What does bending element actually mean

DE102013205626A1 - Bending transducer with piezoelectric bending element, cooling device and electronic module - Google Patents

Bending transducer with piezoelectric bending element, cooling device and electronic module Download PDF

info

Publication number
DE102013205626A1
DE102013205626A1DE102013205626.5ADE102013205626ADE102013205626A1DE 102013205626 A1DE102013205626 A1DE 102013205626A1DE 102013205626 ADE102013205626 ADE 102013205626ADE 102013205626 A1DE102013203206 A1DE 1026A201320320 A1DE
Authority
DE
Germany
Prior art keywords
bending
support
layer
deflection
bending transducer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
DE102013205626.5A
Other languages
English (en)
Inventor
Martin Honsberg-Riedl
Gerhard Mitic
Randolf Mock
Thomas Vontz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AGfiledCriticalSiemens AG
Priority to DE102013205626.5ApriorityCriticalpatent / DE102013205626A1 / de
Publication of DE102013205626A1publicationCriticalpatent / DE102013205626A1 / de
Withdrawnlegal-statusCriticalCurrent

Left

  • 238000005452bendingMethods0.000titleclaimsabstractdescription139
  • 238000001816coolingMethods0.000titleclaimsabstractdescription27
  • 239000010410layersSubstances0.000claimsdescription89
  • 239000000969carriersSubstances0.000claimsdescription55
  • 239000003570airSubstances0.000claimsdescription7
  • 230000000737periodicEffects0.000claimsdescription3
  • 239000000463materialsSubstances0.000description6
  • 239000004033plasticsSubstances0.000description6
  • 230000035882stressEffects0.000description6
  • 229920003023plasticsPolymers0.000description5
  • 230000003247decreasingEffects0.000description4
  • 239000004918carbon fiber reinforced polymerSubstances0.000description2
  • 230000001419dependentEffects0.000description2
  • 239000000945fillersSubstances0.000description2
  • 230000000051modifyingEffects0.000description2
  • 230000015572 biosynthetic processEffects0.000description1
  • 239000002131composite materialsSubstances0.000description1
  • 230000000875correspondingEffects0.000description1
  • 239000011152fibreglassSubstances0.000description1
  • 238000005755formation reactionsMethods0.000description1
  • 239000002184metalsSubstances0.000description1
  • 230000002028prematureEffects0.000description1
  • 230000000284 restingEffects0.000description1
  • 239000004065semiconductorsSubstances0.000description1

Images

Classifications

    • H-ELECTRICITY
    • H01 — BASIC ELECTRIC ELEMENTS
    • H01L — SEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L23 / 00 — Details of semiconductor or other solid state devices
    • H01L23 / 34 — Arrangements for cooling, heating, ventilating or temperature compensation; Temperature sensing arrangements
    • H01L23 / 46 — Arrangements for cooling, heating, ventilating or temperature compensation; Temperature sensing arrangements involving the transfer of heat by flowing fluids
    • H01L23 / 467 — Arrangements for cooling, heating, ventilating or temperature compensation; Temperature sensing arrangements involving the transfer of heat by flowing fluids by flowing gases, e.g. air
    • H-ELECTRICITY
    • H01 — BASIC ELECTRIC ELEMENTS
    • H01L — SEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L41 / 00 — Piezo-electric devices in general; Electrostrictive devices in general; Magnetostrictive devices in general; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L41 / 08 — Piezo-electric or electrostrictive devices
    • H01L41 / 09 — Piezo-electric or electrostrictive devices with electrical input and mechanical output, e.g. actuators, vibrators
    • H01L41 / 0926 — Piezo-electric or electrostrictive devices with electrical input and mechanical output, e.g. actuators, vibrators using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders
    • H01L41 / 0933 - Beam type
    • H01L41 / 094 Cantilever, i.e. having one fixed end
    • H-ELECTRICITY
    • H01 — BASIC ELECTRIC ELEMENTS
    • H01L — SEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L2924 / 00 — Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24 / 00
    • H01L2924 / 0001 — Technical content checked by a classifier
    • H01L2924 / 0002 — Not covered by any one of groups H01L24 / 00, H01L24 / 00 and H01L2224 / 00

