[go: up one dir, main page]

WO2025098889A1 - Dispositif de production de son basé sur un système micro-électromécanique - Google Patents

Dispositif de production de son basé sur un système micro-électromécanique Download PDF

Info

Publication number
WO2025098889A1
WO2025098889A1 PCT/EP2024/080946 EP2024080946W WO2025098889A1 WO 2025098889 A1 WO2025098889 A1 WO 2025098889A1 EP 2024080946 W EP2024080946 W EP 2024080946W WO 2025098889 A1 WO2025098889 A1 WO 2025098889A1
Authority
WO
WIPO (PCT)
Prior art keywords
flexible
cantilevers
producing device
sound producing
mems
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.)
Pending
Application number
PCT/EP2024/080946
Other languages
English (en)
Inventor
Josef HANSSON
Jonatan WÅRDH
Serguei Smirnov
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.)
Myvox AB
Original Assignee
Myvox AB
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 Myvox AB filed Critical Myvox AB
Publication of WO2025098889A1 publication Critical patent/WO2025098889A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00—Piezoelectric transducers; Electrostrictive transducers
    • H04R17/02—Microphones
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K9/00—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers
    • G10K9/12—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated
    • G10K9/122—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated using piezoelectric driving means
    • G10K9/125—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated using piezoelectric driving means with a plurality of active elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
    • B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
    • B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
    • B06B1/0622—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00—Piezoelectric transducers; Electrostrictive transducers
    • H04R17/005—Piezoelectric transducers; Electrostrictive transducers using a piezoelectric polymer
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R31/00—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
    • H04R31/003—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor for diaphragms or their outer suspension
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/20—Piezoelectric or electrostrictive devices with electrical input and mechanical output, e.g. functioning as actuators or vibrators
    • H10N30/204—Piezoelectric or electrostrictive devices with electrical input and mechanical output, e.g. functioning as actuators or vibrators using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders
    • H10N30/2041—Beam type
    • H10N30/2042—Cantilevers, i.e. having one fixed end
    • H10N30/2043—Cantilevers, i.e. having one fixed end connected at their free ends, e.g. parallelogram type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2203/00—Basic microelectromechanical structures
    • B81B2203/01—Suspended structures, i.e. structures allowing a movement
    • B81B2203/0118—Cantilevers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2201/00—Details of transducers, loudspeakers or microphones covered by H04R1/00 but not provided for in any of its subgroups
    • H04R2201/003—Mems transducers or their use

