TWI450601B - Thermal acoustic device and electric device - Google Patents

Description

Thermal sounding device and electronic device

The present invention relates to a thermo-acoustic device, and more particularly to a graphene-based thermo-acoustic device and an electronic device using the same.

A thermoacoustic device is generally composed of a signal input device and a sounding element, and a signal is input to the sounding element through a signal input device to emit a sound. The thermoacoustic device is one of the sounding devices, which is a thermoacoustic device based on the thermoacoustic effect, see the document "The Thermophone", EDWARD C. WENTE, Vol. XIX, No. 4, p333-345 and " On Some Thermal Effects of Electric Currents", William Henry Preece, Proceedings of the Royal Society of London, Vol. 30, p408-411 (1879-1881). It discloses a thermo-acoustic device that achieves vocalization by introducing alternating current into a conductor. The conductor has a small heat capacity, a thin thickness, and the ability to rapidly transfer heat generated inside it to the surrounding gaseous medium. When the alternating current passes through the conductor, the conductor rapidly rises and falls with the change of the alternating current intensity, and rapidly exchanges heat with the surrounding gaseous medium, causing the surrounding gas medium molecules to move, and the density of the gas medium changes accordingly, thereby generating sound waves.

In addition, HDArnold and IBCrandall disclose a simple thermoacoustic device in the literature "The thermophone as a precision source of sound", Phys. Rev. 10, p22-38 (1917), which uses a platinum sheet for heat. To the sounding component. Limited by the material itself, when the platinum sheet is used as the thermo-acoustic device of the thermoacoustic element, the sound generation frequency is up to 4 kHz and the sound generation efficiency is low.

In view of this, it is indeed necessary to provide a thermoacoustic device having a high sounding frequency and good sounding effect.

A thermo-acoustic device comprising a uniform thermal device and a thermo-acoustic device for supplying energy to the thermo-acoustic component to generate heat for the thermo-acoustic component; wherein the thermo-acoustic component comprises A graphene film.

Compared with the prior art, the thermo-acoustic device provided by the present invention has the following advantages: First, since the thermo-acoustic element in the thermo-acoustic device does not require other complicated structures such as magnets, the structure of the thermo-acoustic device It is relatively simple and is advantageous for reducing the cost of the thermo-acoustic device. Third, since the thickness of the graphene film is thin and the heat capacity is low, the sounding frequency is high and the sounding efficiency is high.

Hereinafter, a thermo-acoustic sounding device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The same components are denoted by the same reference numerals in the following embodiments. The schematic diagrams involved in the embodiments of the present invention are not intended to limit the embodiments in order to better illustrate the embodiments.

Referring to FIG. 1 and FIG. 2, a first embodiment of the present invention provides a thermo-acoustic device 10 that includes a thermo-acoustic component 102 and a uniform thermal device 104.

The heating device 104 is used to provide energy to the thermally-induced sounding element 102, causing the thermally-induced sounding element 102 to generate heat and emit sound. In this embodiment, the heating device 104 provides electrical energy to the thermally-sounding element to cause the thermo-acoustic element 102 to generate 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 to the thermo-acoustic element 102, respectively. In this embodiment, the first electrode 104a and the second electrode 104b are respectively disposed on the surface of the thermoacoustic element 102 and are flush with the opposite sides of the thermoacoustic element 102.

The first electrode 104a and the second electrode 104b in the heating device 104 are used to provide an electrical signal to the thermo-acoustic element 102, causing the thermo-acoustic element 102 to generate Joule heat, and the temperature rises to emit a sound. The first electrode 104a and the second electrode 104b may be in the form of a layer (filament or strip), a rod, a strip, a block or other shapes, and the cross section may have a circular shape, a square shape, a trapezoidal shape, or the like. Triangle, polygon, or other irregular shape. The first electrode 104a and the second electrode 104b may be fixed to the surface of the thermoacoustic element 102 by adhesion of a bonding agent. In order to prevent the heat of the thermo-acoustic element 102 from being excessively absorbed by the first electrode 104a and the second electrode 104b, the contact area of the first electrode 104a and the second electrode 104b with the thermo-acoustic element 102 is small. Therefore, the shape of the first electrode 104a and the second electrode 104b is preferably a filament shape or a ribbon shape. The material of the first electrode 104a and the second electrode 104b may be selected from a metal, a conductive paste, a conductive paste, an indium tin oxide (ITO) or a carbon nanotube.

When the first electrode 104a and the second electrode 104b have a certain intensity, the first electrode 104a and the second electrode 104b may function to support the thermo-acoustic element 102. If the two ends of the first electrode 104a and the second electrode 104b are respectively fixed on one frame, the thermo-acoustic element 102 is disposed on the first electrode 104a and the second electrode 104b, and the thermo-acoustic element 102 passes through the first electrode 104a and The second electrode 104b is suspended.

In the present embodiment, the first electrode 104a and the second electrode 104b are formed of a filament-like silver electrode formed on the thermoacoustic element 102 by a printing method such as screen printing.

The thermoacoustic device 10 further includes a first electrode lead (not shown) and a second electrode lead (not shown), and the first electrode lead and the second electrode lead are respectively associated with the thermal sound generating device 10 An electrode 104a and the second electrode 104b are electrically connected such that the first electrode 104a is electrically connected to the first electrode lead, and the second electrode 104b is electrically connected to the second electrode lead. The thermoacoustic device 10 is electrically connected to an external circuit through the first electrode lead and the second electrode lead.

The thermoacoustic element 102 includes a graphene film which is a two-dimensional structure having a certain area of a film structure. The graphene film has a thickness of from 0.34 nm to 10 nm. The graphene film includes at least one layer of graphene. When the graphene film includes a plurality of graphenes, the multi-layer graphene may overlap each other to form a graphene film to have a larger area of the graphene film; or the multi-layer graphene may be superposed on each other to form a graphene film to make graphite The thickness of the olefin film is increased. Preferably, the graphene film is a single layer of graphene. The graphene is a single-layer two-dimensional planar structure composed of a plurality of carbon atoms by sp ² bonding. The thickness of the graphene may be the thickness of a single layer of carbon atoms. The graphene film has high light transmittance, and the transmittance of the single-layer graphene can reach 97.7%. Therefore, the thermo-acoustic device using the graphene film as the thermo-acoustic element can be a transparent thermo-acoustic device. . Since the thickness of the graphene film is very thin, it has a low heat capacity, and its heat capacity can be less than 2 × 10 ^-3 joules per square centimeter Kelvin, and the heat capacity of the single-layer graphene can be less than 5.57 × 10 ^-4 joules per square Cm Kelvin. The graphene film is a self-supporting structure, and the self-supporting graphene film does not require a large-area carrier support, and as long as the supporting force is provided on opposite sides, the whole film can be suspended to maintain the self-film state, that is, the graphene. When the film is placed (or fixed) on two supports disposed at a fixed distance apart, the graphene film located between the two supports can be suspended to maintain its own film state. Experiments show that graphene is not a 100% smooth and flat two-dimensional film, but a large number of microscopic undulations on the surface of single-layer graphene. This way, single-layer graphene is used to maintain its self-supporting properties. stability.

