correction in a solid-state laser using a flexible bimorph mirror

Abstract: The resonator of a YAG:Nd3+ laser was used as an example to demonstrate the possibility of correcting the lowest aberrations of a thermal lens by an adaptive bimorph mirror. A fivefold reduction in the thermal lens astigmatism and of certain other aberrations was achieved at laser pump currents in the range 10 to 34 A.

Cooling device of video endoscope

Abstract: PURPOSE: To eliminate a dark current of a solid-state image pickup element and to make an S/N satisfactory by providing a pump for feeding out a fluid for cooling the solid-state image pickup element in an endoscope. CONSTITUTION: A bimorph piezoelectric pump 22 for feeding out a cooling fluid to a solid-state image pickup element 16 provided in a tip part 11 of an inserting part is provided in the inserting part. the bimorph piezoelectric pump 22 can be formed in a very small size, and accordingly, can be provided in a free space in the tip part 11 of the inserting part, and can be used under a high temperature environment in a state that the tip part 11 of the inserting part is cooled, without forming the diameter of the tip part 11 of the inserting part to a large diameter. In such a way, a dark current of the solid-state image pickup element 16 is eliminated and an S/N can be made satisfactory. COPYRIGHT: (C)1990,JPO&Japio

Batio3 Domain Bimorph Actuator

Abstract: Based on Forsbergh's experiment on the 90° laminar domain pattern in BaTiO3 crystal, a new type of bimorph actuator, BaTiO3 domain bimorph, was made and its properties were studied. By creating a large lateral strain in BaTiO3 crystal, this new type of actuator is able to produce a much larger displacement compared with the conventional piezoelectric bimorph with similar dimension. As a consequence, this new actuator has a higher loading ability as far as the displacement of the bimorph concerned. The experimental result also shows that the bimorph can be operated at least up to 1 KHz.

Cyclic fatigue testing device for fine ceramics by using piezo-electric bimorph actuator.

Abstract: A cyclic fatigue testing device by using a piezo-electric bimorph actuator has been investigated to evaluate cyclic fatigue phenomena of fine ceramics under cyclic loading at high frequencies. The bimorph was constructed as a cantilever. A large deflection induced by input voltage at the resonant frequency is applied as a stress amplitude to a ceramic testpiece placed on the fixture of a three point bending apparatus. This device has the following features.(1) Frequency could be changed between 100 and 580Hz by changing a frequency adjusting weight.(2) Stress amplitude could be changed 0 to 65kgf by controlling input voltage.

Piezoelectric bimorph type actuator

Abstract: PURPOSE:To spread the displacement by coaxially forming a plurality of slots along the circumferential direction to a metal plate. CONSTITUTION:With two pieces of disc piezoelectric plate 11 and 12 having electrodes in all regions both inside and outside, a metal plate 13 of the same size is put between them. To this plate 13 a plurality of slots are opened along the circumferential direction. Both piezoelectric plates 11 and 12 with the plate 13 put between them are stuck together with adhesive such as epoxy resin to make a bimorph. Furthermore, a piece of metal plate 15 is bent and put from outside between two pieces of piezoelectric plates 11 and 12 and stuck with adhesive. A half section 15a of the metal plate 15 forms the same slots to the disc body as the slots 14, while the other half 15b forms the disc body in a circular ring. By fixing the outside circumferential section and applying voltage, its actuator is used as a mechanism to obtain quantity of displacement in the center section with the bimorph flexed and deformed.

Method of driving piezoelectric actuator

Abstract: PURPOSE: To make more usable a piezoelectric actuator by producing a larger displacement by utilizing the behavior characteristics of spontaneous polarization existent in a piezoelectric ceramics crystal with respect to an electric field. CONSTITUTION: Deformation of piezoelectric ceramics produced as an electric field is applied to the piezoelectric ceramics is taken out utilizing a B-D region in the figure. Upon driving the actuator, the operation is once returned to a point D from a point C by applying the reverse polarity electric field, and thereafter it passes through a point F where the electric field is made zero, and further it moves to a point B by applying the forward polarity electric field. The operation is further returned to the point C by making the electric field zero, and in that case a maximum distortion which can be taken out is indicated by a point Z in the figure. The distortion is a point Y taking the point F as a reference. Hereby, greater distortion is produced, which is very effective in expanding the distortion of a laminate element, a bimorph element and the like for example. COPYRIGHT: (C)1990,JPO&Japio

Protected piezoelectric polymer bimorph

Abstract: A flexing piezoelectric bimorph (10) is formed, preferably from piezoelectric polymers (14, 16) having two metallized surfaces (19, 20), by bonding together two metallized surfaces (19, 20) to provide a pair of piezoelectric polymer layers (14, 16) arranged with substantially similarly oriented polarization. The outwardly facing metallized layers (22, 24) bonded on the opposite facing surfaces from the other two conducting layers of the bimorph. The control circuit (12) is connected so that applied potential and the outwardly facing two conducting layers (22, 24) are connected to ground in order to drain away static charge and shield the polymers (14, 16) from extraneous electric fields. The control potential (34) is electrically connected to the interposed central metallized layers (19, 20) which are bonded together and form the second electrode (18) for applying the appropriate electric fields to the bimorph (10).

