A thermal sounding device and an electronic device

A technology of thermally induced sound generation and electronic devices, which is applied in the directions of electrical components, sensors, sensor parts, etc., can solve the problems of low sound generation efficiency, etc., and achieve the effects of simple structure, low heat capacity, and cost reduction.

Active Publication Date: 2012-10-10
TSINGHUA UNIV +1
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Due to the limitation of the material itself, the thermoacoustic device using the platinum sheet as the...
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In the present embodiment, described composite film comprises the carbon nanotube drawing film and a Graphene film that two layers intersect each other, and this Graphene film comprises that two layers of Graphene overlaps each other and arranges, and the carbon that these two layers intersect each other The nanotube pulled film is arranged on the surface of the graphene film. Fig. 6 is a scanning electron micrograph of the composite film in this embodiment, the film cracked at the bottom is a graphene film, and the carbon nanotubes in the carbon nanotube drawn film are at the top. FIG. 7 is a graph showing the light transmittance test curve of the composite film in this embodiment. It can be seen from FIG. 7 that the light transmittance of the composite film provided in this embodiment can reach more than 60%. Therefore, when the composite film is used as the thermoacoustic element 102, a transparent sound-generating device can be obtained. The resistance of the composite film in this embodiment is 500 ohms, which has good electrical conductivity.
The thermal sound generating device 80 provided by the present embodiment is a double-sided sound generating device, by arranging the thermal sound generating element on two different surfaces, the sound propagation range of the thermal sound generating element can be made larger and more accurate. clear. By controlling the heating device, any one of the thermoacoustic elements can be selected to emit sound, or to emit sound at the same time, so that the application range of the thermoacoustic device is wider. Furthermore, when one thermoacoustic element breaks down, the other thermoacoustic element can continue to work, which improves the service life of the thermoacoustic device.
The thermoacoustic device 50 provided by the present embodiment adopts carbon nanotube composite structure as substrate 508, has the following advantages: the first, carbon nanotube composite structure comprises carbon nanotube layer and is coated on carbon nanotube layer surface The insulating material layer, because the carbon nanotube layer can be composed of pure carbon nanotube structure, therefore, the density of the carbon nanotube layer is small, the quality is relatively light, therefore, the thermoacoustic device 50 has a small mass, convenient Application; Second, the micropores in the carbon nanotube layer are formed by the gaps between the carbon nanotubes and are evenly distributed. In the case of a thin insulating material layer, the carbon nanotube composite structure can maintain the uniformly distributed micropores structure, therefore, the thermoacoustic element 102 can be in contact with the outside air more uniformly through the substrate 508; third, the carbon nanotube layer has good flexibility and can be bent many times without being damaged. Therefore, the carbon nanotube layer The nanotube composite structure has better flexibility, and the thermoacoustic device 50 using the carbon nanotube composite structure as the substrate 508 is a flexible sound emitting device, which can be set in any shape without limitation.
[0069] The thermoacoustic element 102 is disposed on the surface of the base 208, and is suspended relative to the through hole 208a on the base 208. In this embodiment, since the part of the thermoacoustic element 102 above the through hole 208a is suspended, both sides of the thermoacoustic element 102 in this part are in contact with the surrounding medium, which increases the contact between the thermoacoustic element 102 and the surrounding gas or liquid medium. Moreover, since another part of the thermoacoustic element 102 is in direct contact with the surface of the substrate 208 and is supported by the substrate 208, the thermoacoustic eleme...
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Abstract

A thermal sounding device comprises a substrate, a thermal sounding element arranged on the surface of the substrate, and a heating device used for providing energy to the thermal sounding element to enable the thermal sounding element to produce heat, wherein the thermal sounding element comprises a composite film, the composite film comprises at least a first carbon nano tube layer and at least one graphene film with the first carbon nano tube layer and the graphene film being stacked over each other, the substrate comprises a carbon nano tube composite structure, and the carbon nano tube composite structure comprises a second carbon nano tube layer and an insulation material layer coated on the surface of the second carbon nano tube layer. The invention further provides an electronic device using the thermal sounding device.

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  • A thermal sounding device and an electronic device
  • A thermal sounding device and an electronic device
  • A thermal sounding device and an electronic device

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Example Embodiment

[0034] Hereinafter, the thermal sound generating device provided by the embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, the same components are represented by the same reference numerals. The schematic diagrams involved in the embodiments of the present invention are for better description of the embodiments, and do not limit the embodiments themselves.
[0035] See figure 1 and figure 2 , The first embodiment of the present invention provides a thermo-sound device 10, the thermo-sound device 10 includes a thermo-sound element 102 and a uniform heating device 104.
[0036] The heating device 104 is used to provide energy to the thermosound element 102 so that the thermosound element 102 generates heat and emits sound. In this embodiment, the heating device 104 provides electric energy to the thermosound element, so that the thermosound element 102 generates heat under the action of Joule heat. The heating device 104 includes a first electrode 104a and a second electrode 104b. The first electrode 104a and the second electrode 104b are electrically connected with the thermosound element 102 respectively. In this embodiment, the first electrode 104 a and the second electrode 104 b are respectively disposed on the surface of the thermo-sound element 102 and are flush with two opposite sides of the thermo-sound element 102.
[0037] In this embodiment, the first electrode 104a and the second electrode 104b in the heating device 104 are used to provide electrical signals to the thermosound element 102, so that the thermosound element 102 generates Joule heat and the temperature rises, thereby emitting sound. The first electrode 104a and the second electrode 104b can be layered (filament or ribbon), rod-shaped, strip-shaped, block-shaped or other shapes, and the cross-sectional shape can be round, square, trapezoidal, or triangular. , Polygons or other irregular shapes. The first electrode 104a and the second electrode 104b can be fixed to the surface of the thermosound element 102 by means of adhesive bonding. In order to prevent the heat of the thermosound element 102 from being excessively absorbed by the first electrode 104a and the second electrode 104b and affect the sound effect, the contact area between the first electrode 104a and the second electrode 104b and the thermosound element 102 is small. Good, therefore, the shape of the first electrode 104a and the second electrode 104b is preferably a wire shape or a ribbon shape. The materials of the first electrode 104a and the second electrode 104b can be selected from metal, conductive glue, conductive paste, indium tin oxide (ITO), carbon nanotube or carbon fiber.
[0038] When the first electrode 104a and the second electrode 104b have a certain strength, the first electrode 104a and the second electrode 104b can play a role in supporting the thermosound element 102. For example, the two ends of the first electrode 104a and the second electrode 104b are respectively fixed on a frame, and the thermosound element 102 is arranged on the first electrode 104a and the second electrode 104b, and is suspended through the first electrode 104a and the second electrode 104b. Set up.
[0039] In this embodiment, the first electrode 104a and the second electrode 104b are wire-shaped silver electrodes formed on the thermosound element 102 by printing using silver paste, such as screen printing.
[0040] The thermosound device 10 further includes a first electrode lead (not shown) and a second electrode lead (not shown). The first electrode lead and the second electrode lead are respectively connected to the first electrode lead of the thermosound device 10 An electrode 104a and a second electrode 104b are electrically connected, the first electrode 104a is electrically connected with the first electrode lead, and the second electrode 104b is electrically connected with the second electrode lead. The thermo-sound device 10 is electrically connected to an external circuit through the first electrode lead 106a and the second electrode lead.
