Abstract: A pressure wave generating element is provided that includes a support and a heat generating layer that is provided on the support and generates heat by energization. Moreover, the heat generating layer includes a fiber with at least a partial metal coating on a surface.

Abstract: A flexible variable frequency ultrasonic therapeutic probe based on thermoacoustic effect of a carbon nanotube film comprises an ultrasonic sound production element, and a heat dissipation layer and an acoustic matching layer located on both sides thereof. The sound production element comprises a carbon nanotube film, metal electrodes and wires, and the shape and size of the sound production element can be adjusted according to the actual functional requirements. When a signal is accessed into the sound production element, the carbon nanotube film produces a corresponding temperature change, which causes the surrounding media to expand and contract and to excite ultrasonic waves. The present invention greatly improves the coupling efficiency between the probe and the subject, reduces the energy loss of ultrasonic waves, and enhances the uniformity of the sound intensity distribution in the affected part.

Abstract: This disclosure includes several different features suitable for use in circumaural and supra-aural headphones designs. Designs that include earpad assemblies that improve acoustic isolation are discussed. User convenience features that include automatically detecting the orientation of the headphones on a user's head are also discussed. Various power-saving features, design features, sensor configurations and user comfort features are also discussed.

Abstract: A thermal excitation acoustic-wave-generating device includes a first acoustic wave source that includes a first heating element and a substrate that includes a main surface along which the first heating element is disposed, a second acoustic wave source that includes a second heating element and a facing body that includes a main surface along which the second heating element is disposed, and a pair of electrodes connected to the first and second heating elements. The first and second acoustic wave sources are arranged such that the first and second heating elements are separated from each other and face each other. The pair of electrodes are disposed between the first and second acoustic wave sources.

Abstract: A photoacoustic photon meter includes: a photoacoustic generative array including carbon nanotubes disposed in a photoacoustic generating pattern, such that the carbon nanotubes: receive photons comprising optical energy, and produce thermal energy from the optical energy; and a superstratum including a thermally expandable elastomer on which the photoacoustic generative array is fixedly disposed in position on the superstratum to spatially conserve the photoacoustic generating pattern, and such that the superstratum: is optically transparent to the photons; receives the thermal energy from the photoacoustic generative array; expands and contracts in response to receipt of the thermal energy; and produces photoacoustic pressure waves in response to the expansion and contraction, the photoacoustic pressure waves including a photoacoustic intensity and photoacoustic frequency that are based upon an amount of optical pressure applied to the carbon nanotubes by the photons, a spatial photon fluence of the photons

Abstract: The present disclosure provides a sound device, comprising a housing and a sound unit received in the housing, wherein, the housing comprises an upper cover plate with a receiving space, the upper cover plate is made of 3D glass, and the upper cover plate and the sound unit are fixed to each other by laser welding. The sound device provided by the present disclosure replacing the housing with a 3D glass housing, and thus enhances the strength of the housing, and the sealing and fixing is implemented by laser welding due to the transparent property of the 3D glass, which effectively prevents overflowing caused by gluing and ultrasonic welding, meanwhile the maximum cavity is ensured and the usage of the antenna will not be affected.

Abstract: A thermoacoustic device includes a loop pipe, a first stack that is disposed in the loop pipe and that generates a sound wave in the loop pipe by way of a temperature gradient, a second stack that is disposed in the loop pipe and that generates a temperature gradient, a first high temperature side heat exchanger that is disposed at one end of the first stack and that makes the temperature of the one end of the first stack be higher than the other end, and a first low temperature side heat exchanger that is disposed at the other end of the first stack and that makes the temperature of the other end of the first stack be lower than the one end.

Abstract: A thermoacoustic device is provided with a housing having at least one open face. An active element is supported within the housing, and at least two electrodes are provided in electrical contact with the active element. A membrane is provided to cover each open face of the housing. The housing and membrane assembly is filled with a liquid. A signal lead is joined to the electrodes within the housing to communicate with the exterior of the housing. The active element can be made from a carbon nanotube sheet, and a gas can be provided in contact with the active element.

Abstract: Photoacoustic probes include reflective surfaces situated to redirect scattered or reflected optical radiation from a specimen surface back to the specimen. A reflective coating can reflect probe radiation while transmitting visible radiation so that a technician can view the specimen. One or more optical fibers and acoustic transducers can be secured to a lens or other substrate on which the reflective surface is defined. The light collector is configured to block scattered light so that an operator and a subject are not exposed to the scattered light.