Abstract

Description

  • The invention relates to a bending transducer, a cooling device and an electronics module.
  • Piezoelectric bending transducer modules with piezoelectric bending elements are used, for example, as piezoelectric wedlers, with the bending element of the bending transducer being excited to bending vibrations by applying a sinusoidal electrical voltage to the piezoelectric bending element in the frequency range of audible sound or infrasound (about 10 Hz to 1 KHz) usually corresponds to the lowest bending mode of the bending transducer. Particularly in the case of components in the form of bending beams, a uniform air flow is generated, for example in the direction of the longitudinal extension of the bending beam, as a result of the periodic movement of the bending element. In the case of heat sinks in cooling devices of electronic modules, this air flow can be used to increase the cooling capacity of the heat sink by flowing against cooling fins.
  • Compared to purely passive measures for cooling, piezoelectric bending transducer modules can reduce the structural volume of electronic modules and improve the energy balance, for example by improving the regularly highly temperature-dependent efficiency of semiconductor components.
  • In the case of electronic modules operated with fans, improvements have so far been achieved by optimizing the thermal or fluid-dynamic design of the electronic module. However, conventional fans are limited in their service life and, for example, do not reach the service life of electronic components such as high-performance LED lights (regularly at least 30,000 hours). Furthermore, cooling by fans, which typically cause disruptive noise emissions, is often not expedient in the case of electronic modules. Alternative solutions, on the other hand, do not yet achieve the required cooling efficiencies.
  • Piezoelectric bending transducers also regularly do not achieve the service life that is usual for electronic components such as LEDs.
  • It is therefore the object of the invention to specify a bending transducer, a cooling device and an electronics module which can be operated efficiently and with a long service life.
  • This object of the invention is achieved with a bending transducer with the features specified in claim 1, with a cooling device with the features specified in claim 13 and with an electronics module with the features specified in claim 14. Preferred developments of the invention emerge from the associated subclaims, the following description and the drawing.
  • The bending transducer according to the invention has a piezoelectric bending element which has at least one support structure which has a bending stiffness that varies along at least one direction.
  • With the bending transducer according to the invention, premature breakage of a piezoelectric bending element can be prevented after a comparatively short period of operation. In conventional flexural transducers, the cause of such a break is in particular mechanical stresses which are caused by the periodic deflection during a flexural oscillation. In conventional bending transducers, these occur when the air throughput is sufficiently high for sufficient cooling, and critical stresses for piezoceramic bending elements are exceeded. Mechanical stresses can be reduced considerably by the design of the bending transducer according to the invention. As a result of the flexural rigidity of the support structure of the bending element varying along at least one direction, however, the mechanical stresses occurring in the piezoelectric material of the bending element can be avoided by adapting the flexural rigidity of the support structure.
  • In the bending transducer according to the invention, the bending element expediently has a clamped area and a free end. The support structure expediently extends along at least part of the free end. In the case of bending transducers, it is precisely the end area of ​​the free end of a bending element that is subject to high spatial deflections, which decrease sharply from this end area to the clamped area. As a result of the support structure extending along at least part of the free end, the mechanical stresses caused by the deflection varying along this part of the free end can be limited in their amount.
  • In an advantageous development of the bending transducer according to the invention, the bending element has a layer structure, the layer structure comprising at least one piezoceramic layer and at least one carrier layer by means of which the carrier structure is formed. In this development of the invention, the bending element can be formed with an, in particular flat, piezoceramic layer. In particular, by means of a flat, expediently full-area, carrier layer attached to the piezoceramic layer, mechanical stresses can be limited along wide areas of the piezoceramic layer when the bending transducer is in operation.
  • In the bending transducer according to the invention, the layer structure of the bending element ideally comprises at least one first and at least one second piezoceramic layer and at least one carrier layer, the first and second piezoceramic layers being arranged on opposite sides of the carrier layer. The piezoelectric bending element is particularly advantageously designed as a bimorph which has an inner core layer which is formed by means of the at least one carrier layer or at least one of the carrier layers.
  • In the bending transducer according to the invention, the bending element is advantageously designed for deflection along a deflection direction, at least the piezoceramic layer and the at least one further carrier layer following one another along the deflection direction.
  • In the case of the bending transducer according to the invention, the bending element is ideally designed as a bending beam.
  • Particularly advantageously, the at least one piezoceramic layer and / or at least one carrier layer are each designed as a flat part and / or flat components and the flat extensions preferably extend almost or completely perpendicular to this deflection direction. In the context of this invention, an almost vertical extension is understood to mean an extension which deviates from a vertical direction by a maximum of 20 °, preferably by a maximum of 10 ° and ideally by a maximum of 3 °. In this development of the invention, the flexural rigidity can be varied particularly easily along the flat extension of the carrier layer and / or the piezoceramic layer with respect to bends in the deflection direction.