[0041] The thermosound element 102 includes a composite film including at least one carbon nanotube layer and at least one graphene film. The at least one carbon nanotube layer and the at least one graphene film are stacked on each other, that is, the at least one graphene film is disposed on the surface of the at least one carbon nanotube layer. The graphene film and the carbon nanotube layer can overlap each other, that is, when the area of ​​the graphene film is small, the graphene film is completely attached to the surface of the carbon nanotube layer; when the area of ​​the carbon nanotube layer is small, the carbon nanotube layer The layer can be completely attached to the surface of the graphene film. When the composite film includes a multilayer carbon nanotube layer and a multilayer graphene film, the multilayer carbon nanotube layer and the multilayer graphene film are alternately stacked. The thickness of the composite film is 10 nm to 1 mm. The length and width of the composite film are not limited, and can be cut according to the requirements of the thermosound device 10.
[0042] The graphene film is a two-dimensional structure with a certain area. The thickness of the graphene film is 0.34 nm to 10 nm. The graphene film includes at least one layer of graphene. When the graphene film includes multiple layers of graphene, the multiple layers of graphene may overlap each other to form a graphene film, so that the graphene film has a larger area; or the multiple layers of graphene may be superimposed on each other to form a graphene film, To increase the thickness of the graphene film. Preferably, the graphene film is a single-layer graphene. The graphene is a single-layer two-dimensional planar structure composed of a plurality of carbon atoms hybridized through sp2 bonds. The thickness of the graphene may be the thickness of a single layer of carbon atoms. Graphene film has high light transmittance, and the light transmittance of a single layer of graphene can reach 97.7%. Since the thickness of the graphene film is very thin, it has a low heat capacity, which can be less than 2×10 -3 Joule per square centimeter Kelvin, the heat capacity of a single layer of graphene can be less than 5.57×10 -4 Joules per square centimeter of Kelvin. The graphene film is a self-supporting structure. The self-supporting graphene film does not require a large-area carrier support, and as long as the opposite sides provide supporting forces, it can be suspended as a whole and maintain its own film-like state. When the film is placed on (or fixed on) two supports that are arranged at a fixed distance, the graphene film located between the two supports can be suspended to maintain its own film-like state. Experiments have shown that graphene is not a 100% smooth and flat two-dimensional film, but has a large number of microscopic fluctuations on the surface of the single-layer graphene. It is this way that the single-layer graphene maintains its self-supporting and self-supporting properties. stability.
[0043] The carbon nanotube layer includes a plurality of evenly distributed carbon nanotubes. The carbon nanotubes can be one or more of single-wall carbon nanotubes, double-wall carbon nanotubes, and multi-wall carbon nanotubes. The carbon nanotubes in the carbon nanotube layer can be tightly combined by van der Waals force. The carbon nanotube layer is a self-supporting structure. The carbon nanotubes in the carbon nanotube layer are disorderly or ordered. The disordered arrangement here means that the arrangement direction of the carbon nanotubes is irregular, and the ordered arrangement here means that the arrangement direction of at least most carbon nanotubes has a certain pattern. Specifically, when the carbon nanotube layer includes randomly arranged carbon nanotubes, the carbon nanotubes can be entangled with each other or arranged isotropically; when the carbon nanotube layer includes carbon nanotubes arranged in an orderly manner, the carbon nanotubes may be arranged along a line. Direction or multiple directions are arranged in a preferred orientation. The thickness of the carbon nanotube layer is not limited and may be 0.5 nanometers to 1 cm. Preferably, the thickness of the carbon nanotube layer may be 100 micrometers to 0.5 mm. The carbon nanotube layer further includes a plurality of micropores formed by gaps between the carbon nanotubes. The pore diameter of the micropores in the carbon nanotube layer may be less than or equal to 50 microns. The heat capacity per unit area of ​​the carbon nanotube layered structure is less than 2×10-4 Joules per square centimeter Kelvin. Preferably, the heat capacity per unit area of ​​the carbon nanotube layered structure may be less than or equal to 1.7×10-6 joules per square centimeter Kelvin. The carbon nanotube layer may include at least one layer of drawn carbon nanotube film, carbon nanotube flocculated film or carbon nanotube rolled film.
[0044] See image 3 The drawn carbon nanotube film includes a plurality of carbon nanotubes connected to each other by van der Waals forces. The plurality of carbon nanotubes are arranged in a preferential orientation substantially along the same direction. The preferred orientation means that the overall extension direction of most of the carbon nanotubes in the drawn carbon nanotube film is basically in the same direction. Moreover, the overall extension direction of most of the carbon nanotubes is substantially parallel to the surface of the drawn carbon nanotube film. Further, most of the carbon nanotubes in the drawn carbon nanotube film are connected end to end by van der Waals force. Specifically, each of the carbon nanotubes in most of the carbon nanotubes extending in the same direction in the drawn carbon nanotube film is connected end to end with the adjacent carbon nanotubes in the extending direction through van der Waals force. Of course, there are a few randomly arranged carbon nanotubes in the drawn carbon nanotube film, and these carbon nanotubes will not significantly affect the overall orientation arrangement of most of the carbon nanotubes in the drawn carbon nanotube film. The drawn carbon nanotube film is a self-supporting film. The self-supporting carbon nanotube stretched film does not require a large area of ​​carrier support, but as long as the opposite two sides provide supporting force, it can be suspended as a whole to maintain its own film state, that is, the carbon nanotube stretched film is placed (or fixed on) ) When two supports are arranged at a fixed distance, the drawn carbon nanotube film between the two supports can be suspended to maintain its own film state. The self-supporting is mainly realized by the presence of continuous carbon nanotubes in the drawn carbon nanotube film that are connected end to end by van der Waals force.
[0045] The thickness of the drawn carbon nanotube film may be 0.5 nanometers to 100 microns, and the width and length are not limited, and are set according to the size of the second substrate 108. For the specific structure and preparation method of the drawn carbon nanotube film, please refer to the patent application No. CN101239712A published on August 13, 2008 in Mainland China, which was filed by Fan Shoushan et al. on February 9, 2007. In order to save space, it is only cited here, but all the technical disclosures of the application should also be regarded as part of the technical disclosures of the present invention.
[0046] When the carbon nanotube layer includes a multi-layer drawn carbon nanotube film, the crossing angle formed between the extending directions of the carbon nanotubes in two adjacent drawn carbon nanotube films is not limited.
[0047] See Figure 4 The carbon nanotube flocculation film is a carbon nanotube film formed by a flocculation method. The carbon nanotube flocculating film includes carbon nanotubes entangled with each other and uniformly distributed. The carbon nanotubes are attracted to each other by van der Waals force and entangled to form a network structure. The carbon nanotube flocculation film is isotropic. The length and width of the carbon nanotube flocculating film are not limited. Since the carbon nanotubes are entangled with each other in the carbon nanotube flocculation film, the carbon nanotube flocculation film has good flexibility and is a self-supporting structure that can be bent and folded into any shape without breaking. The area and thickness of the carbon nanotube flocculation film are not limited, and the thickness is 1 micrometer to 1 millimeter. For the carbon nanotube flocculated film and its preparation method, please refer to Fan Shoushan et al.’s application on April 13, 2007 and published on October 15, 2008. Chinese Published Patent Application No. CN101284662A "Preparation of Carbon Nanotube Film" Method", applicant: Tsinghua University, Hongfujin Precision Industry (Shenzhen) Co., Ltd. In order to save space, it is only cited here, but all the technical disclosures of the above-mentioned applications should also be regarded as part of the technical disclosures of the present invention.