The method of preparing the graphene film may be a chemical vapor deposition method, an LB method, or a method of tearing off the oriented graphite with a tape. In this embodiment, a graphene film is prepared by chemical vapor deposition. The graphene film is grown on the surface of a metal film substrate by chemical vapor deposition.

The working medium of the thermoacoustic element 102 is not limited, and only needs to satisfy a resistivity higher than that of the thermo-acoustic element 102. The medium includes a gaseous medium or a liquid medium. The gaseous medium can be air. The liquid medium includes one or more of a non-electrolyte solution, water, an organic solvent, and the like. The liquid medium has a resistivity greater than 0.01 ohm·meter. Preferably, the liquid medium is purified water. The pure water has a conductivity of 1.5×10 ⁷ ohm·m, and its heat capacity per unit area is also large, and the heat generated by the thermo-acoustic element 102 can be conducted, so that the thermo-acoustic element 102 can be dissipated. In this embodiment, the medium is air.

The thermo-acoustic device 10 of the present embodiment can be electrically connected to an external circuit through the first electrode 104a and the second electrode 104b, thereby thereby accessing an external signal to sound. Since the thermo-acoustic element 102 includes a graphene film having a small heat capacity per unit area and a large heat dissipation area, the thermo-acoustic element is after the heating device 104 inputs a signal to the thermo-acoustic element 102. 102 can quickly rise and fall temperature, produce periodic temperature changes, and quickly exchange heat with the surrounding medium, so that the density of the surrounding medium changes periodically, and then emits sound. In short, the thermoacoustic element 102 of the embodiment of the present invention achieves vocalization by "electric-thermal-acoustic" conversion. Further, the thermoacoustic device 10 is a transparent thermoacoustic device by utilizing the high transmittance of the graphene film.

The sound intensity level of the thermo-acoustic device 10 provided in this embodiment is greater than 50 decibels per watt of sound pressure level, and the vocalization frequency ranges from 1 Hz to 100,000 Hz (ie, 1 Hz to 100 kHz). The thermoacoustic device may have a distortion of less than 3% in the frequency range of 500 Hz to 10,000 Hz.

Referring to FIG. 3 and FIG. 4, a second embodiment of the present invention provides a thermo-acoustic device 20. The thermo-acoustic device 20 of the present embodiment is different from the thermo-acoustic device 10 of the first embodiment in that the thermo-acoustic device 20 of the present embodiment further includes a substrate 208. The thermoacoustic element 102 is disposed on a surface of the substrate 208. The first electrode 104a and the second electrode 104b are disposed on a surface of the thermoacoustic element 102. The shape, size and thickness of the substrate 208 are not limited, and the surface of the substrate 208 may be a flat surface or a curved surface. The material of the substrate 208 is not limited and may be a hard material or a flexible material having a certain strength. Preferably, the material of the substrate 208 should have a higher electrical resistance than the thermo-acoustic element 102 and have better thermal and thermal resistance to prevent excessive heat generated by the thermo-acoustic element 102 from being absorbed by the substrate 208. Specifically, the insulating material may be glass, ceramic, quartz, diamond, plastic, resin or wood material.

In this embodiment, the substrate 208 includes at least one aperture 208a. The depth of the aperture 208a is less than or equal to the thickness of the substrate 208. When the depth of the hole 208a is less than the thickness of the substrate 208, the hole 208a is a blind hole. When the depth of the hole 208a is equal to the thickness of the substrate 208, the hole 208a is a through hole. The shape of the cross section of the 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 holes 208a, the plurality of holes 208a may be uniformly distributed, distributed in a regular pattern, or randomly distributed to the substrate 208. The spacing of each adjacent two holes 208a is not limited, and is preferably from 100 micrometers to 3 millimeters. In this embodiment, the substrate includes a plurality of holes 208a, which are through holes having a cylindrical shape in cross section and uniformly distributed on the substrate 208.

The thermally audible element 102 is disposed on the surface of the substrate 208 and is suspended relative to the aperture 208a in the substrate 208. In this embodiment, since the portion of the thermo-acoustic element 102 above the hole 208a is suspended, the portions of the thermo-acoustic element 102 are in contact with the surrounding medium, increasing the contact of the thermo-acoustic element 102 with the surrounding gas or liquid medium. The area of the thermally audible element 102 is not easily broken by the fact that another portion of the thermally audible element 102 is in direct contact with the surface of the substrate 208 and is supported by the substrate 208.

Referring to FIG. 5, a third embodiment of the present invention provides a thermo-acoustic device 30. The difference between the thermo-acoustic device 30 provided in this embodiment and the thermo-acoustic device 20 provided in the second embodiment is that, in this embodiment, the base 308 of the thermo-acoustic device 30 includes at least one slot 308a, the slot 308a One surface 308b is disposed on the substrate 308. The depth of the groove 308a is less than the thickness of the substrate 308. The slot 308a can be a blind slot or a slot. When the slot 308a is a blind slot, the length of the slot 308a is less than the distance between the two opposing sides of the base 308. When slot 308a is a through slot, the length of slot 308a is equal to the distance between the two opposing sides of substrate 308. The groove 308a causes the surface 308b to form an uneven surface. The depth of the groove 308a is smaller than the thickness of the substrate 308, and the length of the groove 308a is not limited. The shape of the groove 308a on the surface 308b of the substrate 308 may be rectangular, arcuate, polygonal, oblate, or other irregular shape. Referring to FIG. 5, in the embodiment, the substrate 308 is provided with a plurality of grooves 308a, which are blind grooves, and the groove 308a has a rectangular shape on the surface 308b of the substrate 308. Referring to FIG. 6, the groove 308a has a rectangular cross section in the longitudinal direction thereof, that is, the groove 308a has a rectangular parallelepiped structure. Referring to FIG. 7, the groove 308a has a triangular cross section in the longitudinal direction thereof, that is, the 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 in a regular pattern or randomly distributed on the surface 308b of the substrate 308. Referring to FIG. 7, the groove pitch of two adjacent blind grooves may be close to zero, that is, the area where the substrate 308 is in contact with the thermo-acoustic element 102 is a plurality of lines. It can be understood that in other embodiments, by changing the shape of the groove 308a, the area where the thermo-acoustic element 102 contacts the substrate 308 is a plurality of points, that is, between the thermo-acoustic element 102 and the substrate 308. Point contact, line contact or face contact.