  • In the bending transducer according to the invention, the bending element particularly preferably extends away from its clamped area in an extension direction and the flexural rigidity of the carrier varies at least along this extension direction.
  • In the bending transducer according to the invention, the at least one support structure expediently has a flat extension and a varying thickness transversely to the flat extension. In particular, the at least one carrier structure has a varying thickness perpendicular to the flat extension, expediently perpendicular to a deflection direction as described above. If the material properties of the support structure are otherwise constant along the flat extension, the geometry varying along the flat extension leads in a simple manner to a bending stiffness that varies along the flat extension.
  • As an alternative or in addition to the development of the invention described above, in the bending transducer according to the invention the at least one carrier structure, at least macroscopically averaged, has a varying mass density. In this way, too, a varying flexural rigidity is easily achieved. A varying mass density means, on the one hand, that the mass density of the material varies on a microscopic length scale. In an advantageous development of the invention, however, the mass density can also vary averaged macroscopically, i.e. the averaged mass density varies at least over a macroscopic length that is smaller than the longitudinal extension of the bending element in the direction of extension. The material of the carrier structure according to the invention is preferably micro- and / or macroscopically structured, so that the mass density of the at least one carrier structure varies averaged over such a macroscopic length.
  • In particular, in the bending transducer according to the invention, the at least one support structure has recesses of varying diameter and / or varying clear width and / or varying cross-sectional area and / or varying geometric shape and / or varying local number and / or surface density.
  • In the bending transducer according to the invention, a thickness of the at least one support structure suitably varies transversely to a flat extension of the support structure and / or an at least macroscopically averaged mass density of the support structure or one of the support structures linearly or periodically, in particular harmonically, approximately sinusoidally.
  • In the bending transducer according to the invention, the bending element is expediently designed flat and has a corrugated shape in the rest state of the bending element, in particular a corrugated longitudinal section contour along the direction of extension and along the direction of deflection.
  • The cooling device according to the invention for cooling an electronic component comprises a bending transducer according to the invention as described above and a heat sink, the bending transducer being designed and arranged to cause an air flow directed onto the heat sink.
  • The electronic module according to the invention has an electronic component, in particular a power component, and a cooling device according to the invention as described above, which is designed and arranged to cool the component.
  • The invention is explained in more detail below using an exemplary embodiment shown in the drawing. Show it:
  • a bending element of a bending transducer of the prior art in the form of a bending beam, schematically in longitudinal section,
  • the bending element according to, in a state deflected along a deflection direction, schematically in longitudinal section,
  • a bending beam of a bending transducer according to the invention with a layer structure in the direction of deflection with a carrier layer with a mass density that varies harmoniously in the longitudinal direction of the bending beam, schematically in longitudinal section,
  • a bending beam of a further bending transducer according to the invention with a layer structure in the direction of deflection with a carrier layer with a mass density that varies linearly in the longitudinal direction, schematically in longitudinal section,
  • a bending beam of a further bending transducer according to the invention with a layer structure in the direction of deflection with a carrier layer with a thickness that varies harmoniously in the longitudinal direction in the direction of deflection, schematically in longitudinal section,
  • a bending beam of a further bending transducer according to the invention with a layer structure in the direction of deflection with a carrier layer with a thickness that increases linearly in the longitudinal direction in the direction of deflection, schematically in longitudinal section,
  • a bending beam of a further bending transducer according to the invention with a layer structure in the direction of deflection with a carrier layer with a thickness linearly decreasing in the direction of deflection in the direction of deflection, schematically in longitudinal section,
  • a bending beam of a further bending transducer according to the invention with a layer structure in the deflection direction with a carrier layer with a thickness linearly decreasing in the longitudinal direction in the deflection direction and with a longitudinal section contour undulating in the deflection direction and in the longitudinal direction, schematically in longitudinal section as well
  • a carrier layer of the bending beam of the bending transducer according to the invention according to schematically in a perspective illustration.
  • The bending element shown in FIGS. 1 and 2 of a known bending transducer is designed as a bending beam. The bending beam is clamped in a clamp (not explicitly shown) at one longitudinal end in a manner known per se. The bending beam extends from the restraint in the longitudinal direction L. Far from the restraint, the bending beam has a free end with an end region. The end region can be deflected in a deflection direction A perpendicular to the longitudinal direction L and in the plane of the drawing. Deflection states of the bending beam are shown in FIG.The bending beam shown in FIGS. 1 and 2 has a layer structure with a layer sequence in the direction of deflection A in a manner known per se.
  • The layer structure comprises a carrier layer, also known as a core layer, which extends flat and perpendicular to the direction of deflection A. The core layer can consist of various materials, such as metal or a plastic or a fiber-plastic composite, for example GRP plastic (glass fiber reinforced plastic) or CFRP plastic (carbon fiber reinforced plastic).