[0048] See Figure 5 The rolled carbon nanotube film includes evenly distributed carbon nanotubes, and the carbon nanotubes are arranged in preferred orientations in the same direction or in different directions. Carbon nanotubes can also be isotropic. The carbon nanotubes in the carbon nanotube rolled film partially overlap each other, and are attracted to each other through van der Waals force, and are tightly combined. The carbon nanotubes in the carbon nanotube rolled film and the surface of the growth substrate forming the carbon nanotube array form an included angle β, where β is greater than or equal to 0 degrees and less than or equal to 15 degrees (0≤β≤15°) . According to different rolling methods, the carbon nanotubes in the carbon nanotube rolling film have different arrangements. When rolled in the same direction, the carbon nanotubes are arranged in a preferred orientation along a fixed direction. It can be understood that when rolled in different directions, the carbon nanotubes can be arranged in preferred orientations in multiple directions. The thickness of the carbon nanotube rolled film is not limited, and is preferably 1 micrometer to 1 mm. The area of ​​the rolled carbon nanotube film is not limited, and is determined by the size of the carbon nanotube array rolled out of the film. When the size of the carbon nanotube array is larger, a larger area carbon nanotube rolled film can be produced by rolling. For the carbon nanotube rolled film and its preparation method, please refer to Fan Shoushan et al.’s application on June 1, 2007 and published on December 3, 2008, Chinese Patent Application No. CN101314464A "Preparation of Carbon Nanotube Film" Method", applicant: Tsinghua University, Hongfujin Precision Industry (Shenzhen) Co., Ltd. In order to save space, it is only cited here, but all the technical disclosures of the above-mentioned applications should also be regarded as part of the technical disclosures of the present invention.
[0049] In this embodiment, the composite film includes two layers of carbon nanotube drawn films intersecting each other and a graphene film. The graphene film includes two layers of graphene overlapping each other. The two layers of intersecting carbon nanotube drawn films The film is arranged on the surface of the graphene film. Image 6 This is a scanning electron micrograph of the composite film in this embodiment. The cracked film at the bottom is a graphene film, and the top is a carbon nanotube in the drawn carbon nanotube film. Figure 7 This is the light transmittance test curve diagram of the composite film in this embodiment. From Figure 7 It can be seen that the light transmittance of the composite film provided in this embodiment can reach more than 60%. Therefore, when the composite film is used as the thermosound element 102, a transparent sound emitting device can be obtained. The resistance of the composite film in this embodiment is 500 ohms, which has good conductivity.
[0050] The graphene film is a whole film, very dense, but the strength is poor; while the carbon nanotube layer has a certain strength, and there are a lot of voids, the composite film combines the graphene film to be more dense and the carbon nanotube layer has a larger Strength of strength. When the composite film is used as a sound element, the graphene film is placed on the carbon nanotube layer to cover the gaps in the carbon nanotube layer, so that the contact area between the composite film and the surrounding medium is larger than that of the carbon nanotube layer. The thermosound element can have higher sound efficiency; at the same time, when the composite film is used as the thermosound element, it has greater strength than the graphene film, which increases the intensity of the thermosound element and has a longer service life. The composite film also has the following advantages: firstly, the composite film has good willfulness and can be bent at any angle. Therefore, the thermo-sound device can be a flexible thermo-sound device; secondly, the graphene film and carbon nano The tube layer can have good light transmittance. Therefore, the composite film can also be a transparent film, and the thermosound device can be a transparent thermosound device; again, both the graphene film and the carbon nanotube layer have a small thickness Therefore, the thickness of the composite film can be thinner, the heat capacity can be smaller, and the temperature can be raised and lowered quickly. Therefore, the thermally induced sound device is more sensitive.
[0051] The preparation method of the graphene film may be a chemical vapor deposition method, an LB method, or a method of using tape from the oriented graphite. In this embodiment, the graphene film is prepared by the chemical vapor deposition method. The graphene film can be grown on the surface of a metal substrate by chemical vapor deposition, and the metal can be copper foil or nickel foil. Specifically, the preparation method of the graphene film includes the following steps:
[0052] First, a metal film substrate is provided.
[0053] The metal film can be copper foil or nickel foil. The size and shape of the metal film substrate are not limited, and can be adjusted according to the size and shape of the reaction chamber. The area of ​​the graphene film formed by the chemical vapor deposition method is related to the size of the metal thin film substrate, and the thickness of the metal thin film substrate may be 12.5 μm to 50 μm. In this embodiment, the metal film substrate is copper foil, a copper foil with a thickness of 12.5-50 microns, preferably 25 microns, and an area of ​​4 cm by 4 cm.
[0054] Secondly, the above-mentioned metal film substrate is put into the reaction chamber, and a carbon source gas is introduced at a high temperature to deposit carbon atoms on the surface of the metal film substrate to form graphene.
[0055] The reaction chamber is a quartz tube with a diameter of one inch. Specifically, the step of growing graphene in the reaction chamber includes the following steps: first annealing and reducing in a hydrogen atmosphere, the hydrogen flow rate is 2 sccm, the annealing temperature is 1000 degrees Celsius, and the time The carbon source gas methane is then introduced into the reaction chamber at a flow rate of 25 sccm to deposit carbon atoms on the surface of the metal film substrate. The pressure in the reaction chamber is 500 mtorr, and the growth time is 10 to 60 minutes, preferably 30 minute.
[0056] It can be understood that the flow rate of the gas introduced into the reaction chamber is related to the size of the reaction chamber, and those skilled in the art can adjust the flow rate of the gas according to the size of the reaction chamber.
[0057] Finally, cooling the metal film substrate to room temperature, thereby forming a layer of graphene on the surface of the metal film substrate.
[0058] During the cooling process of the metal film substrate, the carbon source gas and hydrogen gas should be continuously introduced into the reaction chamber until the metal film substrate is cooled to room temperature. In this embodiment, during the cooling process, 25 sccm of methane and 2 sccm of hydrogen are introduced into the reaction chamber, and cooled for 1 hour at a pressure of 500 mtorr to facilitate the removal of the metal thin film substrate. A layer of graphite is grown on the surface of the metal thin film substrate. Ene.
[0059] The carbon source gas is preferably a cheap gas acetylene, and other hydrocarbons such as methane, ethane, ethylene and the like can also be used. The protective gas is preferably argon, and other inert gases such as nitrogen can also be used. The deposition temperature of graphene is 800 degrees Celsius to 1000 degrees Celsius. The graphene of the present invention is prepared by a chemical vapor deposition method, so it can have a larger area, and the minimum size of the graphene film can be greater than 2 cm. Since the graphene film has a larger area, it can form a composite film with a larger area with the carbon nanotube layer.
[0060] After the graphene film is grown on the surface of the metal substrate by chemical vapor deposition, the carbon nanotube layer can be laid on the surface of the graphene film, and the carbon nanotube layer and the graphene film can be pressed together by mechanical force. Finally, the above-mentioned metal thin film substrate can be etched away with a solution to obtain a composite film composed of a graphene film and a carbon nanotube layer.