Definitions

  • the present invention relates generally to miniature-sized sound generators. Especially, the invention relates to a micro-electro- mechanical-system (MEMS) based sound producing device according to the preamble of claim 1.
  • MEMS micro-electro- mechanical-system
  • the vibration amplitude is a limiting factor for producing sound pressure from small membrane speakers. This is especially the case at lower frequencies. In general, a larger diaphragm diameter enables a given sound-pressure-level (SPL) at a smaller deflection amplitude. Conversely, an increased vibration amplitude thus allows for smaller speakers at the same level of performance.
  • SPL sound-pressure-level
  • the diaphragm of a speaker for example in the form of a MEMS based sound producing device typically includes two or more separate elements, e.g. cantilevers that are mechanically connected to respective piezoelectric actuators.
  • the gaps between the cantilevers become relatively large, which causes acoustic leakage that reduce the efficiency.
  • the acoustic leakage may be avoided by the strategy for obtaining high sound-pressure-level MEMS speakers via a rigid-flexible vibration coupling mechanism of unsealed piezoelectric cantilevers and a sealed Parylene C membrane described in the article Wang, Q., et al., Obtaining High SPL Piezoelectric MEMS Speaker via a Rigid-flexible Vibration Coupling Mechanism, Journal of Microelectromechanical Systems, Volume 30, No. 5, 2021 , DOI: 10.1 109/ JMEMS.2021 .3087718.
  • the speaker comprises six identical triangular vibration cantilevers elements arranged to form a regular hexagonal vibration membrane with a side length of 2 mm.
  • the speaker has a PZT thin film layer and Pt layers as upper and lower electrodes; its elastic actuator layer is a SiO2/Si/ SiO2/Si multilayer composite film, and its substrate is an SOI one.
  • Parylene C is deposited on the vibration cantilever surfaces and the sidewalls and bottoms of the etched gaps before etching the back cavity.
  • the SPL produced by the speaker with the rigid-flexible-coupling sealed vibration membrane increased by 3 - 12.2 dB.
  • a sound producing device includes a base and at least one chip disposed on the base.
  • the chip includes at least one membrane and at least one actuator.
  • the membrane includes a coupling plate and at least one spring structure connected to the coupling plate.
  • the actuator is configured to receive a driving signal corresponding to an input audio signal to actuate the membrane, and the input audio signal and the driving signal have an input audio band which has an upper bound at a maximum frequency.
  • the spring structure is situated between the coupling plate and the actuator.
  • the membrane has a first resonance frequency higher than the maximum frequency.
  • WO 2018/035486 shows a piezoelectric, acoustic device compri- sing: a substrate; a plurality of plates, each plate comprising a first electrode layer, a piezoelectric layer and a second electrode layer, wherein the piezoelectric layer is in between the first electrode layer and the second electrode layer, and wherein, for each plate, a base of the plate is affixed to the substrate and a remaining portion of the plate is unaffixed to the substrate; and a plate coupling structure affixed to a first one of the plates and to a second one of the plates, wherein the plate coupling structure at least partly covers a gap between a first edge of the first one of the plates and a second edge of the second one of the plates, wherein the first edge faces the second edge; wherein the plate coupling structure comprises a mismatch reduction element and a stopping element, wherein the mismatch reduction element is configured to reduce an amount of mismatch in deflection of the first one of the plates and the second one of the plates
  • CN 209659620 II discloses a piezoelectric type MEMS microphone.
  • the piezoelectric loudspeaker comprises a substrate with a back cavity and a piezoelectric vibrating diaphragm arranged on the substrate, the piezoelectric vibrating diaphragm is divided into a plurality of independent diaphragms; each diaphragm comprises a fixed end connected with the substrate and a free end connected with the fixed end and suspended above the back cavity; the free end comprises two side edges formed along a parting line; wherein the two side edges of the same diaphragm are intersected, the side edges of two adjacent diaphragms are in contact with each other or are arranged at intervals, the piezoelectric MEMS microphone further comprises a buckle structure used for connecting the side edges of the two adjacent diaphragms, and the side edges of at least two diaphragms are connected through one or more buckle structures.
  • the piezoelectric MEMS microphone provided by the utility model has the advantages that the free end of the diaphragm is limited in the same plane through the arrangement of the buckle structure, the uniformity of product performance is improved, and the anti-falling performance is better.
  • the microphone includes a substrate having a back cavity and a piezoelectric cantilever diaphragm fixed to the substrate.
  • the piezoelectric cantilever diaphragm includes a plurality of diaphragm flaps, and each of the diaphragm flaps has one end fixed to the substrate and another end suspended above the back cavity. Every two adjacent ones of the diaphragm flaps are spaced apart to form a gap.
  • the piezoelectric microphone further comprises an elastically stretchable member connecting the two adjacent diaphragm flaps, and the elastically stretchable member is provided between at least one set of two adjacent ones of the diaphragm flaps.
  • the piezoelectric microphone of the present disclosure has better performance.
  • a piezoelectric microphone is a transducing device that is configured to convert sound into an electrical signal. Obviously, such a device is ill suited to produce sound based on an electrical signal. Namely, when designing a microphone accuracy is the most important parameter, i.e. that the induced diaphragm movements are as precise as possible in the sense that the diaphragms are influenced as little as possible by any other factors than the incoming sound waves. However, the magnitude of the diaphragm movements is essentially irrelevant. In a speaker/sound producing device essentially the opposite is true. Here, the magnitude of the induced movements is the most important parameter, whereas the accuracy of these movements is less critical.