  • On each of the flat sides of the carrier layer facing away from each other, a piezoceramic layer, likewise perpendicular to the deflection direction A, is bonded over the entire surface, on the one hand a first piezoceramic layer and on the other hand a second piezoceramic layer. As a result of this flat design of the layers of the layer structure, the bending beam as such also has an essentially flat shape perpendicular to the direction of deflection A.
  • By means of this above-described layer structure, the bending beam forms a known bimorph.
  • The exemplary embodiments of bending beams of bending transducers according to the invention described below also have a layer structure as described above. Deviations in the shape and structure of the carrier layer and possibly corresponding piezoceramic layers are explained below with reference to FIGS.
  • The bending beam of a bending transducer according to the invention shown in FIG. 1 likewise has a layer structure in the direction of deflection A with a carrier layer. In contrast to the previously described example of the known bending beam, in the exemplary embodiment shown in FIG. 3, the mass density of the carrier layer in the longitudinal direction L varies harmonically, namely sinusoidally. The thickness of the carrier layer in the direction of deflection A is constant over the length L in the exemplary embodiment shown. For example, the carrier layer is produced by means of a plastic with a concentration of fillers modulated in the longitudinal direction L. Another exemplary implementation of a harmoniously varying mass density is explained in more detail in the following description of the figures with reference to FIG.
  • The bending beam shown in FIG. 3 of a further exemplary embodiment of a bending transducer according to the invention also has a layer structure in the direction of deflection A, as described above. In contrast to the exemplary embodiments described above, the mass density of the carrier layer varies linearly in the longitudinal direction. For example, the carrier layer is produced by means of a plastic with a concentration of fillers modulated in the longitudinal direction L.
  • The bending beam of a further exemplary embodiment of a bending transducer according to the invention also has a layer structure in the longitudinal direction A shown in FIG. In contrast to the exemplary embodiments described above, it is not the density of the carrier layer that varies, but rather the thickness of the carrier layer of the bending beam in the deflection direction A along the longitudinal direction L harmonically, here sinusoidally.
  • In the bending beam of a bending transducer according to the invention shown in FIG. 1, the thickness of the carrier layer varies linearly in the direction of deflection A along the longitudinal direction L. The thickness increases in the longitudinal direction L. In an alternative embodiment, the thickness of the carrier layer in the direction of deflection A does not vary linearly along the longitudinal direction L, but rather in the form of an exponential function, for example an exponential function that increases in the longitudinal direction L.
  • The bending beam shown in the figure of a further exemplary embodiment of a bending transducer according to the invention also has a layer structure in the direction of deflection A. The thickness of the carrier layer decreases linearly in the longitudinal direction L. The decreasing thickness of the carrier layer in the longitudinal direction L leads to a whip-like movement of the bending beam during its operation. In this way, the bending transducer of this exemplary embodiment achieves a particularly efficient air movement and air turbulence.
  • In the bending beam of a further exemplary embodiment of a bending transducer according to the invention shown in FIG. 3, the thickness of the carrier layer decreases in the deflection direction A in the longitudinal direction L. In the plane spanned by the deflection direction A and the longitudinal direction L, the carrier layer also has a corrugated longitudinal sectional contour. The thickness of the carrier layer, which decreases in the longitudinal direction L, leads to a whip-like movement of the bending beam, comparable to the embodiment shown in FIG. In this way, the bending transducer of this exemplary embodiment also achieves particularly efficient air movement and air turbulence.
  • The support layer of the bending beam shown in FIG. 4 represents an alternative implementation of the support layer according to with a harmoniously varying mass density. According to the mass density does not vary microscopically, but through holes extending through the support layer are made perpendicular to the flat extension of the support layer. In the exemplary embodiment shown, the through-holes are arranged along the two-dimensional extensions of the carrier layer in both rows and columns with respect to one another.
  • The through holes follow each other at right angles to the direction of deflection A and perpendicular to the longitudinal direction L with constant hole diameters. In the longitudinal direction L, on the other hand, the hole diameter of the through holes varies in such a way that a harmoniously varying flexural rigidity results.
  • The dimensions of the through holes are on average less than a tenth of the extent of the carrier layer in the longitudinal direction L. In the exemplary embodiment shown, the mass density of the carrier layer, averaged macroscopically, varies harmonically in the longitudinal direction L.
  • In exemplary embodiments that are not specifically shown, the through holes can also have longitudinal sections other than circular, for example in the form of elongated holes. Furthermore, instead of the hole diameter, the clear width, the spacing of the through holes from one another, the geometric shape of the through holes or the local number or surface density of the through holes can vary.
  • In exemplary embodiments that are not specifically shown, the through holes can be filled with one or more other materials, for example with an elastic module suitable for plastic.
  • Not specifically shown in the drawing, cooling devices according to the invention each comprise bending transducers according to the invention with piezoelectric bending elements as described above.
  • The cooling devices are each part of an electronic module according to the invention (not shown separately), which each has an electronic component in the form of a power component. The respective cooling device is designed to cool the component and to cool the component in thermal contact therewith.