In the thermo-acoustic device 30 of the present embodiment, since the substrate 308 includes at least one groove 308a, the groove 308a can reflect sound waves emitted by the thermo-acoustic element 102, thereby enhancing the thermo-acoustic device 30 in heat-induced manner. The vocal intensity of the sound emitting element 102 side. When the distance between the adjacent grooves 308a is close to zero, the substrate 308 can support both the thermoacoustic element 102 and the maximum surface area of the thermo-acoustic element 102 in contact with the surrounding medium.

It can be understood that when the depth of the groove 308a reaches a certain value, the sound wave reflected by the groove 308a is superimposed with the original sound wave, thereby causing destructive interference, affecting the sounding effect of the thermo-acoustic element 102. To avoid this, it is preferable that the depth of the groove 308a is 10 mm or less. In addition, when the depth of the groove 308a is too small, the thermo-acoustic element 102 suspended by the substrate 308 is too close to the substrate 308, which is disadvantageous for heat dissipation of the thermo-acoustic element 102. Therefore, preferably, the depth of the groove 308a is greater than or equal to 10 microns.

Referring to FIG. 8 and FIG. 9, a fourth embodiment of the present invention provides a thermal sound generating device 40. The difference between the thermo-acoustic device 40 provided in this embodiment and the thermo-acoustic device 20 provided in the second embodiment is that the substrate 408 of the thermo-acoustic device 40 is a mesh structure in this embodiment. 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 interdigitated to form a base 408 of a mesh structure. 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 mutually 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 extend along the first direction L1, and between the adjacent first linear structures 408a. The distances can be equal or not equal. The distance between the adjacent two first linear structures 408a is not limited, and preferably, the pitch is less than or equal to 1 cm. In this embodiment, the plurality of first linear structures 408a are equally spaced apart, and the distance between the adjacent two first linear structures 408a is 2 cm. The plurality of second linear structures 408b are spaced apart from each other and extend substantially in the second direction L2 in the axial direction, and the distance between the adjacent second linear structures 408b may be equal or unequal. The distance between the adjacent two second linear structures 408b is not limited, and preferably, the pitch is less than or equal to 1 cm. The first direction L1 forms an angle α with the second direction L2, and α is greater than 0 degrees and less than or equal to 90 degrees. In this embodiment, the angle between the first direction L1 and the second direction L2 is 90°. The manner in which the plurality of first linear structures 408a are disposed to intersect with the plurality of second linear structures 408b is not limited. In this embodiment, the first linear structure 408a and the second linear structure 408b are woven with each other to form a mesh structure. In another embodiment, the plurality of spaced apart second linear structures 408b are disposed on the same side of the plurality of first linear structures 408a. The contact portion of the plurality of second linear structures 408b and the plurality of first linear structures 408a may be fixedly disposed by a bonding agent, or may be fixedly disposed by soldering. When the melting point of the first linear structure 408a is low, the second linear structure 408b may be fixedly disposed with the first linear structure 408a by hot pressing.

The substrate 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 that are disposed to intersect each other. The mesh 408c is quadrangular. The mesh 408c may be square, rectangular or diamond-shaped depending on the angle at which the plurality of first linear structures 408a and the plurality of second linear structures 408b are disposed at intersections. The size of the mesh 408c is determined by the distance between the adjacent two first linear structures 408a and the distance between the adjacent two second linear structures 408b. In this embodiment, the plurality of first linear structures 408a and the plurality of second linear structures 408b are disposed in parallel at equal intervals, and the plurality of first linear structures 408a and the plurality of second linear structures are The 408b are perpendicular to each other, so the mesh 408c is square and has a side length of 2 cm.

The diameter of the first linear structure 408a is not limited, and is preferably 10 micrometers to 5 millimeters. The material of the first linear structure 408a is made of an insulating material including fibers, plastics, resins or silicones. The first linear structure 408a may be a textile material. Specifically, the first linear structure 408a may include one or more of plant fibers, animal fibers, wood fibers, and mineral fibers, such as cotton, twine, and wool. Silk thread, nylon thread or spandex. Preferably, the insulating material should have certain heat resistant properties and flexibility, such as nylon or polyester. In addition, the first linear structure 408a may also be a conductive wire having an insulating layer on its outer surface. The conductive filaments may be wire or nanocarbon line-like structures. The metal includes a metal element or an alloy, and the elemental metal may be aluminum, copper, tungsten, molybdenum, gold, titanium, rhodium, palladium or iridium. The metal alloy may be an alloy of any combination of the above elemental metals. The material of the insulating layer may be resin, plastic, cerium oxide or metal oxide. In this embodiment, the first linear structure 408a is a nano carbon line-like structure coated with cerium oxide on the surface, and the insulating layer composed of cerium oxide encapsulates the nano carbon line-like structure to constitute the first line. Shaped structure 408a.

The structure and material of the second linear structure 408b are the same as those 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 nanocarbon line-like structure whose surface is coated with an insulating layer.

The nanocarbon line-like structure includes at least one nanocarbon line, and the nanocarbon line includes a plurality of carbon nanotubes. The carbon nanotubes may be one or more of a single-walled carbon nanotube, a double-walled carbon nanotube, and a multi-walled carbon nanotube. The nanocarbon line may be a pure structure composed of a plurality of carbon nanotubes. When the nanocarbon line-like structure includes a plurality of nanocarbon lines, the plurality of nanocarbon lines may be disposed in parallel with each other. When the nanocarbon line-like structure includes a plurality of nanocarbon lines, the plurality of nano carbon lines may be spirally wound with each other. The plurality of nanocarbon lines in the nanocarbon line structure can also be fixed to each other by a binder.

The nanocarbon line may be a non-twisted nano carbon line or a twisted nano carbon line. Referring to FIG. 10, the non-twisted nanocarbon pipeline includes a plurality of carbon nanotubes extending along the length of the nanocarbon pipeline and connected end to end. Preferably, the non-twisted nanocarbon pipeline comprises a plurality of carbon nanotube segments, the plurality of carbon nanotube segments being connected end to end by van der Waals, and each of the carbon nanotube segments comprises a plurality of mutually parallel and A carbon nanotube that is tightly bonded by van der Waals. That is, the non-twisted nanocarbon pipeline includes a plurality of carbon nanotubes extending in the same direction. The carbon nanotubes in the extending direction are connected to each other by van der Waals force. The carbon nanotube segments have any length, thickness, uniformity, and shape. The non-twisted nano carbon line is not limited in length and has a diameter of 0.5 nm to 100 μm.