[0061] The graphene film prepared by the above method may be a single layer of graphene, or may include several layers of graphene. The number of graphene layers in the graphene film can be controlled by controlling the reaction temperature, base material and other conditions. In this embodiment, since the copper material of the copper foil substrate has a relatively low ability to dissolve carbon, the resulting graphene film only includes one graphene layer.
[0062] The working medium of the thermo-sound element 102 is not limited, as long as its resistivity is greater than that of the thermo-sound element 102. The medium includes a gaseous medium or a liquid medium. The gaseous medium may be air. The liquid medium includes one or more of non-electrolyte solutions, water, organic solvents, and the like. The resistivity of the liquid medium is greater than 0.01 ohm·m, and preferably, the liquid medium is pure water. The conductivity of pure water can reach 1.5×10 7 Ohm·meter, and its heat capacity per unit area is also large, which can conduct the heat generated by the thermo-sound element 102, so that the thermo-sound element 102 can dissipate heat. In this embodiment, the medium is air.
[0063] The thermo-sound device 10 of this embodiment can be electrically connected to an external circuit through the first electrode 104a and the second electrode 104b, and thus can be connected to an external signal to emit sound. Since the thermosound element 102 includes the composite film, the compound film has a smaller heat capacity per unit area and a larger heat dissipation area. After the heating device 104 inputs a signal to the thermosound element 102, the thermosound element 102 It can quickly rise and fall in temperature, produce periodic temperature changes, and quickly exchange heat with the surrounding medium, so that the density of the surrounding medium periodically changes, and then sounds. In short, the thermo-sounding element 102 of the embodiment of the present invention achieves sound generation through "electricity-thermo-acoustic" conversion. In addition, with the high light transmittance of the composite film, the thermo-sound device 10 is a transparent thermo-sound device.
[0064] The sound pressure level of the thermal sound generating device 10 provided in this embodiment is greater than 50 decibels per watt of sound pressure level, and the sound frequency range is 1 Hz to 100,000 Hz (ie, 1 Hz-100 kHz). The distortion degree of the thermally induced sound device in the frequency range of 500 Hz to 40,000 Hz may be less than 3%.
[0065] In addition, the composite film in this embodiment has good toughness and mechanical strength, so the graphene film can be conveniently made into a thermo-sound device 10 of various shapes and sizes, and the thermo-sound device 10 can be conveniently applied to Among various sound-producing devices, such as audio, mobile phones, MP3, MP4, TV, computers and other sound-producing devices.
[0066] See Figure 8 and Picture 9 , The second embodiment of the present invention provides a thermally induced sound generating device 20. The main difference between the thermosound device 20 provided in this embodiment and the thermosound device 10 provided in the first embodiment is that the thermosound device 20 in this embodiment further includes a base 208. The thermo-sound element 102 is disposed on the surface of the substrate 208. The first electrode 104a and the second electrode 104b are arranged on the surface of the thermosound element 102. The relationship between the thermosound element 102 and the substrate of this embodiment may be: first, the at least one carbon nanotube layer is disposed between the substrate 208 and the at least one graphene film; second, the at least one graphene film is disposed Between the substrate 208 and the at least one carbon nanotube layer; third, when the composite film includes multiple carbon nanotube layers and multiple graphene films alternately arranged with each other, the carbon nanotube layer directly contacts the substrate 208 or graphite The olefin film directly contacts the substrate 208. The carbon nanotube layer has the same structure as the carbon nanotube layer disclosed in the first embodiment. In this embodiment, the thermosound element 102 includes a layer of drawn carbon nanotube film and a layer of graphene, and the drawn carbon nanotube film is disposed between the graphene and the substrate 208. Since graphene itself is relatively dense, when the graphene is located on the drawn carbon nanotube film, the thermosound element 102 can have a larger contact area with the external medium.
[0067] The shape, size and thickness of the substrate 208 are not limited, and the surface of the substrate 208 can be flat or curved. The material of the substrate 208 is not limited, and may be a rigid material or a flexible material with a certain strength. Preferably, the electrical resistance of the material of the base 208 should be greater than the electrical resistance of the thermosound element 102, and it has better thermal insulation performance, so as to prevent the heat generated by the thermosound element 102 from being excessively absorbed by the substrate 208. Specifically, the insulating material may be glass, ceramic, quartz, diamond, plastic, resin or wood material.
[0068] In this embodiment, the substrate 208 includes at least one through hole 208a. The depth of the through hole 208 a is the thickness of the substrate 208. The shape of the cross section of the through hole 208a is not limited, and may be a circle, a square, a rectangle, a triangle, a polygon, an I-shape, or an irregular figure. When the substrate 208 includes a plurality of through holes 208a, the plurality of through holes 208a may be uniformly distributed, distributed regularly, or randomly distributed on the substrate 208. The distance between every two adjacent through holes 208a is not limited, and is preferably 100 μm to 3 mm. In this embodiment, the through holes 208a are cylindrical and are evenly distributed on the base 208.
[0069] The thermosound element 102 is arranged on the surface of the substrate 208 and is suspended relative to the through hole 208 a on the substrate 208. In this embodiment, since the part of the thermo-sound element 102 above the through hole 208a is suspended, both sides of the thermo-sound element 102 in this part are in contact with the surrounding medium, increasing the thermo-sound element 102 and the surrounding gas or liquid medium. The contact area, and since another part of the thermosound element 102 is in direct contact with the surface of the substrate 208 and is supported by the substrate 208, the thermosound element 102 is not easily damaged.
[0070] See Picture 10 , The third embodiment of the present invention provides a thermally induced sound generating device 30. The difference between the thermo-sound device 30 provided in this embodiment and the thermo-sound device 20 provided in the second embodiment is that, in this embodiment, the base 308 of the thermo-sound device 30 includes at least one blind groove 308a. The groove 308a is provided on one surface 308b of the base 308. The blind groove 308a forms an uneven surface on the surface 308b. The depth of the blind groove 308a is less than the thickness of the substrate 308, and the length of the blind groove 308a is not limited. The shape of the blind groove 308a on the surface 308b of the substrate 308 can be rectangular, arcuate, polygonal, oblate or other irregular shapes. See Picture 9 In this embodiment, the substrate 308 is provided with a plurality of blind grooves 308a, and the shape of the blind grooves 308a on the surface 308b of the substrate 308 is rectangular. See Picture 11 The cross section of the blind groove 308a in the longitudinal direction is rectangular, that is, the blind groove 308a has a rectangular parallelepiped structure. See Picture 12 The cross section of the blind groove 308a in the longitudinal direction is triangular, that is, the blind groove 308a has a triangular prism structure. When the surface 308b of the substrate 308 has a plurality of blind grooves, the plurality of blind grooves may be uniformly distributed, distributed regularly or randomly on the surface 308b of the substrate 308. See Picture 12 The gap between two adjacent blind grooves can be close to 0, that is, the contact area between the substrate 308 and the thermosound element 102 is multiple lines. It can be understood that, in other embodiments, by changing the shape of the blind groove 308a, the contact area between the thermosound element 102 and the substrate 308 is multiple points, that is, the area between the thermosound element 102 and the substrate 308 can be It is point contact, line contact or surface contact.