  • the coupling plate introduces inertia in the system, which, in turn, leads to energy losses.
  • the object of the present invention is therefore to offer an en- ergy-eff icient MEMS based sound producing device that allows a high total membrane deflection while mitigating the above problems.
  • a MEMS- based sound producing device including a support structure, at least three flexible cantilevers and a set of links.
  • the support structure surrounds a cavity, and each of the at least three flexible cantilevers has a respective base side along which the flexible cantilever is attached to the support structure.
  • Each of the flexible cantilevers further has side edges that are movable relative to the support structure.
  • the flexible cantilevers are arranged over the cavity, such that each of them adjoins two neighboring flexible cantilevers along respective side edges and the flexible cantilevers together cover the cavity.
  • Each of the flexible cantilevers is configured to be deflected relative to the support structure in response to a control signal influencing a respective piezoelectric actuator that is mechanically linked to each of the flexible cantilevers.
  • the piezoelectric actuator may cover either a part of or the entire upper and/or lower surface of the flexible cantilever to which it is mechanically linked.
  • the links in the set of links are arranged between the flexible cantilevers such that exclusively the side edges of two neighboring flexible cantilevers of said flexible cantilevers are mechanically coupled to one another. Specifically, each of the flexible cantilevers is connected to two other ones of the flexible cantilevers via the links.
  • the above MEMS-based sound producing device is advantageous because it avoids the central coupling plate and enables larger displacements between the cantilevers while keeping their movements synchronized to one another.
  • At least a subset of the links in the set of links are constituted by respective unbroken sections of said flexible cantilevers between the respective flexible cantilevers being mechanically coupled to one another.
  • the slits between different flexible cantilevers may not continue all the way to the support structure such that two or more flexible cantilevers share a common base side.
  • the flexible cantilevers become relatively firmly interconnected, especially if an extension of the unbroken section is large compared to a length of the slit between the flexible cantilevers.
  • each of the links between the flexible cantilevers includes a respective spring structure, which, in turn, is formed by one or more cut-outs in at least one of the flexible cantilevers between which the link is arranged.
  • a spring structure design is advantageous because it is uncomplicated to implement. It is also straightforward to adjust the spring constant of the link by varying the number of cutouts and/or the respective lengths of the cut-outs.
  • one or more of the cut-outs contains a stress-relief cut-out section at a terminating end to reduce the risk of mechanical damages in this region.
  • respective side edges of the flexible cantilevers form an opening between themselves, which opening is located in an area over the cavity.
  • Such an opening is beneficial because it allows comparatively large cantilever deflections. To keep the acoustic leakage moderate, however, the opening should be relatively small.
  • said opening should be positioned centrally over the cavity.
  • the cavity has a general polygonal outline in a plane covered by the cantilevers.
  • the cavity may for example have a regular outline in the form of a triangle, a square or a hexagon. This is generally advantageous for manufacturing reasons and considering acoustic performance.
  • each of the cantilevers has such an outline that its width parallel to the base side generally tapers off from the base side towards an edge point on the respective cantilever, which edge point is furthest away from the base side.
  • the cantilever outline may be triangular. Such a cantilever outline is advantageous, since it harmonizes with the general polygonal outline of the cavity in a straightforward manner.
  • each of the cantilevers instead has such an outline that its width parallel to the base side is wider than the base side at least at one position between the base side and an edge point of the cantilever, which edge point is furthest away from the base side.
  • This type of cantilever outline is advantageous because it allows for comparatively large energy exchange between the cantilevers and the surrounding air.
  • the ME MS- based sound producing device further contains a flexible polymer membrane that covers the flexible cantilevers and a portion of the support structure adjoining the respective base sides of the flexible cantilevers.
  • a flexible polymer membrane that covers the flexible cantilevers and a portion of the support structure adjoining the respective base sides of the flexible cantilevers.
  • the flexible polymer membrane is elastic and the flexible polymer membrane is arranged over the flexible cantilevers and the support structure to stretch in response to deflecting the flexible cantilevers relative to the support structure.
  • the flexible polymer membrane is arranged such that in a first positioning of the flexible cantilevers in response to at least one first signal value of the control signal, the flexible polymer membrane is folded to form at least one fold between at least two of said flexible cantilevers. In a second positioning of the flexible cantilevers in response to at least one second signal value of the control signal, the at least one fold is unfolded due to a deflection of the flexible cantilevers relative to the support structure.
  • the flexible polymer membrane may be arranged to attain a good overall energy efficiency with respect to acoustic leakages and mechanical losses due to the interaction between the flexible cantilevers and the flexible polymer membrane.
  • respective side edges of each of the flexible cantilevers form an opening between themselves, which opening is located in an area over the cavity, where the flexible polymer membrane covers the opening, and the opening may or may not be positioned centrally over the cavity.