The twisted nanocarbon line is obtained by twisting the non-twisted nanocarbon line in the opposite direction using a mechanical force. Referring to FIG. 11, the twisted nanocarbon pipeline includes a plurality of carbon nanotubes arranged in an axial spiral arrangement around the carbon nanotubes. Preferably, the twisted nanocarbon pipeline comprises a plurality of carbon nanotube segments, the plurality of carbon nanotube segments being connected end to end by van der Waals, and each of the carbon nanotube segments comprises a plurality of mutually parallel and A carbon nanotube that is tightly bonded by van der Waals. The carbon nanotube segments have any length, thickness, uniformity, and shape. The twisted nanocarbon line is not limited in length and has a diameter of 0.5 nm to 100 μm. The nano carbon pipeline and its preparation method can be found in Fan Shoushan et al., which was filed on November 5, 1991 in the Republic of China. No. I303239, announced on November 21, 1997, Taiwan’s patent "a carbon nanotube rope and Its manufacturing method", the patentee: Hon Hai Precision Industry Co., Ltd., and Taiwan No. I312337 announced on July 21, 1998, the Taiwan Announced Patent "Nano Carbon Pipe and Its Manufacturing Method", Patentee: Hon Hai Precision Industry Co., Ltd. In order to save space, only the above is cited, but all the technical disclosures of the above application are also considered as part of the disclosure of the present application.

The substrate 408 of the thermo-acoustic device 40 of the present embodiment having the mesh structure has the following advantages: First, the mesh structure includes a plurality of meshes, which can provide heat to the thermally-sounding element 102 while providing heat-induced The sounding element 102 has a large contact area with the surrounding medium. Second, the base 408 of the mesh structure can have better flexibility, and therefore, the thermo-acoustic device 40 has better flexibility. Third, when the first linear structure 408a or/and the second linear structure 408b includes a nanocarbon line-like structure coated with an insulating layer, the nanocarbon line-like structure may have a smaller diameter and further increase The contact area of the thermoacoustic element 102 with the surrounding medium; the nanocarbon line-like structure has a small density, and therefore, the mass of the thermo-acoustic device 40 can be small; the nanocarbon line-like structure has better flexibility. It can be bent many times without being damaged, and therefore, the thermo-acoustic device 40 can have a longer service life.

It can be understood that the mesh structure of the substrate 408 in this embodiment can also be woven from at least one of the above various linear structures. When the substrate 408 includes a linear structure, the one linear structure can be bent and intersected a plurality of times to form a mesh structure.

Referring to FIG. 12, a fifth embodiment of the present invention provides a thermo-acoustic device 50. The difference between the thermo-acoustic device 50 provided in this embodiment and the thermo-acoustic device provided in the second embodiment is that in the embodiment, the base 508 of the thermo-acoustic device 50 is a carbon nanotube composite structure.

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 carbon nanotube layer includes a plurality of uniformly distributed carbon nanotubes. The carbon nanotubes may be one or more of a single-walled carbon nanotube, a double-walled carbon nanotube, and a multi-walled carbon nanotube. The carbon nanotubes in the carbon nanotube layer can be tightly bonded by van der Waals force. The carbon nanotubes in the carbon nanotube layer are disordered or ordered. The disordered arrangement here means that the arrangement direction of the carbon nanotubes is irregular, and the ordered arrangement here means that at least most of the arrangement of the carbon nanotubes has a certain regularity. Specifically, when the carbon nanotube layer includes a disordered arrangement of carbon nanotubes, the carbon nanotubes may be entangled or isotropically arranged; when the carbon nanotube layer comprises an ordered arrangement of carbon nanotubes, The carbon nanotubes are arranged in a preferred orientation in one direction or in a plurality of directions. The thickness of the carbon nanotube layer is not limited and may be from 0.5 nm to 1 cm. Preferably, the carbon nanotube layer may have a thickness of from 100 μm to 1 mm. The carbon nanotube layer further includes a plurality of micropores formed by a gap between the carbon nanotubes. The pores in the carbon nanotube layer may have a pore diameter of 50 μm or less. The carbon nanotube layer may include at least one layer of carbon nanotube film, a carbon nanotube film or a carbon nanotube film.

Referring to FIG. 13, the carbon nanotube film comprises a plurality of carbon nanotubes connected to each other by van der Waals force. The plurality of carbon nanotubes are arranged in a preferred orientation along substantially the same direction. The preferred orientation means that the overall extension direction of most of the carbon nanotubes in the carbon nanotube film is substantially in the same direction. Moreover, the overall extension direction of the majority of the carbon nanotubes is substantially parallel to the surface of the carbon nanotube film. Further, most of the carbon nanotubes in the carbon nanotube film are connected end to end by van der Waals force. Specifically, each of the carbon nanotubes of the majority of the carbon nanotubes extending in the same direction in the carbon nanotube film is connected end to end with the carbon nanotubes adjacent in the extending direction by van der Waals force . Of course, there are a small number of randomly arranged carbon nanotubes in the carbon nanotube film, and these carbon nanotubes do not significantly affect the overall orientation of most of the carbon nanotubes in the carbon nanotube film. The carbon nanotube film is a self-supporting film. The self-supporting carbon nanotube film does not require a large-area carrier support, and as long as the support force is provided on both sides, it can be suspended in the whole to maintain its own film state, that is, the carbon nanotube film is placed (or When fixed on two supports arranged at a fixed distance, the carbon nanotube film located between the two supports can be suspended to maintain its own film state. The self-supporting is mainly achieved by the presence of continuous carbon nanotubes extending through the end-to-end extension of the van der Waals force in the carbon nanotube film.

The carbon nanotube film may have a thickness of 0.5 nm to 100 μm, and the width and the length are not limited, and are set according to the size of the second substrate 108. The specific structure of the carbon nanotube film and its preparation method can be found in Fan Shoushan et al., which was filed on February 12, 1996. The Republic of China announced the patent No. I327177 announced on July 11, 1999. To save space, reference is made only to this, but all technical disclosures of the application should also be considered as part of the disclosure of the technology of the present application.

When the carbon nanotube layer comprises a multi-layered carbon nanotube film, the angle of intersection formed between the extending directions of the carbon nanotubes in the adjacent two layers of carbon nanotube film is not limited.