Claims (14)

  1. Bending transducer with a piezoelectric bending element (;;;;;), characterized, that the bending element has at least one support structure which has a bending stiffness that varies along at least one direction (L).
  2. Bending transducer according to the preceding claim, in which the bending element (;;;;;) has a clamped area and a free end (14), the at least one support structure extending along at least part of the free end (14).
  3. Bending transducer according to one of the preceding claims, in which the bending element (;;;;;) has a layer structure with at least one piezoceramic layer (;) and at least one carrier layer (;;;;;), by means of which the carrier structure is formed.
  4. Bending transducer according to the preceding claim, in which the layer structure has at least one first () and at least one second piezoceramic layer () and at least the carrier layer, the first and second piezoceramic layers being arranged on opposite sides of the carrier layer (;; ;;) .
  5. Bending transducer according to the preceding claim, in which the bending element (;;;;;) is designed for deflection along a deflection direction (A) and at least the piezoceramic layer (;) and the at least one carrier layer (;;;;;) along the deflection direction (A) follow one another.
  6. Bending transducer according to one of the preceding claims, in which the at least one piezoceramic layer (;) and / or carrier layer (;) is in each case designed as a flat part and / or flat component and the flat extension in each case extends at least also, preferably almost completely, perpendicular to the direction of deflection ( A) extends.
  7. Bending transducer according to one of the preceding claims, in which the bending element (;;;;;) extends from its clamped area in an extension direction (L) and in which the flexural rigidity of the support structure varies at least along the extension direction (L).
  8. Bending transducer according to one of the preceding claims, in which the at least one support structure has a flat extension and a varying thickness transversely to the flat extension.
  9. Bending transducer according to one of the preceding claims, in which the carrier structure has a mass density that varies, at least macroscopically averaged.
  10. Bending transducer according to one of the preceding claims, in which the support structure has recesses (10) of varying diameter and / or of varying lightness and / or varying cross-sectional area and / or varying geometric shape and / or varying local number and / or surface density.
  11. Bending transducer according to one of the preceding claims, in which a thickness of the support structure transversely to a flat extension of the support structure, in particular perpendicular to the flat extension of the at least one support structure, and / or the at least macroscopically averaged mass density of the support structure is linear or periodic, in particular harmonious, varies.
  12. Bending transducer according to one of the preceding claims, in which the bending element (;;;;;) is designed for deflection along a deflection direction (A) and in which the support structure has a corrugated shape in the direction of the deflection direction.
  13. Cooling device for cooling an electronic component, comprising a bending transducer according to one of the preceding claims and a heat sink, the bending transducer being designed and arranged to cause an air flow directed onto the heat sink.
  14. Electronics module with an electronic component, in particular a power component, and with a cooling device according to one of the preceding claims, which is designed and arranged to cool the component.
DE102013205626.5A2013-03-282013-03-28Bending transducer with piezoelectric bending element, cooling device and electronic module WithdrawnDE102013205626A1 (de)