[0071] The base 308 in the thermosound device 30 of this embodiment includes at least one blind groove 308a. The blind groove can reflect the sound waves emitted by the thermosound element 102, thereby enhancing the sound intensity of the thermosound device 30 on the side of the thermosound element 102. When the distance between the adjacent blind grooves is close to 0, the base 308 can not only support the thermosound element 102, but also enable the thermosound element 102 to have the largest surface area in contact with the surrounding medium.
[0072] It can be understood that when the depth of the blind groove 308a reaches a certain value, the sound wave reflected by the blind groove 308a will be superimposed with the original sound wave, thereby causing destructive interference and affecting the sound effect of the thermosound element 102. To avoid this phenomenon, preferably, the depth of the blind groove 308a is less than or equal to 10 mm. In addition, when the depth of the blind groove 308a is too small, the distance between the thermal sound emitting element 102 suspended by the base 308 and the base 308 is too close, which is not conducive to the heat dissipation of the thermal sound emitting element 102. Therefore, preferably, the depth of the blind groove 308a is greater than or equal to 10 microns.
[0073] See Figure 13 and Figure 14 , The fourth embodiment of the present invention provides a thermally induced sound generating device 40. The difference between the thermosound device 40 provided in this embodiment and the thermosound device 20 provided in the second embodiment is that, in this embodiment, the base 408 of the thermosound device 40 is a mesh structure. The substrate 408 includes a plurality of first linear structures 408a and a plurality of second linear structures 408b. The linear structure may also be a strip or strip structure. The plurality of first linear structures 408a and the plurality of second linear structures 408b are arranged to cross each other to form a net-like structure base 408. The plurality of first linear structures 408a may or may not be parallel to each other, and the plurality of second linear structures 408b may or may not be parallel to each other. When the plurality of first linear structures 408a are parallel to each other And when the plurality of second linear structures 408b are parallel to each other, specifically, the axial directions of the plurality of first linear structures 408a all extend along the first direction L1, and the distance between adjacent first linear structures 408a It can be equal or unequal. The distance between two adjacent first linear structures 408a is not limited, and preferably, the distance is less than or equal to 1 cm. In this embodiment, the plurality of first linear structures 408a are arranged at equal intervals, and the distance between two adjacent first linear structures 408a is 2 cm. The plurality of second linear structures 408b are spaced apart from each other and their axial directions all extend substantially along the second direction L2, and the distance between adjacent second linear structures 408b may be equal or unequal. The distance between two adjacent second linear structures 408b is not limited, and preferably, the distance is less than or equal to 1 cm. The first direction L1 and the second direction L2 form an angle α, 0°
[0074] The base 408 has a plurality of meshes 408c. The plurality of meshes 408c are surrounded by the plurality of first linear structures 408a and the plurality of second linear structures 408b arranged to cross each other. The mesh 408c is quadrilateral. According to the angles at which the plurality of first linear structures 408a and the plurality of second linear structures 408b are intersected, the mesh 408c may be square, rectangular, or rhombus. The size of the mesh 408c is determined by the distance between two adjacent first linear structures 408a and the distance between two adjacent second linear structures 408b. In this embodiment, since the plurality of first linear structures 408a and the plurality of second linear structures 408b are arranged in parallel at equal intervals, and the plurality of first linear structures 408a and the plurality of second linear structures 408b are mutually It is vertical, so the mesh 408c is square with a side length of 2 cm.
[0075] The diameter of the first linear structure 408a is not limited, and is preferably 10 μm to 5 mm. The material of the first linear structure 408a is made of insulating material, and the material includes fiber, plastic, resin or silicone. The first linear structure 408a may be a textile material. Specifically, the first linear structure 408a may include one or more of plant fiber, animal fiber, wood fiber, and mineral fiber, such as cotton thread, twine, and wool. , Silk thread, nylon thread or spandex, etc. Preferably, the insulating material should have certain heat resistance and flexibility, such as nylon or polyester. In addition, the first linear structure 408a may also be a conductive wire covered with an insulating layer. The conductive wire can be a metal wire or a carbon nanotube-like structure. The metal includes an elemental metal or an alloy. The elemental metal can be aluminum, copper, tungsten, molybdenum, gold, titanium, neodymium, palladium, or cesium. The metal alloy can be an alloy of any combination of the aforementioned elemental metals. The material of the insulating layer can be resin, plastic, silicon dioxide, or metal oxide. In this embodiment, the first linear structure 408a is a carbon nanotube-like structure coated with silicon dioxide on the surface, and the insulating layer made of silicon dioxide wraps the carbon nanotube-like structure to form the first linear structure 408a.
[0076] The structure and material of the second linear structure 408b are the same as the structure and material of the first linear structure 408a. In the same embodiment, the structure and material of the second linear structure 408b may be the same as or different from the structure and material of the first linear structure 408a. In this embodiment, the second linear structure 408b is a carbon nanotube-like structure coated with an insulating layer on the surface.
[0077] The carbon nanotube-like structure includes at least one carbon nanotube, and the carbon nanotube includes a plurality of carbon nanotubes. The carbon nanotubes can be one or more of single-wall carbon nanotubes, double-wall carbon nanotubes, and multi-wall carbon nanotubes. The carbon nanotube wire may be a pure structure composed of a plurality of carbon nanotubes. When the carbon nanotube wire-like structure includes a plurality of carbon nanotube wires, the plurality of carbon nanotube wires may be arranged parallel to each other. When the carbon nanotube wire-like structure includes a plurality of carbon nanotube wires, the plurality of carbon nanotube wires may be spirally wound with each other. The multiple carbon nanotube wires in the carbon nanotube wire-like structure can also be fixed to each other by an adhesive.
[0078] The carbon nanotube wire may be a non-twisted carbon nanotube wire or a twisted carbon nanotube wire. See Figure 15 The non-twisted carbon nanotube wire includes a plurality of carbon nanotubes that extend along the length of the carbon nanotube wire and are connected end to end. Preferably, the non-twisted carbon nanotube wire includes a plurality of carbon nanotube segments connected end-to-end by van der Waals force, and each carbon nanotube segment includes a plurality of carbon nanotube segments that are parallel to each other and tightly coupled by van der Waals force. Of carbon nanotubes. The carbon nanotube segment has any length, thickness, uniformity and shape. The length of the non-twisted carbon nanotube wire is not limited, and the diameter is 0.5 nanometers to 100 micrometers.
[0079] The twisted carbon nanotube wire is obtained by using a mechanical force to twist the non-twisted carbon nanotube wire in the opposite direction. See Figure 16 The twisted carbon nanotube wire includes a plurality of carbon nanotubes arranged spirally around the axis of the carbon nanotube wire. Preferably, the twisted carbon nanotube wire includes a plurality of carbon nanotube segments connected end-to-end by van der Waals forces, and each carbon nanotube segment includes a plurality of parallel and tightly coupled van der Waals forces. Carbon nanotubes. The carbon nanotube segment has any length, thickness, uniformity and shape. The length of the twisted carbon nanotube wire is not limited, and the diameter is 0.5 nanometers to 100 micrometers. For the carbon nanotube wire and its preparation method, please refer to Fan Shoushan et al.’s application on September 16, 2002 and published on August 20, 2008, China Announcement Patent No. CN100411979C "A carbon nanotube rope and its manufacturing method" ", Applicant: Tsinghua University, Hongfujin Precision Industry (Shenzhen) Co., Ltd., and the Chinese public patent application No. CN1982209A published on June 20, 2007 "Carbon Nanotube Wire and Its Manufacturing Method", Applicant: Tsinghua University, Hongfujin Precision Industry (Shenzhen) Co., Ltd. In order to save space, it is only cited here, but all the technical disclosures of the above-mentioned applications should also be regarded as part of the technical disclosures of the present invention.