Referring to FIG. 14, the carbon nanotube flocculation membrane is a carbon nanotube membrane formed by a flocculation method. The carbon nanotube flocculation membrane comprises carbon nanotubes which are intertwined and uniformly distributed. The carbon nanotubes are attracted and entangled with each other by van der Waals force to form a network structure. The carbon nanotube flocculation membrane is isotropic. The length and width of the carbon nanotube film are not limited. Since the carbon nanotubes are intertwined in the carbon nanotube flocculation membrane, the carbon nanotube flocculation membrane has good flexibility and is a self-supporting structure, which can be bent and folded into any shape without breaking. . The area and thickness of the carbon nanotube film are not limited, and the thickness is 1 micrometer to 1 millimeter. For the carbon nanotube flocculation membrane and the preparation method thereof, please refer to the patent application "Nano Carbon" of the No. 200844041 published by Fan Shoushan et al. on May 11, 1996 in the Republic of China on November 16, 1997. Method for preparing tube film". In order to save space, only the above is cited, but all the technical disclosures of the above application are also considered as part of the technical disclosure of the present application.

Referring to FIG. 15, the carbon nanotube rolled film comprises uniformly distributed carbon nanotubes, and the carbon nanotubes are arranged in the same direction or in different directions. The 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 by van der Waals force and tightly combined. The carbon nanotubes in the carbon nanotube rolled film form an angle β with the surface of the growth substrate forming the carbon nanotube array, wherein β is greater than or equal to 0 degrees and less than or equal to 15 degrees. The carbon nanotubes in the carbon nanotube rolled film have different arrangements depending on the manner of rolling. 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 crushed in different directions, the carbon nanotubes can be arranged in a preferred orientation in a plurality of directions. The thickness of the carbon nanotube rolled film is not limited, and is preferably from 1 μm to 1 mm. The area of the carbon nanotube rolled film is not limited, and is determined by the size of the carbon nanotube array that is rolled out of the film. When the size of the carbon nanotube array is large, a large area of the carbon nanotube rolled film can be crushed. The carbon nanotube rolling film and the preparation method thereof are described in Fan Shoushan et al., which was filed on June 29, 1996, and the No. I334851 announced on December 21, 1999 in Taiwan, the Taiwanese patent "nano carbon tube" Method for preparing a film". In order to save space, only the above is cited, but all the technical disclosures of the above application are also considered as part of the technical disclosure of the present application.

The insulating material layer is located on the surface of the carbon nanotube layer, and the insulating material layer functions to insulate the carbon nanotube layer from the thermoacoustic element 102. The layer of insulating material is only distributed on the surface of the carbon nanotube layer, or the layer of insulating material wraps each of the carbon nanotubes in the carbon nanotube layer. When the thickness of the insulating material layer is thin, the micropores in the carbon nanotube layer are not blocked, and therefore, the carbon nanotube composite structure includes a plurality of micropores. The thermally audible element 102 is at least partially suspended relative to the plurality of microwells. The plurality of micropores provide a large contact area of the thermoacoustic element 102 with the outside.

The thermo-acoustic device 50 provided in this embodiment adopts a carbon nanotube composite structure as the substrate 508, and has the following advantages: First, the carbon nanotube composite structure includes a carbon nanotube layer and is coated on the carbon nanotube layer. The surface of the insulating material layer, because the carbon nanotube layer can be composed of pure carbon nanotubes, the carbon nanotube layer has a small density and relatively light mass, and therefore, the thermo-acoustic device 50 has a small The quality is convenient for application; secondly, the microporous system in the carbon nanotube layer is composed of a gap between the carbon nanotubes and is evenly distributed. In the case where the insulating material layer is thin, the carbon nanotube composite structure can be maintained. The uniformly distributed microporous structure, therefore, the thermo-acoustic element 102 can be more uniformly contacted with the outside air through the substrate 508; thirdly, the carbon nanotube layer has good flexibility and can be bent multiple times. It is not damaged, therefore, the carbon nanotube composite structure has better flexibility, and the thermo-acoustic device 50 using the carbon nanotube composite structure as the substrate 508 is a flexible sounding device, which can be set to any shape without limitation. .

Referring to FIG. 16 and FIG. 17, a sixth embodiment of the present invention provides a thermo-acoustic device 60. The thermo-acoustic device 60 includes a substrate 608, a heat-consisting device 104, and a thermo-acoustic component 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 thermo-acoustic elements 102, respectively.

The plurality of first electrodes 104a and the plurality of second electrodes 104b are alternately spaced apart from each other on the substrate 608. The thermo-acoustic component 102 is disposed on the plurality of first electrodes 104a and the plurality of second electrodes 104b, such that the plurality of first electrodes 104a and the plurality of second electrodes 104b are located on the substrate 608 and the thermo-acoustic component 102. The thermally audible element 102 is partially suspended relative to the substrate 608. That is, the plurality of first electrodes 104a, the plurality of second electrodes 104b, the thermally audible elements 102, and the substrate 608 are collectively formed with a plurality of gaps 601, thereby causing the thermally audible elements 102 to have a large contact area with the surrounding air. The distance between each adjacent first electrode 104a and second electrode 104b may or may not be equal. Preferably, the distance between each adjacent first electrode 104a and the 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 centimeter.

The substrate 608 mainly functions to carry the first electrode 104a and the second electrode 104b. The shape and size of the substrate 608 are not limited, and the material is an insulating material or a material having poor conductivity. In addition, the material of the substrate 608 should have better thermal insulation properties, so that the heat generated by the thermoacoustic element 102 is prevented from being absorbed by the substrate 608, and the purpose of heating the surrounding medium and sounding is not achieved. In this embodiment, the material of the substrate 608 may be glass, resin or ceramic. In this embodiment, the substrate 608 is a square glass plate having a side length of 4.5 cm and a thickness of 1 mm.

The gap 601 is defined by a first electrode 104a, a second electrode 104b and a substrate 608. 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 of the first electrode 104a and the second electrode 104b ranges from 1 micrometer to 1 centimeter. Preferably, the height of the first electrode 104a and the second electrode 104b is 15 microns.