Priority Applications (1)

Application NumberPriority DateFiling dateTitle
DE102013205626.5ADE102013205626A1 (de) 2013-03-282013-03-28Bending transducer with piezoelectric bending element, cooling device and electronic module

Applications Claiming Priority (1)

Application NumberPriority DateFiling dateTitle
DE102013205626.5ADE102013205626A1 (de) 2013-03-282013-03-28Bending transducer with piezoelectric bending element, cooling device and electronic module

Publications (1)

ID = 51519788

Family Applications (1)

Application NumberTitlePriority DateFiling date
DE102013205626.5AWithdrawnDE102013205626A1 (de) 2013-03-282013-03-28Bending transducer with piezoelectric bending element, cooling device and electronic module

Country Status (1)

Cited By (1)

Publication numberPriority datePublication dateAssigneeTitle
WO2017195014A1 (en) *2016-03-012017-11-16Vermon S.A.Piezoelectric energy harvester system with composite shim

Citations (10)

Publication numberPriority datePublication dateAssigneeTitle
US2900536A (en) *1954-11-181959-08-18Astatic Corp.Design of electro-mechanical transducer elements
DE2444647A1 (de) *1974-09-181976-04-08Siemens AGPiezoelectric bending transducer
DE3016748A1 (de) *1979-05-021980-11-13Sony Corp.Electromechanical converter
JPH0262085A (en) *1988-08-291990-03-01Matsushita Electric Ind Co LtdCeramic actuator
US20060138905A1 (en) *2004-12-282006-06-29Gonzales Christopher APiezoelectric fan for an integrated circuit chip
US7166952B2 (en) *2001-09-272007-01-231. . . LimitedPiezoelectric structures
US20070114890A1 (en) *2005-11-232007-05-24Churchill David LSlotted beam piezoelectric composite
US20090004034A1 (en) *2007-06-292009-01-01Seri LeePiezoelectric fan
US8129887B2 (en) *2009-01-302012-03-06The Curators Of The University Of MissouriSystem and method for harvesting energy from environmental vibrations
DE102010041200A1 (de) *2010-09-222012-03-22Siemens AktiengesellschaftPiezoceramic bending transducer

Patent Citations (10)

Publication numberPriority datePublication dateAssigneeTitle
US2900536A (en) *1954-11-181959-08-18Astatic Corp.Design of electro-mechanical transducer elements
DE2444647A1 (de) *1974-09-181976-04-08Siemens AGPiezoelectric bending transducer
DE3016748A1 (de) *1979-05-021980-11-13Sony Corp.Electromechanical converter
JPH0262085A (en) *1988-08-291990-03-01Matsushita Electric Ind Co LtdCeramic actuator
US7166952B2 (en) *2001-09-272007-01-231. . . LimitedPiezoelectric structures
US20060138905A1 (en) *2004-12-282006-06-29Gonzales Christopher APiezoelectric fan for an integrated circuit chip
US20070114890A1 (en) *2005-11-232007-05-24Churchill David LSlotted beam piezoelectric composite
US20090004034A1 (en) *2007-06-292009-01-01Seri LeePiezoelectric fan
US8129887B2 (en) *2009-01-302012-03-06The Curators Of The University Of MissouriSystem and method for harvesting energy from environmental vibrations
DE102010041200A1 (de) *2010-09-222012-03-22Siemens AktiengesellschaftPiezoceramic bending transducer

Cited By (2)

Publication numberPriority datePublication dateAssigneeTitle
WO2017195014A1 (en) *2016-03-012017-11-16Vermon S.A.Piezoelectric energy harvester system with composite shim
US10097112B2 (en) 2016-03-012018-10-09Vermon S.A.Piezoelectric energy harvester system with composite shim

Similar documents