Abstract: A hearing device, particularly a hearing aid, has a housing, a signal processing unit arranged in the housing, a first sound generator disposed in the housing, and a second sound generator. The first sound generator and the second sound generator are configured to convert an output signal from the signal processing unit into sound. The second sound generator is a thermo-acoustic transducer.

Abstract: A method for making thermoacoustic device includes following steps. A substrate having a first surface and second surface is provided. The first surface defines a plurality of grids. Grooves are formed on each of the plurality of grids. A first electrode and a second electrode are formed on each grid. The first electrode is spaced from the second electrode. One of the grooves is located between the first electrode and the second electrode. A number of carbon nanotube wires are applied on the first surface and electrically connected to the first electrode and the second electrode. A thermoacoustic device array is formed on the substrate by separating the carbon nanotube wires. A number of thermoacoustic device is formed by cutting the substrate according to the grids.

Abstract: A hearing device, particularly a hearing aid, has a housing, a signal processing unit arranged in the housing, a first sound generator disposed in the housing, and a second sound generator. The first sound generator and the second sound generator are configured to convert an output signal from the signal processing unit into sound. The second sound generator is a thermo-acoustic transducer.

Abstract: A carbon nanotube thermophone is provided which includes a urethane frame having mounting holes at corners of the frame. Screw holes in the frame are provided for a cable holder. A square shaped carbon nanotube material chip is positioned within the urethane frame. The carbon nanotube material chip can comprise multiple carbon nanotube sheets to electrically tune the impedance to match a driving amplifier impedance load. Wooden spacers assist in positioning the carbon nanotube material chip. A first end of a cable is soldered to the carbon nanotube material chip at electrodes of the material chip. A high temperature rated silicon sealant is used for attachment points on the thermophone.

Abstract: A carbon nanotube thermophone is provided. The thermophone includes high temperature rated shells as protective walls as the top and bottom housing of the thermophone with carbon nanotube sheets affixed between the shells. The shells act as acoustic windows that match the surrounding frequency and acoustic radiation medium. A high temperature rated sealant gasket is used to enclose the shells of the thermophone where gas holes are inserted for interior heavy gas filling. The acoustic resonant frequency is defined by the dimensions of the housing of the thermophone and the sound speed of the filled heavy gas. Each carbon nanotube sheet has an electrode at both ends. Multiple carbon nanotube sheets can electrically tune the impedance to match a driving amplifier impedance load.

Abstract: A method for transferring a carbon nanotube array includes providing a substitute substrate, a growing substrate, and a carbon nanotube array. The carbon nanotube array is grown on the growing substrate. The substitute substrate has a surface having microstructures located thereon. A carbon nanotube structure can be drawn from the carbon nanotube array. The carbon nanotube structure includes carbon nanotube segments joined end-to-end. The carbon nanotube array is transferred from the growing substrate onto the substitute substrate. During transfer, the structural integrity of the carbon nanotube array is maintained.

Abstract: A method for transferring a carbon nanotube array includes providing a substitute substrate, a growing substrate, and a carbon nanotube array. The carbon nanotube array is grown on the growing substrate. A carbon nanotube structure can be drawn from the carbon nanotube array. The carbon nanotube structure includes carbon nanotube segments joined end-to-end. The carbon nanotube array is transferred from the growing substrate onto the substitute substrate. During transfer, the structural integrity of the carbon nanotube array is maintained.

Abstract: A suspended nanotube film (or films) producing sound by means of the thermoacoustic (TA) effect is encapsulated between two plates, at least one of which vibrates, to enhance sound generation efficiency and protect the film. To avoid the oxidation of carbon nanotubes at elevated temperatures and reduce the thermal inertia of surrounding medium the enclosure is filled with inert gas (preferably with high heat capacity ratio, ?=Cp/Cv, and low heat capacity, Cp). To generate sound directly as the first harmonic of applied audio signal without use of an energy consuming dc biasing, an audio signal modulated carrier frequency at much higher frequency is used to provide power input. Various other inventive means are described to provide enhanced projected sound intensity, increased projector efficiency, and lengthened projector life, like the use of infrared reflecting coatings and particles on the projector plates, non-parallel sheet alignment in sheet stacks, and cooling means on one projector side.