The first electrode 104a and the second electrode 104b may be in the form of a layer (filament or strip), a rod, a strip, a block or other shapes, and the cross section may have a circular shape, a square shape, a trapezoidal shape, or the like. Triangle, polygon, or other irregular shape. The first electrode 104a and the second electrode 104b may be fixed to the substrate 608 by bolting or bonding of a bonding agent or the like. In order to prevent the heat of the thermo-acoustic element 102 from being excessively absorbed by the first electrode 104a and the second electrode 104b, the contact area of the first electrode 104a and the second electrode 104b with the thermo-acoustic element 102 is small. Therefore, the shape of the first electrode 104a and the second electrode 104b is preferably a filament shape or a ribbon shape. The material of the first electrode 104a and the second electrode 104b may be selected from a metal, a conductive paste, a conductive paste, indium tin oxide (ITO), a carbon nanotube or a carbon fiber. When the material of the first electrode 104a or the second electrode 104b is a carbon nanotube, the first electrode 104a or the second electrode 104b may be a nanocarbon line-like structure. The structure of the nanocarbon line-like structure is the same as that of the nanocarbon line-like structure provided in the fourth embodiment. Since the carbon nanotubes in the nanocarbon line-like structure are connected end to end, the nanocarbon line-like structure has good electrical conductivity and can be used as an electrode.

The thermo-acoustic 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 associated with the first electrode 104a and the second electrode in the thermo-acoustic device 60. The electrodes 104b are connected such that a plurality of first electrodes 104a are electrically connected to the first electrode leads 610, respectively, and a plurality of second electrodes 104b are electrically connected to the second electrode leads 612, respectively. The thermoacoustic device 60 is electrically connected to an external circuit through the first electrode lead 610 and the second electrode lead 612. This connection can greatly reduce the sheet resistance of the thermo-acoustic element 102 between the first electrode lead 610 and the second electrode lead 612, and can improve the sound-emitting efficiency of the thermo-acoustic element 102.

In this embodiment, the plurality of first electrodes 104a and the plurality of second electrodes 104b can function to support the thermo-acoustic element 102, and therefore, the substrate 608 is not an essential component. When the thermo-acoustic device 60 in this embodiment does not include the substrate 608, the first electrode 104a and the second electrode 104b can also protect and support the thermo-acoustic component while electrically connecting the thermo-acoustic element 102 to an external circuit. 102.

In this embodiment, the first electrode 104a and the second electrode 104b are filamentary silver electrodes formed by a screen printing method. The number of the first electrodes 104a is four, and the number of the second electrodes 104b is four. The four first electrodes 104a and the four second electrodes 104b 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 μm, and a distance between the adjacent first electrode 104a and the second electrode 104b is 5 mm.

In the thermo-acoustic device 60 provided in this embodiment, the thermo-acoustic element 102 is suspended by the plurality of first electrodes 104a and the plurality of second electrodes 104b, which increases the contact area between the thermo-acoustic element 102 and the surrounding air, which is advantageous. The heat-induced sounding element 102 exchanges heat with the surrounding air, improving sound generation efficiency.

Referring to FIG. 18 and FIG. 19, a seventh embodiment of the present invention provides a thermal sound generating device 70. The thermoacoustic device 70 includes a substrate 608, a uniform thermal device 104, and a pyrogenic component 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 thermo-acoustic elements 102, respectively. The thermoacoustic element 102 includes a graphene film. The thermo-acoustic device 70 provided in this embodiment has substantially the same structure as the thermo-acoustic device 60 provided in the sixth embodiment, except that in the present embodiment, two adjacent first electrodes 104a and second are provided. At least one spacer element 714 is further included between the electrodes 104b.

The spacer element 714 and the substrate 608 can be separate components that are secured to the substrate 608 by, for example, bolting or adhesive bonding. Additionally, the spacer element 714 can also be integrally formed with the substrate 608, i.e., the spacer element 714 is of the same material as the substrate 608. The spacer element 714 is not limited in shape and may be in the form of a sphere, a filament or a ribbon. In order to maintain the thermal sounding element 102 with a good vocalization effect, the spacer element 714 should have a smaller contact area with the thermally audible element 102 while supporting the thermoacoustic element 102, preferably the spacer element 714 and the thermal vocalization The elements 102 are in point or line contact.

In the present embodiment, the material of the spacer member 714 is not limited, and may be an insulating material such as glass, ceramic, or resin, or may be a conductive material such as a metal, an alloy, or an indium tin oxide. When the spacer element 714 is a conductive material, it is electrically insulated from the first electrode 104a and the second electrode 104b, and, preferably, the spacer element 714 is parallel to the first electrode 104a and the second electrode 104b. The height of the spacer element 714 is not limited, and is preferably 10 micrometers to 1 centimeter. In this embodiment, the spacer element 714 is a filament-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, and is 20 micrometers. The spacer element 714 is disposed 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 thermoacoustic elements 102 are located on the same plane.

The thermoacoustic element 102 is disposed on the spacer element 714, the first electrode 104a, and the second electrode 104b. The thermoacoustic element 102 is spaced apart from the substrate 608 by the spacer element 714, and forms a space 701 with the substrate 608, the space 701 being the first electrode 104a or the second electrode 104b, the spacer element 714, substrate 608 and thermally audible element 102 are formed together. Further, in order to prevent the thermo-acoustic element 102 from generating standing waves, maintaining the good sound-generating effect of the thermo-acoustic element 102, the distance between the thermo-acoustic element 102 and the substrate 608 is preferably 10 micrometers to 1 centimeter. In this embodiment, since the heights of the first electrode 104a, the second electrode 104b, and the spacer element 714 are 20 micrometers, the thermoacoustic element 102 is disposed on the first electrode 104a, the second electrode 104b, and the spacer element 714. The distance between the thermoacoustic element 102 and the substrate 608 is 20 microns.

It can be understood that the first electrode 104a and the second electrode 104b also have a certain supporting effect on the thermo-acoustic element 102, but when the distance between the first electrode 104a and the second electrode 104b is large, the thermo-acoustic element 102 is The support effect is not good, and the spacer element 714 is disposed between the first electrode 104a and the second electrode 104b, so as to better support the thermo-acoustic element 102, and the thermo-acoustic element 102 is spaced apart from the substrate 608 and the substrate The 608 is formed with a space 701 to ensure that the thermo-acoustic element 102 has a good vocalization effect.

Referring to FIG. 20, an eighth embodiment of the present invention provides a thermal sound generating device 80. The thermoacoustic device 80 includes at least one pyrogenic device and a plurality of thermo-acoustic elements. The plurality of thermo-acoustic elements include two types: first, the number of the plurality of thermo-acoustic elements is at least two, and the thermo-acoustic elements are not in contact with each other; and second, the plurality of thermal-induced sounds The number of components is one, and the thermo-acoustic component is disposed on a substrate having a curved surface such that a plurality of normal directions are formed or the thermo-acoustic components are bent and disposed on different planes. The heating means may correspond to the thermo-acoustic elements one-to-one, or one heating means may correspond to a plurality of thermo-acoustic elements. The heating device may also be a unitary structure composed of a plurality of portions corresponding to the plurality of thermo-acoustic elements. In this embodiment, the thermo-acoustic device 80 includes a first heating device 804, a second heating device 806, a substrate 208, a first thermo-acoustic component 802a, and a second thermo-acoustic component 802b.