[0080] The thermo-sound device 40 provided by this embodiment adopts the net-like structure of the substrate 408, which has the following advantages: First, the net-like structure includes a plurality of meshes, which can provide support for the thermo-sound element 102 while simultaneously making the heat-induced sound The sound element 102 has a larger contact area with the surrounding medium. Second, the net-like structure of the substrate 408 can have better flexibility, and therefore, the thermosound device 40 has better flexibility. Third, when the first linear structure 408a or/and the second linear structure 408b include carbon nanotube wire-shaped structures coated with an insulating layer, the carbon nanotube wire-shaped structure may have a smaller diameter, which further increases the thermal conductivity. The contact area between the sound element 102 and the surrounding medium; the carbon nanotube-like structure has a smaller density, so the mass of the thermosound device 40 can be smaller; the carbon nanotube-like structure has better flexibility and can be bent multiple times It is folded without being damaged, and therefore, the thermal sound generating device 40 can have a longer service life.
[0081] See Figure 17 , The fifth embodiment of the present invention provides a thermally induced sound generating device 50. The difference between the thermosound device 50 provided in this embodiment and the thermosound device 20 provided in the second embodiment is that, in this embodiment, the base 508 of the thermosound device 50 is a carbon nanotube composite structure.
[0082] The carbon nanotube composite structure includes a carbon nanotube layer and an insulating material layer coated on the surface of the carbon nanotube layer. The structure of the carbon nanotube layer is the same as the structure of the carbon nanotube layer disclosed in the first embodiment. The insulating material layer is located on the surface of the carbon nanotube layer, and the function of the insulating material layer is to insulate the carbon nanotube layer and the thermosound element 102 from each other. The insulating material layer is only distributed on the surface of the carbon nanotube layer, or the insulating material layer wraps each carbon nanotube in the carbon nanotube layer. When the thickness of the insulating material layer is thin, the micropores in the carbon nanotube layer will not be blocked. Therefore, the carbon nanotube composite structure includes a plurality of micropores. The multiple micro-holes make the contact area between the thermo-sound element 102 and the outside world larger.
[0083] The thermosound device 50 provided in this embodiment uses a carbon nanotube composite structure as the base 508, and has the following advantages: First, the carbon nanotube composite structure includes a carbon nanotube layer and an insulating material coated on the surface of the carbon nanotube layer Since the carbon nanotube layer can be a structure composed of pure carbon nanotubes, the density of the carbon nanotube layer is small and the mass is relatively light. Therefore, the thermal sound generating device 50 has a small mass and is convenient for application; Second, the micropores in the carbon nanotube layer are formed by the gaps between the carbon nanotubes and are evenly distributed. When the insulating material layer is thin, the carbon nanotube composite structure can maintain the uniformly distributed micropore structure. , The thermo-sound element 102 can contact the outside air more uniformly through the substrate 508; third, the carbon nanotube layer has good flexibility and can be bent many times without being damaged. Therefore, the carbon nanotube composite The structure has good flexibility, and the thermosound device 50 using the carbon nanotube composite structure as the base 508 is a flexible sound device that can be set in any shape without limitation.
[0084] See Figure 18 and Figure 19 The sixth embodiment of the present invention provides a thermo-sound device 60. The thermo-sound device 60 includes a substrate 608, a heat-generating device 104 and a thermo-sound element 102. The heating device 104 includes a plurality of first electrodes 104a and a plurality of second electrodes 104b, and the plurality of first electrodes 104a and the plurality of second electrodes 104b are electrically connected to the thermosound element 102, respectively. The thermosound element 102 includes a graphene film.
[0085] The plurality of first electrodes 104a and the plurality of second electrodes 104b are alternately arranged on the substrate 608 at intervals. The thermosound element 102 is disposed on the plurality of first electrodes 104a and the plurality of second electrodes 104b, so that the plurality of first electrodes 104a and the plurality of second electrodes 104b are located between the substrate 608 and the thermosound element 102 Meanwhile, the thermo-sound element 102 is partially suspended relative to the base 608. That is, the plurality of first electrodes 104a, the plurality of second electrodes 104b, the thermosound element 102, and the substrate 608 jointly form a plurality of gaps 601, so that the thermosound element 102 has a larger contact area with the surrounding air. The distance between each adjacent first electrode 104a and second electrode 104b may be equal or unequal. Preferably, the distance between each adjacent first electrode 104a and second electrode 104b is equal. The distance between the adjacent first electrode 104a and the second electrode 104b is not limited, and is preferably 10 micrometers to 1 cm.
[0086] The substrate 608 mainly functions to support the first electrode 104a and the second electrode 104b. The shape and size of the base 608 are not limited, and the material is an insulating material or a material with poor conductivity. In addition, the material of the substrate 608 should have good thermal insulation performance, so as to prevent the heat generated by the thermosound element 102 from being absorbed by the substrate 608, and the purpose of heating the surrounding medium to generate sound cannot be achieved. In this embodiment, the material of the substrate 608 may be glass, resin or ceramics. In this embodiment, the substrate 608 is a square glass plate with a side length of 4.5 cm and a thickness of 1 mm.
[0087] The gap 601 is defined by a first electrode 104a, a second electrode 104b, and a substrate 608, and the height of the gap 601 depends on the height of the first electrode 104a and the second electrode 104b. In this embodiment, the height range of the first electrode 104a and the second electrode 104b is 1 micrometer to 1 cm. Preferably, the height of the first electrode 60a4 and the second electrode 104b is 15 microns.
[0088] The first electrode 104a and the second electrode 104b can be layered (filament or ribbon), rod-shaped, strip-shaped, block-shaped or other shapes, and the cross-sectional shape can be round, square, trapezoidal, or triangular. , Polygons or other irregular shapes. The first electrode 104a and the second electrode 104b can be fixed to the base 608 by means of bolt connection or adhesive bonding. In order to prevent the heat of the thermosound element 102 from being excessively absorbed by the first electrode 104a and the second electrode 104b and affect the sound effect, the contact area between the first electrode 104a and the second electrode 104b and the thermosound element 102 is small. Good, therefore, the shape of the first electrode 104a and the second electrode 104b is preferably a wire shape or a ribbon shape. The materials of the first electrode 104a and the second electrode 104b can be selected from metals, conductive glue, conductive paste, indium tin oxide (ITO), carbon nanotubes, or carbon fibers. When the material of the first electrode 104a or the second electrode 104b is carbon nanotubes, the first electrode 104a or the second electrode 104b may be a carbon nanotube-like structure. The structure of the carbon nanotube wire-like structure is the same as the carbon nanotube wire-like structure provided in the fourth embodiment. Because the carbon nanotubes in the carbon nanotube-like structure are connected end to end, the carbon nanotube-like structure has good conductivity and can be used as an electrode.