Abstract: A photoacoustic transducer, such as a photoacoustic probe includes an optical fiber, diaphragm, at the optical fiber, whereby the optical fiber and diaphragm define a cavity, and an energy absorption film at the optical fiber, whereby an activating laser directed through the optical fiber can excite the energy absorption film to thereby generate an acoustic wave that, upon reflection upon a remote surface, can deflect the diaphragm and modify reflection of a detecting laser also directed through the optical fiber. A method of detecting an acoustic wave includes directing an activating laser through an optical fiber to an energy absorption film at the optical fiber, directing a detecting laser through the optical fiber and cavity to the diaphragm at the optical fiber, and measuring an interference pattern generated at least in part by reflection of the detecting laser from a surface of the diaphragm.

Abstract: A thermoacoustic device includes a first substrate, a sound wave generator, a first electrode, a second electrode and a second substrate. A number of recesses are defined on a surface of the first substrate. The sound-producing parts of the wave generator are located on the surface and suspended over the recesses to enable very rapid expansion by heat, and contraction. The first electrode and the second electrode are spaced from each other and electrically connected to the sound wave generator. The sound wave generator is held in place by the first substrate and the second substrate. A number of through holes are defined by the second substrate. Some of the through holes correspond with the recesses to allow the output of sound.

Abstract: A thermoacoustic device includes a substrate, a sound wave generator and a signal device. The substrate has a net structure and includes a number of first wires and a number of second wires. The first wires and the second wires are crossed with each other. Each of the first wires includes a composite wire. The composite wire includes a carbon nanotube wire structure and a coating layer wrapping the carbon nanotube wire structure. The sound wave generator is located on a surface of the substrate and includes a carbon film. The signal input device is configured to input signals to the sound wave generator.

Abstract: Embodiments of the invention include a micro speaker assembly that has two drivers, each having a separate yoke, set of magnets, voice coil, and acoustic diaphragms. One driver may produce high frequency (HF) sound while the other produces low frequency (LF) sound. The two drivers may be packaged, side-by-side, within the same micro speaker acoustic enclosure. The drivers may have their respective magnet systems physically connected to each other, in order to enhance heat transfer from one to the other. In particular, a thermally conductive portion or bridge may be used to directly join or thermally connect adjacent edges of the yoke portions of the two magnet systems, in order to enhance heat transfer between the first and second micro speaker drivers. Thus, the assembly can handle more power without overheating. Other embodiments are also described and claimed.

Abstract: An earphone includes a loudspeaker, a signal process, an audio signal input port, and a driving port. The loudspeaker includes a thermoacoustic device disposed in a housing. The signal processor is electrically connected to the loudspeaker to provide signal to the loudspeaker. The audio input port is electrically connected to the signal processor to provide audio signal. The power supply device is electrically connected to the signal processor to provide driving current. The thermoacoustic device includes a substrate, and the substrate defines a plurality of grooves, a sound wave generator is suspended on the plurality of grooves.

Abstract: An earphone includes a loudspeaker, a signal process, an audio signal input port, and a driving port. The loudspeaker includes a thermoacoustic device disposed in a housing. The signal processor is electrically connected to the loudspeaker to provide signal to the loudspeaker. The audio input port is electrically connected to the signal processor to provide audio signal. The driving port is electrically connected to the signal processor to provide driving signal. The thermoacoustic device includes a substrate, and the substrate defines a number of grooves, a sound wave generator is suspended on the grooves.

Abstract: An earphone includes a loudspeaker, a signal process, an audio signal input port, and a driving port. The loudspeaker includes a thermoacoustic device disposed in a housing. The signal processor is electrically connected to the loudspeaker to provide signal to the loudspeaker. The audio input port is electrically connected to the signal processor to provide audio signal. The power supply device is electrically connected to the signal processor to provide driving current. The thermoacoustic device includes a substrate, and the substrate defines a plurality of grooves, a sound wave generator is suspended on the plurality of grooves.

Abstract: A room heating device includes a supporting body, a thermoacoustic element, a first electrode and a second electrode. The thermoacoustic element is disposed on the supporting body. The first electrode and the second electrode are connected to the thermoacoustic element. The first electrode is spaced apart from the second electrode.