The substrate 208 includes a first surface (not labeled) and a second surface (not labeled). The shape, size and thickness of the substrate 208 are not limited. The first surface and the second surface may be planar, curved or rugged surfaces. The first surface and the second surface may be two adjacent surfaces or two opposite surfaces. In this embodiment, the substrate 208 has a rectangular parallelepiped structure, and the first surface and the second surface are two opposite surfaces. The substrate 208 further includes a plurality of through holes 208a penetrating the first surface and the second surface such that the first surface and the second surface become uneven surfaces. The plurality of through holes 208a may be disposed in parallel with each other.

The first thermo-acoustic component 802a is disposed on the first surface of the substrate 208 and is at least partially suspended relative to the first surface. The second thermo-acoustic element 802b is disposed on the second surface and is at least partially suspended relative to the second surface. The first thermo-acoustic element 802a is a graphene film. The second thermoacoustic element 802b is a graphene film or a carbon nanotube layer. The structure of the carbon nanotube layer is the same as that of the carbon nanotube layer disclosed in the fifth embodiment. Since the carbon nanotube layer includes at least one layer of carbon nanotube film, the thickness of the carbon nanotube layer is small and has a small heat capacity per unit area, and therefore, the carbon nanotube layer can also function as a thermo-acoustic element.

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 electrically connected to the first thermo-acoustic element 802a, respectively. In this embodiment, the first electrode 104a and the second electrode 104b are respectively disposed on the surface of the first thermo-acoustic element 802a and flush with two opposite sides of the first thermo-acoustic 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 thermo-acoustic element 802b, respectively. In this embodiment, the first electrode 104a and the second electrode 104b are respectively disposed on the surface of the second thermo-acoustic element 802b and are flush with the opposite sides of the first thermo-acoustic element 802a.

The thermo-acoustic device 80 provided in this embodiment is a double-sided sounding device, and by providing a thermo-acoustic component on two different surfaces, the range of sound emitted by the thermo-acoustic component can be made larger and clearer. It is possible to control the heating device to make any of the thermoacoustic elements emit sound, or to simultaneously emit sound, so that the thermoacoustic device can be used in a wider range. Further, when one of the thermo-acoustic elements fails, the other thermo-acoustic element can continue to operate, increasing the service life of the thermo-acoustic device.

Referring to FIG. 21, a ninth embodiment of the present invention provides a thermo-acoustic sounding device 90. The difference between the structure of the thermo-acoustic device 90 provided in this embodiment and the thermo-acoustic device 80 provided in the eighth embodiment is that the thermo-acoustic device 90 provided in this embodiment is a multi-faceted sound-emitting device.

In this embodiment, the substrate 908 is a rectangular parallelepiped structure comprising four different surfaces, the four different surfaces being rugged surfaces. The thermo-acoustic device 90 includes four thermo-acoustic elements 102, one of which is a graphene film, and the other three of the thermo-acoustic elements 102 may be a graphene film or a carbon nanotube. Floor.

Each of the heating devices 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 thermo-acoustic element 102, respectively.

The thermo-acoustic device 90 provided in this embodiment can realize the propagation of sound in a plurality of directions.

Referring to FIG. 22, a tenth embodiment of the present invention provides a thermo-acoustic device 100. The thermoacoustic device 100 includes a thermo-acoustic component 102, a substrate 208, and a uniform thermal device 1004. The thermally audible element 102 is disposed on the substrate 208. The difference between the structure of the thermo-acoustic device 100 provided in this embodiment and the thermo-acoustic device 20 provided in the second embodiment is that in the thermo-acoustic device 100 provided in the embodiment, the heating device 1004 is a laser. , or other electromagnetic wave signal generating device. The electromagnetic wave signal 1020 emitted from the heating device 1004 is transmitted to the thermo-acoustic element 102, and the thermo-acoustic element 102 sounds.

The heat generating device 1004 can be disposed on the thermoacoustic element 102. When the heating device 1004 is a laser, when the substrate 208 is a transparent substrate, the laser can be disposed away from the surface of the substrate 208 away from the thermo-acoustic element 102, thereby causing the laser to be emitted from the laser. Laser light is transmitted through the substrate 208 to the thermoacoustic element 102. In addition, when the electromagnetic device 1004 emits an electromagnetic wave signal, the electromagnetic wave signal can be transmitted to the thermo-acoustic component 102 through the substrate 208. At this time, the heating device 1004 can also correspond to the substrate 208 away from the heat. The surface of the sound producing element 102 is disposed.

In the thermoacoustic device 100 of the present embodiment, when the thermoacoustic element 102 is irradiated with an electromagnetic wave such as a laser, the thermoacoustic element 102 is excited by absorbing the energy of the electromagnetic wave, and the absorbed light is absorbed by the non-radiation. Can be converted to heat in whole or in part. The temperature of the thermoacoustic element 102 changes according to the frequency and intensity of the electromagnetic wave signal 1020, and is rapidly exchanged with the surrounding air or other gas or liquid medium, so that the temperature of the surrounding medium also changes with the frequency. Causes the surrounding medium to expand and contract rapidly, thereby making a sound.

Since the thermoacoustic device works by converting a certain form of energy into heat at an extremely fast rate and performing rapid heat exchange with the surrounding gas or liquid medium, the medium expands and contracts to emit 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 embodiment, and any of the thermo-acoustic elements can be heated and heated according to audio changes. The means of surrounding medium can be considered as a consistent thermal device and is within the scope of the present invention.