  • Figures 1 a-b show top and side cross-section views respectively of a MEMS-based sound producing device according to one embodiment of the invention
  • Figures 2-3 show top views of a MEMS-based sound producing device according to embodiments of the invention.
  • Figures 4a-e exemplify designs of spring structures mechanically interconnecting two neighboring flexible cantilevers according to different embodiments of the invention
  • FIGS 5-7 show top views of a MEMS-based sound produ- cing device according to embodiments of the in vention
  • Figures 8a-b show side cross-section views of a MEMS-based sound producing device according to one embodiment of the invention, where a flexible polymer membrane covers the flexible cantilevers and a portion of the support structure;
  • Figures 9a-c show top and side cross-section views of a MEMS-based sound producing device according to one embodiment of the invention, where a flexible polymer membrane covers the flexible cantilevers, a portion of the support structure as well as a central opening formed between the flexible cantilevers;
  • FIGS. 10-13 show top views of a MEMS-based sound producing device according to embodiments of the invention, where the piezoelectric actuators cover the flexible cantilevers to various extent;
  • Figures 14a-b illustrate stress-relief cut-out sections according to embodiments of the invention.
  • Figure 1 a we see a top view of a MEMS-based sound producing device according to one embodiment of the invention.
  • Figure 1 b shows a side cross-section view of the MEMS-based sound producing device in Figure 1 a along AA.
  • the MEMS-based sound producing device contains a support structure S that surrounds a cavity V.
  • the cavity V has a general polygonal outline in a plane covered by the cantilevers.
  • the cavity V may for example have a square outline as illustrated in Figure 1 a, or a general triangular outline as illustrated in Figures 10 and 11 .
  • alternative outlines of the cavity V are likewise conceivable, such as hexagonal, octagonal or decagonal shapes.
  • the general polygonal outline of the cavity V has a regular shape.
  • the ME MS- based sound producing device further contains at least three flexible cantilevers and a set of links L1 , L2, L3 and L4 arranged between the flexible cantilevers, wherein each link couples one of the flexible cantilevers mechanically to another one of said flexible cantilevers.
  • the MEMS- based sound producing device has four flexible cantilevers of which two, C1 and C3 respectively, are visible in Figure 1 b.
  • Each of the flexible cantilevers has a respective base side b1 , b2, b3 and b4 along which the flexible cantilever is attached to the support structure S.
  • Each of the flexible cantilevers further has side edges e11 , e12; e21 , e22; e31 , e32 and e41 , e42 respectively that are movable relative to the support structure S.
  • the flexible cantilevers are arranged over the cavity V, such that each of the flexible cantilevers adjoins two neighboring flexible cantilevers along respective side edges and said flexible cantilevers together cover the cavity V. Moreover, each of the flexible cantilevers is configured to be deflected relative to the support structure S in response to a control signal influencing a respective piezoelectric actuator that is mechanically linked to each of the flexible cantilevers.
  • Figures 1 a and 1 b illustrate four such piezoelectric actuators in the form of A1 , A2, A3 and A4, which each is mechanically linked to one of the flexible cantilevers.
  • the links L1 , L2, L3 and L4 are arranged between the flexible cantilevers, wherein each link couples one of the flexible cantilevers mechanically to another one of the flexible cantilevers.
  • the links L1 , L2, L3 and L4 are arranged to exclusively couple the side edges e11 , e21 ; e22, e32; e31 , e41 and e42, e12 respectively of two neighboring flexible cantilevers mechanically to one another.
  • any given cantilever is only directly linked to the two cantilevers that have a respective side edge adjoining the cantilever in question, and not directly linked to the cantilever being directly opposite to the cantilever in question.
  • each of the flexible cantilevers is connected to exactly two other flexible cantilevers via the links L1 , L2, L3 and L4.
  • Figure 1 b illustrates how the cantilevers C1 and C3, in response to the control signal to piezoelectric actuators A1 and A3 being mechanically linked to the cantilevers C1 and C3 respectively, may be deflected up and down relative to the support structure S above the cavity V, for example to produce sound.
  • the piezoelectric actuators A1 and A3 are arranged on a top side of the cantilevers C1 and C3.
  • the piezoelectric actuators A1 and A3 may equally well be arranged on a bottom side of the cantilevers C1 and C3, or on both the top and bottom sides thereof.
  • the piezoelectric actuators A1 and A3 cover the entire top side surface of the cantilevers C1 and C3. As will be discussed below with reference to Figures 11 , 12 and 13, according to other embodiments of the invention, the piezoelectric actuators may cover only a portion of the respective cantilever surface.
  • each of the cantilevers has such an outline that its width parallel to the base side b1 , b2, b3 and b4 respectively generally tapers off from the base side b1 , b2, b3 and b4 towards an edge point ep1 , ep2, ep3 and ep4 on the respective cantilever, which edge point ep1 , ep2, ep3 and ep4 is furthest away from the base side b1 , b2, b3 and b4 respectively.
  • This means that the cantilevers may have triangular outlines.
  • Figure 2 shows a top view of a MEMS-based sound producing device according to one embodiment of the invention.
  • all reference signs that also occur in Figures 1 a and/or 1 b designate the same parts/components as described above with reference to these figures.
  • the links between the flexible cantilevers are constituted by respective unbroken sections L12, L22, L32 and L42 of the flexible cantilevers, which unbroken sections L12, L22, L32 and L42 are located between the respective flexible cantilevers that are mechanically coupled to one another.
  • This design results in that the flexible cantilevers are relatively firmly linked to one another.