Piezoelectric ceramic gripper

Abstract: PURPOSE: To produce relatively small gripping force by applying an alternating- current voltage of a prescribed frequency to a piezoelectric ceramic bimorph to vibrate its vibrating bodies. CONSTITUTION: All internal electrodes 2 are exposed out on the front face 4 of piezoelectric ceramics 1 for a PA element, and an insulating protection 5 of a glass film is formed over every two layer of the internal electrodes 2 and an external electrode 6 is applied over the insulating protections 5, to which external electrode 6 a lead wire is connected, for the formation of a laminated piezoelectric actuator element. This laminated piezoelectric actuator element situated at the middle of the main body is integrally formed at its sides 9 and 10 with levers as vibrating bodies, which have a chucking part at their tips 11 and 12. An alternating-current electric field of a prescribed frequency is impressed to the laminated piezoelectric actuator element to vibrate the levers are displace the chucking parts at the tips 11 and 12, which then grip an object with small gripping force.

Color display element

Abstract: PURPOSE:To display neutral tints with a very low power consumption by sticking two piezoelectric sheet materials whose front and rear faces a thin film electrode is stuck and providing an optical interference filter on a part of a bimorph which is displaced in proportion to the voltage applied to the thin film electrode. CONSTITUTION:Two piezoelectric sheet materials 11 and 12 of which thin film electrodes 13-15 are stuck to front and rear faces are stuck to each other, and a piezoelectric element (bimorph) 16 is displaced in proportion to the voltage applied to thin film electrodes 13-15, and an optical interference filter 17 is provided on a part of this bimorph 16. The optical interference filter 17 is attached to the displacing front end part of the bimorph 16, and the applied voltage is controlled to change an angle theta of the front end of the bimorph 16. Thus, neutral tints are displaced with a low power consumption because the interference filter 17 is displaced to change the light transmission spectrum characteristic by the visual angle.

Piezoelectric type fluid jetting nozzle

Abstract: PURPOSE:To eliminate a valve for preventing backflow by providing at least two or more bimorph forming sections fixed partly ion a fluid channel in a manner to generate a displacement in the direction in which a fluid introducing opening and a fluid opening are provided. CONSTITUTION:At least one or more of fluid introducing opening 15 and a fluid jetting opening 16 in which a fluid channel 11 is formed are provided, and at least two or more of bimorph type forming sections 13 and 14 fixed partly are provided in the fluid channel 11 in a manner as to generate a displacement in the direction in which said fluid introducing opening 15 and fluid jetting opening 16 are provided. The bimorph forming section is a laminated layer consisting of a material turning into a piezoelectric material by sintering and a material turning into a conductive material by sintering. A pump to flow the fluid in a constant direction can be formed by shifting the time of driving said independent bimorphs, and said pump works not to generate backflow and to prevent the two bimorphs working at that time from generating backflow. A valve for preventing backflow, therefore, is not necessary.

Analysis of piezoelectric ceramic bending vibrators using interdigital electrodes both for poling treatment and for AC excitation

Abstract: The single-plate ceramic bending vibrator, using interdigital electrodes for poling and excitation, has the remarkable features of high performance and reliability with little spurious response. This is in sharp contrast to the traditional bending vibrators with bimorph structure. This study aims at the description of the design principle for the bending vibrator with interdigital electrodes. A theoretical analysis is made using the conformal mapping, and a detailed discussion is presented on the relation of the capacitance ratio to the electrode dimensions and the poling voltage. Then the optimum condition is derived. A good agreement was observed by comparing the result of analysis and the experiment. It is shown that the capacitance ratio is less for the transversal coupling-type bending vibrator, with the electrode finger being parallel to the direction of elongation, than for the longitudinal coupling type with the perpendicular direction.

Head with slider

Abstract: PURPOSE:To perform the micro travel of a head chip and the fine adjustment of the amount of protrusion of the head chip from a slider plane in a slider by the defective function of a bimorph piezoelectric element by arranging the head chip at the open end of a hole opened on the slider plane by being fixed at the tip of the bimorph piezoelectric element. CONSTITUTION:The energizing of the bimorph piezoelectric element 13 in a head 5 with the slider is controlled at a control circuit 21, and the tip 13b of the piezoelectric element 13 is deflected freely in the tracking direction (b) of a floppy disk 6, and the micro travel of the head chip 14 in the tracking direction (b) is performed by the deflective function of the element. Also, at this time, the tip 13b of the piezoelectric element 13 performs circular motion centering an end part 13a, and the fine adjustment of the head chip 14 in a direction of arrow head (c) that is the protrusive direction of the slider plane 11a of the slider 11 can also be performed. And the micro travel of the head chip 14 and the fine adjustment of the amount of protrusion of the head chip 14 from the slider plane 11a can be performed by the deflective function of the tip 13b of the piezoelectric element 13.