The graphene film of the present invention has good toughness and mechanical strength, so the graphene film can be conveniently fabricated into thermoacoustic devices of various shapes and sizes. The thermoacoustic device of the present invention can be used not only as a speaker alone but also in various electronic devices requiring a sounding device. The thermo-acoustic device can be built in the housing of the electronic device or on the outer surface of the housing as a sounding unit of the electronic device. The thermoacoustic device can replace the conventional sounding unit of the electronic device, or can be used in combination with a conventional sounding unit. The thermo-acoustic device can be used in conjunction with other electronic components of the electronic device or a utility processor or the like. It can also be connected to the electronic device through a wired or wireless manner, such as by a signal transmission line and a USB interface of the electronic device, and wirelessly connected to the electronic device, for example, via Bluetooth. The thermoacoustic device can also be mounted or integrated on the display screen of the electronic device as a sounding unit of the electronic device. The electronic device can be an audio, a mobile phone, an MP3, an MP4, a game console, a digital camera, a digital video camera, a television or a computer. For example, when the electronic device is a mobile phone, since the thermo-acoustic device provided by the embodiment is a transparent structure, the thermo-acoustic device can be attached to the surface of the display screen of the mobile phone by mechanical fixing or adhesive. When the electronic device is an MP3, the thermo-acoustic device can be built in the MP3 and electrically connected to the circuit board inside the MP3. When the MP3 is powered on, the thermo-acoustic device can emit sound.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10;20;30;40;50;60;70;80;90;100. . . Thermal sounding device

102. . . Thermoacoustic component

104; 1004. . . Heating device

104a. . . First electrode

104b. . . Second electrode

208; 308; 408; 508; 608; 908. . . Base

208a. . . hole

308a. . . groove

308b. . . surface

408a. . . First linear structure

408b. . . Second linear structure

408c. . . Mesh

601. . . gap

610. . . First electrode lead

612. . . Second electrode lead

714. . . Spacer element

802a. . . First thermoacoustic element

802b. . . Second thermoacoustic element

804. . . First uniform heat device

806. . . Second heating device

1020. . . Electromagnetic wave signal

1 is a top plan view of a thermo-acoustic device according to a first embodiment of the present invention.

Figure 2 is a cross-sectional view taken along line II-II of Figure 1.

3 is a top plan view of a thermo-acoustic device according to a second embodiment of the present invention.

Figure 4 is a cross-sectional view taken along line IV-IV of Figure 3.

Fig. 5 is a plan view showing a thermo-acoustic device according to a third embodiment of the present invention.

Figure 6 is a cross-sectional view taken along line VI-VI of Figure 5 in a case of the third embodiment.

Figure 7 is a cross-sectional view taken along line VI-VI of Figure 5 in another case of the third embodiment.

Figure 8 is a plan view of a thermo-acoustic device according to a fourth embodiment of the present invention.

Figure 9 is a cross-sectional view taken along line IX-IX of Figure 8.

Figure 10 is a scanning electron micrograph of the non-twisted nanocarbon line structure used in the thermoacoustic device of Figure 8.

Figure 11 is a scanning electron micrograph of a twisted nanocarbon line-like structure employed in the thermoacoustic device of Figure 8.

Figure 12 is a side cross-sectional view showing a thermoacoustic device using a carbon nanotube layer coated with an insulating layer as a substrate according to a fifth embodiment of the present invention.

Figure 13 is a scanning electron micrograph of the carbon nanotube film used in the carbon nanotube layer of Figure 12.

Figure 14 is a scanning electron micrograph of the carbon nanotube flocculation membrane used in the carbon nanotube layer of Figure 12.

Figure 15 is a scanning electron micrograph of a carbon nanotube rolled film used in the carbon nanotube layer of Figure 12.

Figure 16 is a plan view of a thermo-acoustic device according to a sixth embodiment of the present invention.

Figure 17 is a cross-sectional view taken along line XVII-XVII of Figure 16.

Figure 18 is a plan view of a thermoacoustic device according to a seventh embodiment of the present invention.

Figure 19 is a cross-sectional view taken along line XIX-XIX of Figure 18.

Figure 20 is a side cross-sectional view showing a thermoacoustic device according to an eighth embodiment of the present invention.

Figure 21 is a side cross-sectional view showing a thermoacoustic device according to a ninth embodiment of the present invention.

Figure 22 is a side view of a thermoacoustic device according to a tenth embodiment of the present invention.

50. . . Thermal sounding device

104. . . Heating device

104a. . . First electrode

104b. . . Second electrode

508. . . Base

102. . . Thermoacoustic component

Claims (18)

A thermo-acoustic device comprising:
a substrate;
a thermally audible element disposed on a surface of the substrate;
a uniform thermal device for providing energy to the thermo-acoustic component to cause the thermo-acoustic component to generate heat;
The improvement is that the thermo-acoustic element comprises a graphene film, the substrate comprises a carbon nanotube composite structure, the carbon nanotube composite structure comprises a carbon nanotube layer and is coated on the nano carbon A layer of insulating material on the surface of the tube layer. The thermoacoustic device according to claim 1, wherein the graphene film comprises a plurality of layers of graphene which are overlapped with each other or stacked on each other. The thermoacoustic device according to claim 1, wherein the graphene film is a single layer of graphene. The thermoacoustic device according to claim 1, wherein the graphene film has a thickness of from 0.34 nm to 10 nm. The thermoacoustic device according to claim 1, wherein the carbon nanotube layer comprises a layer of carbon nanotube film or a plurality of layers of carbon nanotube film stacked on each other. The thermoacoustic device according to claim 5, wherein the carbon nanotube film comprises a plurality of carbon nanotubes connected end to end and extending in a preferred orientation in the same direction. The thermoacoustic device according to claim 5, wherein the carbon nanotube film comprises a plurality of carbon nanotubes intertwined and uniformly distributed by van der Waals force. The thermoacoustic device according to claim 1, wherein the carbon nanotube composite structure has a plurality of micropores, and the graphene film is suspended at a position corresponding to the micropores. The thermoacoustic device according to claim 1, wherein the insulating material layer is coated on a surface of a carbon nanotube in the carbon nanotube layer. The thermoacoustic device according to claim 1, wherein the graphene film is insulated from the carbon nanotube layer by the insulating material layer. The thermoacoustic device of claim 1, wherein the heating device comprises a first electrode and a second electrode electrically connected to the thermo-acoustic element, respectively. The thermoacoustic device according to claim 1, wherein the heating device is an electromagnetic wave signal generating device. The thermoacoustic device of claim 12, wherein the heating device is a laser. An electronic device, wherein the sound-emitting device of the electronic device comprises the thermo-acoustic device according to any one of claims 1 to 13. The electronic device of claim 14, wherein the thermo-acoustic device is built in the electronic device or directly disposed on an outer casing of the electronic device. The electronic device of claim 14, wherein the thermo-acoustic device is connected to the electronic device via a USB interface or wirelessly connected to the electronic device via Bluetooth. The electronic device of claim 14, wherein the electronic device comprises an audio, a mobile phone, an MP3, an MP4, a game machine, a digital camera, a digital video camera, a television or a computer. The electronic device of claim 14, wherein the electronic device further comprises a display screen, the thermal sound generating device being disposed on a surface of the display screen.