  • the flexible cantilevers will be deflected in a highly synchronized manner in response to the control signal to the piezoelectric actuators A1 , A2, A3 and A4 respectively that are mechanically linked to the flexible cantilevers.
  • only a subset of the links in the set of links may be constituted by the unbroken sections L12, L22, L32 and/or L42.
  • the remaining links in the set of links may be constituted by one or more other types of links, for example as exemplified below with reference to Figures 3 and 4a to 4e.
  • each of the flexible cantilevers is connected to exactly two other flexible cantilevers via the links L12, L22, L32 and L42.
  • Figure 2 also shows an opening OP, which is located in an area Y over the cavity V and which opening OP is formed between the side edges e11 , e21 ; e22, e32; e31 , e41 and e42, e12 respectively of the flexible cantilevers.
  • the opening OP is here positioned centrally over the cavity V.
  • Such an opening OP is advantageous because it leaves room for additional optimizing of the MEMS based sound producing device. Further, the opening OP enables comparatively large deflections of the flexible cantilevers over the cavity V.
  • FIG 3 shows a top view of a MEMS-based sound producing device according to one embodiment of the invention.
  • all reference signs that also occur in Figures 1 a, 1 b and/or Figure 2 designate the same parts/components as described above with reference to these figures.
  • each of said links L1 , L2, L3 and L4 that couples the flexible cantilevers mechanically to another one includes a respective spring structure, which is formed by one or more cut-outs in at least one of the flexible cantilevers between which the link is arranged. More precisely, each of the flexible cantilevers is connected to exactly two other flexible cantilevers via the links L2, L2, L2 and L4 respectively.
  • Figures 4a, 4b, 4c, 4d and 4e exemplify different designs of links L forming such spring structures according to embodiments of the invention. Specifically, Figure 4a shows the spring-structure design of Figure 3 in somewhat further detail.
  • a first cut-out s1 is merely a rectilinear section between the two cantilevers.
  • a second cut-out s2 constitutes a continuation of the rectilinear section between the two cantilevers.
  • the second cut-out s2 bifurcates into first and second branches extending parallel to the first cut-out s1 , where the first branch extends on a first side of the first cut-out s1 and the second branch extends on a second side of the first cut-out s1.
  • the two cantilevers are thereby mechanically connected to one another via a spring structure formed in a zone where the first and second branches of the second cut-out s2 extend parallel to the first cut-out s1 .
  • a spring constant of the spring structure may be adjusted by varying a length of the zone where the first and second branches of the second cut-out s2 extend parallel to the first cut-out s1 , which zone is symbolized by F in Figure 4a.
  • Figure 4b shows a spring structure, where a first cut-out s3 in the form of a rectilinear section between the two cantilevers is terminated by an arrow-shaped cut-out, which meets a matching second cut-out s4 that also contains a continuation of rectilinear section between the two cantilevers.
  • the spring constant of the spring structure may be adjusted by varying the lengths F of the arrow-shaped portions of the first and second cut-outs s3 and s4.
  • Figure 4c shows a spring structure, where a first cut-out s5 in the form of a first rectilinear section between the two cantilevers is terminated by a first cut-out portion extending orthogonally to the first rectilinear section.
  • a second cut-out s6 contains a second cut-out portion extending parallel to the first cut-out portion and also contains a continuation of rectilinear section between the two cantilevers.
  • the spring constant of the spring structure may be adjusted by varying the lengths F of the first and second cut-out portions.
  • Figure 4d shows a spring structure, where a first cut-out s7 in the form of a first rectilinear section between the two cantilevers meets a second cut-out s8 in the form of a second rectilinear section between the two cantilevers such that there is an uncut area between the first and second cut-outs s7 and s9.
  • Third and fourth cut-outs s9 and s10 on each side of the uncut area extend parallel to the uncut area and respective end portions of the first and second cut-outs s7 and s8.
  • the spring constant of the spring structure may be adjusted by varying an extension F of the uncut area and the lengths of the third and fourth cut-outs s9 and s10.
  • Figure 4e shows a spring structure, where first and second rectilinear sections s11 and s12 respectively between the two cantilevers meet one another in a meander-shaped pattern.
  • the spring constant of the spring structure may be adjusted by varying different extensions F of the cut-outs forming the meandershaped pattern.
  • the spring structures described above further contain stress-relief cut-out sections. This namely reduces the risk of stress-related damages to the design.
  • Figures 14a and 14b illustrate examples of how such stress-relief cut-out sections may be implemented according to embodiments of the invention.
  • Figure 14a we see a variant of the spring-structure design of Figure 4a, where a first stress-relief cut-out section r1 in the form of a circular slot is arranged at a terminating end of the first cut-out s1 , and second and third stress-relief cut-out sections r21 and r22 respectively in the form of circular slots are arranged at the terminating ends of the first and second branches that extend parallel to the first cut-out s1.
  • the first stress-relief cut-out section r1 is also arranged at the terminating end of the first cut-out s1.
  • fourth and fifth stress-relief cut-out sections r23 and r24 respectively in the form of curved cut-outs are arranged at the terminating ends of the first and second branches that extend parallel to the first cut-out s1.
  • Figures 5, 6 and 7 show top views of a MEMS-based sound producing device according to embodiments of the invention.
  • all reference signs that also occur in Figures 1 a, 1 b 2, 3 and/or 4a to 4e designate the same parts/ components as described above with reference to these figures.