[0089] The sounding device 60 further includes a first electrode lead 610 and a second electrode lead 612. The first electrode lead 610 and the second electrode lead 612 are respectively connected to the first electrode 104a and the second electrode 104b of the thermo-sounding device 60. The connection is such that the plurality of first electrodes 104a are electrically connected to the first electrode lead 610, and the plurality of second electrodes 104b are electrically connected to the second electrode lead 612, respectively. The sound generating device 60 is electrically connected to an external circuit through the first electrode lead 610 and the second electrode lead 612. This connection method can greatly reduce the sheet resistance of the thermosound element 102 between the first electrode lead 610 and the second electrode lead 612, and can improve the sound efficiency of the thermosound element 102.
[0090] In this embodiment, the plurality of first electrodes 104a and the plurality of second electrodes 104b can support the thermosound element 102, and therefore, the substrate 608 is not an essential element. When the thermosound device 60 in this embodiment does not include the substrate 608, the first electrode 104a and the second electrode 104b can protect and support the thermosound element while electrically connecting the thermosound element 102 to an external circuit. 102.
[0091] In this embodiment, the first electrode 104a and the second electrode 104b are wire-shaped silver electrodes formed by a screen printing method. The number of the first electrodes 104 a is four, and the number of the second electrodes 104 b is four. The four first electrodes 104 a and the four second electrodes 104 b are alternately and equally spaced on the substrate 608. Each of the first electrode 104a and the second electrode 104b has a length of 3 cm and a height of 15 microns, and the distance between the adjacent first electrode 104a and the second electrode 104b is 5 mm.
[0092] In the thermosound device 60 provided in this embodiment, the thermosound element 102 is suspended by a plurality of first electrodes 104a and a plurality of second electrodes 104b, which increases the contact area between the thermosound element 102 and the surrounding air, which is beneficial to The thermally induced sound element 102 exchanges heat with the surrounding air, which improves the sound efficiency.
[0093] See Picture 20 with Figure 21 , The seventh embodiment of the present invention provides a thermally induced sound generating device 70. The thermo-sound device 70 includes a substrate 608, a heat-generating device 104 and a thermo-sound element 102. The heating device 104 includes a plurality of first electrodes 104a and a plurality of second electrodes 104b, and the plurality of first electrodes 104a and a plurality of second electrodes 104b are electrically connected to the thermosound element 102, respectively. The thermosound element 102 includes a graphene film. The structure of the thermosound device 70 provided in this embodiment is basically the same as that of the thermosound device 60 provided in the sixth embodiment. The difference is that in this embodiment, two adjacent first electrodes 104a and second At least one spacer 714 is further included between the electrodes 104b.
[0094] The spacer element 714 and the base 608 may be separate elements, and the spacer element 714 is fixed to the base 608 by means such as bolt connection or adhesive bonding. In addition, the spacer element 714 can also be integrally formed with the base 608, that is, the material of the spacer element 714 is the same as the material of the base 608. The shape of the spacer 714 is not limited, and can be a spherical, filamentary or ribbon-like structure. In order to keep the thermo-sound element 102 having a good sound effect, the spacer element 714 should have a small contact area with the thermo-sound element 102 while supporting the thermo-sound element 102. Preferably, the spacer element 714 and the thermo-sound element 102 The elements 102 are in point contact or line contact.
[0095] In this embodiment, the material of the spacer 714 is not limited, and it can be an insulating material such as glass, ceramic, or resin, or a conductive material such as metal, alloy, or indium tin oxide. When the spacing element 714 is a conductive material, it is electrically insulated from the first electrode 104a and the second electrode 104b, and, preferably, the spacing element 714 is parallel to the first electrode 104a and the second electrode 104b. The height of the spacer 714 is not limited, and is preferably 10 micrometers to 1 cm. In this embodiment, the spacer element 714 is silk-like silver formed by a screen printing method, and the height of the spacer element 714 is the same as the height of the first electrode 104a and the second electrode 104b, which is 20 microns. The spacer 714 is arranged in parallel with the first electrode 104a and the second electrode 104b. Since the height of the spacer element 714 is the same as the height of the first electrode 104a and the second electrode 104b, the thermosound element 102 is located on the same plane.
[0096] The thermosound element 102 is disposed on the spacer element 714, the first electrode 104a and the second electrode 104b. The thermosound element 102 is spaced from the substrate 608 through the spacer element 714, and forms a space 701 with the substrate 608. The space 701 is defined by the first electrode 104a or the second electrode 104b and the spacer element 714, the substrate 608, and the thermo-sound element 102 are formed together. Furthermore, in order to prevent the thermosound element 102 from generating standing waves and maintain the sound effect of the thermosound element 102, the distance between the thermosound element 102 and the substrate 608 is preferably 10 micrometers to 1 cm. In this embodiment, since the height of the first electrode 104a, the second electrode 104b, and the spacer element 714 is 20 microns, the thermosound element 102 is disposed on the first electrode 104a, the second electrode 104b, and the spacer element 714. Therefore, The distance between the thermo-sound element 102 and the substrate 608 is 20 microns.
[0097] It can be understood that the first electrode 104a and the second electrode 104b also have a certain supporting effect on the thermosound element 102, but when the distance between the first electrode 104a and the second electrode 104b is large, The supporting effect is not good. The spacer 714 is arranged between the first electrode 104a and the second electrode 104b, which can better support the thermo-sound element 102, so that the thermo-sound element 102 and the substrate 608 are spaced apart from the substrate. A space 701 is formed in 608, so as to ensure that the thermo-sound element 102 has a good sound effect.
[0098] See Figure 22 , The eighth embodiment of the present invention provides a thermally induced sound generating device 80. The thermosound device 80 includes at least one heating device and a plurality of thermosound elements. There are two situations for the plurality of thermosound elements: first, the number of the plurality of thermosound elements is at least two, and there is no mutual contact between the thermosound elements; second, the plurality of thermosound elements The number of the element is one, and the thermosound element is arranged on a curved substrate with multiple normal directions or the thermosound element is bent and arranged on different planes. The heating device can have a one-to-one correspondence with the thermo-sound elements, or one heating device can correspond to multiple thermo-sound elements. The heating device may also be an integral structure composed of a plurality of parts corresponding to the plurality of thermosound elements. In this embodiment, the thermosound device 80 includes a first heating device 804, a second heating device 806, a substrate 208, a first thermosound element 802a, and a second thermosound element 802b.
[0099] The substrate 208 includes a first surface 808a and a second surface 808b. The shape, size and thickness of the substrate 208 are not limited. The first surface 808a and the second surface 808b may be flat, curved, or uneven surfaces. The first surface 808a and the second surface 808b may be two adjacent surfaces, or may be two opposite surfaces. In this embodiment, the substrate 208 has a rectangular parallelepiped structure, and the first surface 808a and the second surface 808b are two opposite surfaces. The substrate 208 further includes a plurality of through holes 810 which penetrate through the first surface 808a and the second surface 808b, so that the first surface 808a and the second surface 808b become uneven surfaces. The plurality of through holes 208a may be arranged parallel to each other.