Abstract: An earphone includes a housing and a thermoacoustic device. The housing has a hollow structure. The thermoacoustic device is disposed in the housing. The thermoacoustic device includes a substrate, a sound wave generator, a first electrode and a second electrode. The first electrode and the second electrode are spaced from each other and electrically connected to the sound wave generator. The substrate includes a first surface and a second surface opposite to the first surface. The first surface defines a number of recesses parallel with and spaced from each other. A depth of each of the recesses ranges from about 100 micrometers to about 200 micrometers. The sound wave generator is located on the first surface of the substrate. The sound wave generator includes a carbon nanotube structure that is suspended over the recesses.

Abstract: There is provided a loudspeaker apparatus which has a diaphragm and a magnet system for driving the diaphragm. The loudspeaker apparatus also has a light source and a cooling device (K) having at least one cooling unit for cooling the at least one light source. The light source is thermally coupled to the first cooling unit. The first cooling unit with the at least one light source is arranged in front of the diaphragm. The outside of the diaphragm can have light reflecting properties.

Abstract: A thermoacoustic device includes a substrate, a sound wave generator, an insulating layer, a first electrode and a second electrode. The first electrode and the second electrode are spaced from each other and electrically connected to the sound wave generator. The substrate includes a first surface and a second surface opposite to the first surface. The first surface defines a plurality of grooves, and a bulge is formed between the adjacent two grooves. The insulating layer is located on the first surface, and continuously attached on the grooves and the bulge. The sound wave generator is located on the insulating layer. The sound wave generator defines a first portion and a second portion. The first portion is suspended on the grooves. The second portion is attached on the bulge.

Abstract: A thermoacoustic device comprise a substrate, a number of thermoacoustic units on the substrate, a number of switches, a driving integrated circuit, a scanning integrated circuit, and a common electrode. The switches are electrically connected to the thermoacoustic units. Each of the switches is electrically connected in series between the first electrode and the driving integrated circuit through a driving electrode. Each of the switches is electrically connected to the scanning integrated circuit through a scanning electrode. The common electrode is electrically connected to the second electrode of the number of thermoacoustic units.

Abstract: A thermoacoustic device includes a sound wave generator and a signal input device. The sound wave generator includes a composite structure. The composite structure includes a carbon nanotube film structure and a graphene film. The carbon nanotube film structure includes a number of carbon nanotubes and micropores. The graphene film is located on a surface of the carbon nanotube film structure, and covers the micropores.

Abstract: A thermoacoustic device includes a sound wave generator and a signal input device. The sound wave generator includes a carbon film. The carbon film includes at least one carbon nanotube layer and at least one graphene layer stacked on each other. The signal input device inputs signals to the sound wave generator.

Abstract: A bobbin includes a stratiform composite structure. The stratiform composite structure includes an amorphous carbon structure and a carbon nanotube film structure composited with the amorphous carbon structure. The amorphous carbon structure and the carbon nanotube film structure are combined by van der Waals attractive force and covalent bonds therebetween.

Abstract: A thermoacoustic device includes a substrate, at least two sound wave generators and at least two signal input devices. The substrate has at least two surfaces. Each of the at least two sound wave generators is located on each of the at least two surfaces. At least one of the at least two sound wave generator includes a carbon film. The carbon film includes at least one carbon nanotube layer and at least one graphene layer stacked with each other. The at least two signal input devices are configured to input signals to the at least two sound wave generator in a one by one manner.

Abstract: A thermoacoustic device includes a substrate, at least two sound wave generators and at least two signal input devices. The substrate has at least two surfaces. Each of the at least two sound wave generators is located on each of the at least two surfaces. At least one of the at least two sound wave generator includes a carbon film. The carbon film includes at least one carbon nanotube layer and at least one graphene layer stacked with each other. The at least two signal input devices are configured to input signals to the at least two sound wave generator separately.

Abstract: A thermoacoustic device includes a carbon nanotube composite structure, a sound wave generator and a signal input device. The carbon nanotube composite structure includes a carbon nanotube structure and a matrix. The matrix is located on a surface of the carbon nanotube structure. The sound wave generator is located on a surface of the carbon nanotube composite structure and insulated from the carbon nanotube structure via the coating layer. The sound wave generator includes a carbon film. The signal input device is configured to input signals to the sound wave generator.

Abstract: A thermoacoustic device includes an electrode layer and a sound wave generator. The sound wave generator is disposed on a surface of the sound wave generator. The electrode layer includes a plurality of insulated wires and a plurality of conductive wires. The conductive wires are disposed apart from each other and crossed with the insulated wires. The sound wave generator is electrically connected with conductive wires.