  • the links L1 , L2, L3 and L4 that couple the flexible cantilevers mechanically to one another include spring structures of the type illustrated in Figure 4b.
  • the links L1 , L2, L3 and L4 are of the same type as in Figure 5. However, in Figure 6, the links are arranged around the center of the cavity V. This means that all the arrow-matching second cut-outs s4 illustrated in Figure 4b meet in a common cross-shaped cut-out that includes the opening OP.
  • each of the flexi- ble cantilevers is connected to exactly two other flexible cantilevers via the links L1 , L2, L3 and L4 respectively.
  • each flexible cantilever is mechanically linked to two neighboring flexible cantilevers via respective pairs of links in the form of spring structures L1 ; L5, L2, L6; L3, L7 and L4, L8.
  • the mechanical interconnection between the flexible cantilevers may be varied substantially both with respect to the connection points and the spring constant.
  • Figures 8a and 8b show side cross-section views of a ME MS- based sound producing device according to one embodiment of the invention, where a flexible polymer membrane P covers the flexible cantilevers, here exemplified by C1 and C3.
  • a flexible polymer membrane P covers the flexible cantilevers, here exemplified by C1 and C3.
  • all reference signs that also occur in Figures 1 a, 1 b and/or 2 to 7 designate the same parts/components as described above with reference to these figures.
  • the flexible polymer membrane P also covers a portion of the support structure S that adjoins the respective base sides b1 , b2, b3 and b4 of the flexible cantilevers C1 and C3.
  • the flexible cantilevers C1 and C3 are in a second position in response to at least one second signal value of the control signal.
  • the flexible cantilevers C1 and C3 are deflected in relation to the support structure S such that the fold FD in the flexible polymer membrane P is unfolded.
  • the flexible polymer membrane P may be elastic.
  • Figure 9a shows a top view of a ME MS-based sound producing device according to one embodiment of the invention, where, analogous to the above, the flexible polymer membrane P covers the flexible cantilevers and a portion of the support structure S.
  • Figures 9b and 9c show side cross-section views of the MEMS-based sound producing device in Figure 9a along BB.
  • each of the flexible cantilevers has a respective side edge e13, e23, e33 and e43 that form the opening OP between themselves, where the opening OP is located in the area Y over the cavity V.
  • the opening OP is thus larger than a mere crossing of the cut-outs formed by the side edges e11 , e21 ; e22, e32; e31 , e41 and e42, e12 between the different flexible cantilevers in Figures 1 a and 2 to 7.
  • each of the flexible cantilevers is connected to exactly two other flexible cantilevers via the links L1 , L2, L3 and L4.
  • the flexible polymer membrane P covers the opening OP.
  • the opening OP is positioned centrally over the cavity V.
  • the flexible polymer membrane P may be elastic, such that it is stretched without forming a fold in any of a first or second positionings of the flexible cantilevers C1 and C3 in response to at least one first and second signal value of the control signal to the piezoelectric actuators A1 and A3 as illustrated in Figures 9b and 9c respectively.
  • the cavity V surrounded by the support structure S has a general triangular outline in the plane covered by the flexible cantilevers.
  • the cavity V is here covered by three symmetric flexible cantilevers, which each has such an outline that its width parallel to the base side b1 , b2 and b3 respectively is wider than the base side b1 , b2 and b3 at least at one position between the base side b1 , b2 and b3 and an edge point of the cantilever, which edge point is furthest away from the base side b1 , b2 and b3.
  • a flexible cantilever being mechanically linked to a piezoelectric actuator A2 has a base side b2 and side edges e21 , e22, e23 and e24, where the side edge e23 is furthest away from the base side b2, and the side edge e23 is also parallel to the base side b2. Together with corresponding edge sides of the other two flexible cantilevers, the side edge e23 also form the opening OP between themselves.
  • each of the flexible cantilevers is connected to exactly two other flexible cantilevers via the links L1 , L2 and L3 respectively.
  • the type of cantilever outline exemplified in Figure 10 is advantageous because it allows for comparatively large energy exchange between the cantilevers and the surrounding air.
  • Figures 11 , 12 and 13 show top views of a MEMS-based sound producing device according to embodiments of the invention, where, unlike the embodiments discussed so far, piezoelectric actuators A1 , A2 and A3 and A1 , A2, A3 and A4 respectively cover less than an entire top surface of the flexible cantilevers, in Figures 1 1 , 12 and 13 all reference signs that also occur in the figures discussed above designate the same parts/compo- nents as described above with reference to these figures
  • each piezoelectric actuator A1 , A2 and A3 covers a respective top-surface area of the flexible cantilevers C1 , C2 and C3 between the base side b1 , b2 and b3 and a line parallel thereto where the flexible cantilever is widest.
  • any other partial coverage of the flexible cantilever by the piezoelectric actuator is conceivable. A couple of such additional examples are shown in Figures 12 and 13 respectively.
  • Figure 12 shows an embodiment of the invention corresponding to Figure 1 a, however where the piezoelectric actuators A1 , A2, A3 and A4 only cover a mid-portion of the flexible cantilevers C1 , C2, C3 and C4 respectively.
  • Figure 13 shows an embodiment of the invention corresponding to Figure 2, however where the piezoelectric actuators A1 , A2, A3 and A4 only cover the outer portions of the flexible cantilevers C1 , C2, C3 and C4 respectively, which outer portions adjoin the base sides b1 , b2, b3 and b4 respectively.
  • each of the flexible cantilevers is connected to exactly two other flexible cantilevers via the links L1 , L2, L3 and L4.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Manufacturing & Machinery (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Mechanical Engineering (AREA)
  • Multimedia (AREA)
  • Micromachines (AREA)
  • Piezo-Electric Transducers For Audible Bands (AREA)