[0100] The first thermosound element 802a is disposed on the first surface 808a of the substrate 208, and is at least partially suspended relative to the first surface 808a. The second thermosound element 802b is disposed on the second surface 808b, and is at least partially suspended relative to the second surface 808b. The first thermosound element 802a is a composite film, and the composite film has the same properties as the composite film disclosed in the first embodiment. The second thermosound element 802b is a graphene film, a carbon nanotube layer or the composite film. The structure of the carbon nanotube layer is the same as the structure of the carbon nanotube layer disclosed in the first embodiment.
[0101] The first heating device 804 includes a first electrode 104a and a second electrode 104b. The first electrode 104a and the second electrode 104b are respectively electrically connected with the first thermosound element 802a. In this embodiment, the first electrode 104a and the second electrode 104b are respectively disposed on the surface of the first thermosound element 802a, and are flush with two opposite sides of the first thermosound element 802a. The second heating device 806 includes a first electrode 104a and a second electrode 104b. The first electrode 104a and the second electrode 104b are electrically connected to the second thermosound element 802b, respectively. In this embodiment, the first electrode 104a and the second electrode 104b are respectively arranged on the surface of the second thermosound element 802b and are flush with two opposite sides of the first thermosound element 802a.
[0102] The thermo-sound device 80 provided in this embodiment is a double-sided sound-producing device. By arranging thermo-sound elements on two different surfaces, the sound transmission range from the thermo-sound elements can be made larger and clearer. By controlling the heating device, it is possible to select any one of the thermo-sound components to emit sound, or to emit sound at the same time, so that the use range of the thermo-sound device is wider. Further, when one thermo-sound element fails, the other thermo-sound element can continue to work, which improves the service life of the thermo-sound device.
[0103] See Figure 23 , The ninth embodiment of the present invention provides a thermally induced sound generating device 90. The thermo-sound device 90 includes a base 908, a plurality of thermo-sound elements 102 and a plurality of heating devices 104. The base 908 includes a plurality of surfaces 908a, and each thermosound element 102 is correspondingly disposed on one surface 908a, and the thermosound element 102 and the heating device 104 are in a one-to-one correspondence. The structure of the thermo-sound device 90 provided in this embodiment is basically the same as that of the thermo-sound device 80 provided in the eighth embodiment. The difference is that the thermo-sound device 90 provided in this embodiment is a multi-faceted sound device.
[0104] In this embodiment, the substrate 908 is a rectangular parallelepiped structure, which includes four different surfaces 908a, and the four different surfaces are uneven surfaces. The thermosound device 90 includes four thermosound elements 102, of which at least one thermosound element 102 is a composite film, and the other thermosound element 102 may be a graphene film or a carbon nanotube layer.
[0105] Each heating device 104 includes a first electrode 104a and a second electrode 104b, respectively. The first electrode 104a and the second electrode 104b are electrically connected to a thermosound element 102, respectively.
[0106] The thermal sound generating device 90 provided in this embodiment can realize sound propagation in multiple directions.
[0107] See Figure 24 , The tenth embodiment of the present invention provides a thermal sound generating device 100. The thermo-sound device 100 includes a thermo-sound element 102, a substrate 208, and a heat-generating device 1004. The thermo-sound element 102 is disposed on the base 208. The structure of the thermo-sound device 100 provided in this embodiment is basically the same as that of the thermo-sound device 20 provided in the second embodiment. The difference is that in the thermo-sound device 100 provided in this embodiment, the heating device 1004 is A laser, or other electromagnetic wave signal sounding device. The electromagnetic wave signal 1020 emitted from the heating device 1004 is transmitted to the thermosound element 102, and the thermosound element 102 emits sound.
[0108] The heating device 1004 can be disposed directly on the thermosound element 102. When the heating device 1004 is a laser, and when the substrate 208 is a transparent substrate, the laser can be arranged corresponding to the surface of the substrate 208 away from the thermosound element 102, so that the laser light emitted from the laser is transmitted through the substrate 208 To the thermo-sounding element 102. In addition, when the heating device 1004 emits an electromagnetic wave signal, the electromagnetic wave signal can be transmitted to the thermosound element 102 through the substrate 208. At this time, the heating device 1004 can also correspond to the substrate 208 away from the The surface of the thermosound element 102 is provided.
[0109] In the thermosound device 100 of this embodiment, when the thermosound element 102 is irradiated by electromagnetic waves such as laser, the thermosound element 102 is excited by absorbing the energy of the electromagnetic wave, and makes the absorbed light energy through non-radiation. Fully or partially converted to heat. The temperature of the thermosound element 102 changes according to changes in the frequency and intensity of the electromagnetic wave signal 1020, and rapidly exchanges heat with the surrounding air or other gaseous or liquid media, so that the temperature of the surrounding media also changes at equal frequencies. Causes the surrounding medium to expand and contract rapidly, thereby producing sound.
[0110] Because the working principle of the thermo-sounding device is to convert a certain form of energy into heat at an extremely fast speed, and perform rapid heat exchange with the surrounding gas or liquid medium, so that the medium expands and contracts, thereby producing sound. It can be understood that the energy form is not limited to electric energy or light energy, and the heating device is not limited to the electrode or electromagnetic wave signal generator in the above-mentioned embodiment. Anything that can cause the thermally induced sound element to generate heat and heat according to the audio frequency change. The surrounding medium devices can all be regarded as uniform heating devices and fall within the protection scope of the present invention.
[0111] The composite membrane of the present invention has better toughness and mechanical strength, so the composite membrane can be conveniently made into thermo-sound devices of various shapes and sizes. The thermal sound generating device of the present invention can not only be used as a speaker alone, but also can be conveniently applied to various electronic devices requiring a sound generating device. The thermally induced sound device can be built into the housing of the electronic device or on the outer surface of the housing as the sound unit of the electronic device. The thermo-induced sound device can replace the traditional sound unit of the electronic device, and can also be used in combination with the traditional sound unit. The thermo-sound device can be connected to other electronic components of the electronic device, a public power supply or a common processor, etc., and can also be connected to the electronic device in a wired or wireless manner, such as a signal transmission line combined with the USB interface of the electronic device. In a wireless way, for example, it is connected with the electronic device through Bluetooth. The thermo-induced sound device can also be installed or integrated on the display screen of the electronic device as a sound unit of the electronic device. The electronic device can be audio, mobile phone, MP3, MP4, game console, digital camera, digital video camera, TV or computer, etc. For example, when the electronic device is a mobile phone, since the thermo-sound device provided in this embodiment has a transparent structure, the thermo-sound device can be attached to the surface of the mobile phone display screen by mechanical fixing or adhesive. When the electronic device is MP3, the thermal sound generating device can be built into the MP3 and electrically connected to the circuit board inside the MP3. When the MP3 is powered on, the thermal sound generating device can emit sound. It can be understood that the thermo-sound-producing device provided by the present invention can also directly replace the sound-producing elements in existing electronic devices and be applied to electronic devices. Because the thermo-sound-producing device of the present invention has a non-magnetic structure, it has a small volume and Weight, therefore, when it is used in an electronic device instead of an existing sounding device, the weight of the electronic device can be reduced, and the electronic device can also have a smaller volume or an ultra-thin structure.
[0112] In addition, those skilled in the art can also make other changes within the spirit of the present invention. Of course, these changes made according to the spirit of the present invention should all be included in the scope of protection claimed by the present invention.

PUM

PropertyMeasurementUnit
Thickness0.34 ~ 10.0nm

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