Piezoelectric bimorph device

Abstract: PURPOSE:To create a banding deformation only by applying a forward electric field the same as the field at the time of polarization treatment by a method wherein flat plane electrodes are formed on both the surfaces of one piezoelectric ceramic plate and comb-shape electrodes facing each other are formed on one surface of the other piezoelectric ceramic plate opposite to the other surface to be bonded CONSTITUTION:Plane-shape Ag electrodes 4a and 4b are formed on both the surfaces of a piezoelectric ceramic plate 2a Comb-shape Ag electrodes 6a and 6b facing each other are formed only on one surface of a piezoelectric ceramic plate 2b The piezoelectric ceramic plates 2a and 2b are bonded to both the surfaces of an elastic metal plate 3 so as to make the comb-shape electrode forming surface come to the free surface side of a bimorph device A +terminal 7a and a -terminal 7b are lead out of the electrodes 6a and 6b The polarization P of the piezoelectric ceramic plate 2a is formed along the thickness direction of the piezoelectric ceramic plate by a polarization treatment and the polarization P of the piezoelectric ceramic plate 2b is formed along the direction from the +electrode 6a to the -electrode 6b If a forward electric field which has the same polarity as the polarity of the polarization treatment is applied to the polarized plates 2a and 2b, a piezoelectric lateral effect and a piezoelectric vertical effect are applied to the plates 2a and 2b respectively to create a bending deformation so that the device with a large deformation and induced force can be obtained

Floating head loading mechanism

Abstract: PURPOSE:To eliminate a head crash and the adhering of a head by providing a piezo bimorph in a board shape to move a floating head slider in a direction vertical to a lubricant surface and a laminating piezo actuator to move the floating head slider in a direction parallel to the lubricant surface. CONSTITUTION:Between an arm 6 and a suspension spring 1, a piezo bimorph 3 in the board shape and a laminating piezo actuator 5 to be expandable and contractable in a surface parallel to a magnetic disk medium 9 surface are joined, a floating head slider 8 is set in a condition separated from a medium surface in the middle of the stop of the magnetic disk medium 9, a proper voltage is given to the piezo bimorph 3 when the rotation of the magnetic disk medium 9 reaches a speed sufficient for the floating of a floating head, and the head is made to approach up to the medium 9 vicinity. Thereafter, a head loading is speedily executed by a negative pressure force generated at a negative pressure utilizing type floating head, and next, the head is moved by a control device 10 so that a position deviation between the head and a track can be made small by the actuator 5. Thus, the head crash and adhering can be eliminated.

Piezoelectric valve device

Abstract: PURPOSE: To smoothly actuate a valve unit in a small size with a large amount of displacement and large force by press-moving the valve unit by deflection in a direction of obverse and reverse of a tongue-shaped part having a bimorph piezoelectric element. CONSTITUTION: When total piezoelectric element 40 are electrified through a pair of lead terminals 61, 62, the one piezoelectric element is extended and the other piezoelectric element is contracted because a bimorph piezoelectric element is constituted such that the piezoelectric elements 40, adhesively attached to the obverse and reverse of a tongue-shaped part 32, are provided with polarity reversely in the obverse and reverse. In this way, four sheets of the tongue-shaped parts 32 are deflected in the axial direction of a valve unit 20, and it is lifted to the upper through a flange 20a by a point end member of the tongue-shaped part 32 with fuel injected by detaching the point end of the valve unit 20 from a fuel injection port 80a. Next, when electrification to the piezoelectric element is cut off, four sheets of the tonque-shaped parts 32 are given no deflection, and the fuel injection port 80a is closed by press- moving the valve unit 20 downward by a spring 82. COPYRIGHT: (C)1991,JPO&Japio

Separation membrane device

Abstract: PURPOSE:To prevent the clogging of the open cell of a separation membrane and to improve the permeability by providing a sheet-shaped piezoelectric body around the separation membrane, and vibrating the piezoelectric body. CONSTITUTION:The outer periphery of the porous separation membrane 2 is supported by a supporting body 4. The proximity of the outer periphery of the separation membrane 2 is clamped by a couple of the sheet-shaped piezoelectric bodies in the form of a doughnut. The separation membrane 2 is formed by a polymeric thin film including a polymeric mesh. The piezoelectric body 6 has a bimorph structure or a unimorph structure. The piezoelectric body 6 is vibrated by impressing a high-frequency voltage on the piezoelectric body 6, and the material deposited on the separation membrane 2 is removed. In addition, even when the piezoelectric body is fixed to one side of the separation membrane 2, the same result can be obtained.