Abstract

L'invention concerne un dispositif de production de son à base de MEMS comprenant une structure de support (S) qui entoure une cavité. Au moins trois porte-à-faux flexibles sont fixés à la structure de support (S) le long d'un côté de base respectif (b1, b2, b3, b4). Chaque porte-à-faux comporte des bords latéraux (e11, e12; e21, e22; e31, e32; e41, e42) qui sont mobiles par rapport à la structure de support (S). Les porte-à-faux flexibles sont disposés sur la cavité de telle sorte que chacun d'eux est adjacent à deux porte-à-faux flexibles voisins le long de bords latéraux respectifs. Les porte-à-faux flexibles couvrent ensemble la cavité et chacun d'entre eux est configuré pour être défléchi par rapport à la structure de support (S) en réponse à un signal de commande influençant un actionneur piézoélectrique respectif (A1, A2, A3, A4) lié mécaniquement au porte-à-faux flexible. Un ensemble de liens (L1, L2, L3, L4) est disposé entre les cantilevers flexibles, de sorte que les liens (L1, L2, L3, L4) couplent exclusivement les bords latéraux (e11, e21 ; e22, e32 ; e31, e41 ; e42, e12) de deux cantilevers flexibles voisins mécaniquement l'un à l'autre.
PCT/EP2024/080946 2023-11-06 2024-11-01 Dispositif de production de son basé sur un système micro-électromécanique Pending WO2025098889A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE2351266-8 2023-11-06
SE2351266A SE546765C2 (en) 2023-11-06 2023-11-06 A micro-electromechanical-system based sound producing device

Publications (1)

Publication Number Publication Date
WO2025098889A1 true WO2025098889A1 (fr) 2025-05-15

Family

ID=93379215

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2024/080946 Pending WO2025098889A1 (fr) 2023-11-06 2024-11-01 Dispositif de production de son basé sur un système micro-électromécanique

Country Status (2)

Country Link
SE (1) SE546765C2 (fr)
WO (1) WO2025098889A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20240363096A1 (en) * 2021-08-13 2024-10-31 Myvox Ab Sound generator, computer-implemented method for producing sound information, computer program and non-volatile data carrier

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018035486A1 (fr) 2016-08-18 2018-02-22 Vesper Technologies Inc. Structure de couplage de plaques
CN209659620U (zh) 2018-12-31 2019-11-19 瑞声声学科技(深圳)有限公司 压电式mems麦克风
US20200213770A1 (en) 2018-12-31 2020-07-02 Aac Acoustic Technologies (Shenzhen) Co., Ltd. Piezoelectric microphone
US20210024350A1 (en) * 2019-07-22 2021-01-28 Rosemount Aerospace Inc. Piezoelectric mems device with cantilever structures
US11057716B1 (en) 2019-12-27 2021-07-06 xMEMS Labs, Inc. Sound producing device
US20210297787A1 (en) * 2019-12-27 2021-09-23 xMEMS Labs, Inc. Package structure and methods of manufacturing sound producing chip, forming package structure and forming sound producing apparatus
US20220329951A1 (en) * 2020-01-28 2022-10-13 Murata Manufacturing Co., Ltd. Piezoelectric device

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT201900001017A1 (it) * 2019-01-23 2020-07-23 St Microelectronics Srl Trasduttore elettroacustico microelettromeccanico ad attuazione piezoelettrica e relativo procedimento di fabbricazione
US20230143656A1 (en) * 2021-11-09 2023-05-11 Qualcomm Technologies, Inc. Acoustic transducer with improved low-frequency response
US12382833B2 (en) * 2022-02-18 2025-08-05 Apple Inc. Piezoelectric mems valve for an electronic device
SE545977C2 (en) * 2022-12-22 2024-04-02 Myvox Ab A Micro-Electromechanical-System based Micro Speaker
CN117920557A (zh) * 2024-01-16 2024-04-26 天津大学 一种压电微机械超声换能器及电子设备

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018035486A1 (fr) 2016-08-18 2018-02-22 Vesper Technologies Inc. Structure de couplage de plaques
CN209659620U (zh) 2018-12-31 2019-11-19 瑞声声学科技(深圳)有限公司 压电式mems麦克风
US20200213770A1 (en) 2018-12-31 2020-07-02 Aac Acoustic Technologies (Shenzhen) Co., Ltd. Piezoelectric microphone
US20210024350A1 (en) * 2019-07-22 2021-01-28 Rosemount Aerospace Inc. Piezoelectric mems device with cantilever structures
US11057716B1 (en) 2019-12-27 2021-07-06 xMEMS Labs, Inc. Sound producing device
US20210297787A1 (en) * 2019-12-27 2021-09-23 xMEMS Labs, Inc. Package structure and methods of manufacturing sound producing chip, forming package structure and forming sound producing apparatus
US20220329951A1 (en) * 2020-01-28 2022-10-13 Murata Manufacturing Co., Ltd. Piezoelectric device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
WANG, Q. ET AL.: "Obtaining High SPL Piezoelectric MEMS Speaker via a Rigid-flexible Vibration Coupling Mechanism", JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, vol. 30, no. 5, 2021, XP011879081, DOI: 10.1109/JMEMS.2021.3087718

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20240363096A1 (en) * 2021-08-13 2024-10-31 Myvox Ab Sound generator, computer-implemented method for producing sound information, computer program and non-volatile data carrier

Also Published As

Publication number Publication date
SE2351266A1 (en) 2025-02-18
SE546765C2 (en) 2025-02-18

Similar Documents

Publication Publication Date Title
EP2103173B1 (fr) Microphone à détente de pression
US8045733B2 (en) Silicon microphone with enhanced impact proof structure using bonding wires
US7586241B2 (en) Electroacoustic transducer
CN103124389B (zh) 具有相互交叉的第一组梳齿和第二组梳齿的声换能器
KR102563920B1 (ko) 액추에이터로서의 벤딩 변환기, 센서로서의 벤딩 변환기, 벤딩 변환기 시스템
WO2025098889A1 (fr) Dispositif de production de son basé sur un système micro-électromécanique
JP7609780B2 (ja) 圧電素子
WO2021174571A1 (fr) Microphone mems piezoélectrique
CN114513729B (zh) 电子设备及声学换能器
US12192702B2 (en) MEMS speaker
CN116854022A (zh) 压电型微机电致动器装置和集成微机电致动器装置的设备
EP4639527A1 (fr) Haut-parleur miniature fondé sur un microsystème électromécanique
WO2024191333A1 (fr) Haut-parleur miniature fondé sur un microsystème électromécanique
CN118785061A (zh) Mems压电发声器及其制备方法
CN118785059A (zh) 一种耦合振膜的压电微机电扬声器
CN117041841A (zh) 电声变换器
EP4181534A1 (fr) Capteur acoustique directionnel
JP7660760B2 (ja) Ｍｅｍｓ素子
US20240147140A1 (en) Electroacoustic transducer, audio instrument, and wearable device
CN222547622U (zh) 压电mems发声单元及扬声器
US20250353733A1 (en) Electroacoustic transducer, array speaker, wearable device, speaker, ultrasonic transmitter, and method of manufacturing electroacoustic transducer
TWI884569B (zh) 壓電揚聲器及其製造方法
US12015898B2 (en) Transducer and driving method thereof, and system
CN223125012U (zh) 一种mems压电执行器及扬声器
CN218941328U (zh) 声换能装置及电子设备

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24801486

Country of ref document: EP

Kind code of ref document: A1