Abstract: A magnet assembly for a audio speaker provides a gap through which a voice coil assembly passes. A magnetic member, a yoke, and a pole piece form a magnetic circuit that focuses magnetic energy in the gap. A spider movably supports the voice coil assembly. The spider is coupled to one of the magnetic member or the yoke by forming the one of the magnetic member or the yoke in two parts and joining the two parts with a portion of the spider between the two parts. The spider may be formed from a thin film thermoplastic, such as polyetheretherketone (PEEK), and may be less than 10 microns thick. The portion of the spider that is between the two parts may be shaped such that a portion of the two parts are in direct contact with one another.

Abstract: Systems and methods to remove heat from an acoustic enclosure are provided. An apparatus for reproducing acoustic signals includes an acoustic enclosure comprising an acoustic volume. A heat producing element is coupled to the acoustic enclosure, and a thermally conductive structure is thermally coupled to the heat producing element. The thermally conductive structure includes a first surface. A first passive radiator includes a first diaphragm. The first diaphragm extends over at least a portion of the first surface and moves in response to pressure variations within the acoustic volume. Movement of the first diaphragm causes air to flow over the first surface, to facilitate heat removal from the thermally conductive structure.

Abstract: A thermoacoustic device comprise a substrate, a number of thermoacoustic units on the substrate, a number of switches, a driving integrated circuit, a scanning integrated circuit, and a common electrode. The switches are electrically connected to the thermoacoustic units. Each of the switches is electrically connected in series between the first electrode and the driving integrated circuit through a driving electrode. Each of the switches is electrically connected to the scanning integrated circuit through a scanning electrode. The common electrode is electrically connected to the second electrode of the number of thermoacoustic units.

Abstract: A thermoacoustic device includes a first substrate, a sound wave generator, a first electrode, a second electrode and a second substrate. A number of recesses are defined on a surface of the first substrate. The sound-producing parts of the wave generator are located on the surface and suspended over the recesses to enable very rapid expansion by heat, and contraction. The first electrode and the second electrode are spaced from each other and electrically connected to the sound wave generator. The sound wave generator is held in place by the first substrate and the second substrate. A number of through holes are defined by the second substrate. Some of the through holes correspond with the recesses to allow the output of sound.

Abstract: A method for making a thermoacoustic module is disclosed. An insulating substrate and a sound wave generator are provided. A conductive paste is screen printed on the insulating substrate to form a first patterned conductive paste layer. The sound wave generator is placed on the first patterned conductive paste layer and at least partially suspended above the insulating substrate by the patterned conductive paste layer.

Abstract: A thermoacoustic device includes a carbon nanotube composite structure, a sound wave generator and a signal input device. The carbon nanotube composite structure includes a carbon nanotube structure and a matrix. The matrix is located a surface of the carbon nanotube structure. The sound wave generator is located on a surface of the carbon nanotube composite structure and insulated from the carbon nanotube structure via the matrix. The sound wave generator includes a graphene layer including at least one graphene. The signal input device is configured to input signals to the sound wave generator.

Abstract: A thermoacoustic device array includes a substrate and a plurality of thermoacoustic device units located on a surface of the substrate. The substrate defines a number of recesses on the surface, and the recesses are spaced from and parallel with each other. Each thermoacoustic device unit includes a sound wave generator, a first electrode and a second electrode. The first electrode and the second electrode are spaced from each other and electrically connected to the sound wave generator. The sound wave generator is located on the surface and suspended over the recesses. At least one of the recesses is located between the first electrode and the second electrode, and one portion of the sound wave generator that is between the first electrode and the second electrode is suspended over the at least one of the recesses.

Abstract: An earphone includes a housing and a thermoacoustic device. The housing has a hollow structure. The thermoacoustic device is disposed in the housing. The thermoacoustic device includes a substrate, a sound wave generator, a first electrode and a second electrode. The first electrode and the second electrode are spaced from each other and electrically connected to the sound wave generator. The substrate includes a first surface and a second surface opposite to the first surface. The first surface defines a number of recesses parallel with and spaced from each other. A depth of each of the recesses ranges from about 100 micrometers to about 200 micrometers. The sound wave generator is located on the first surface of the substrate. The sound wave generator includes a carbon nanotube structure that is suspended over the recesses.

Abstract: An earphone includes a loudspeaker, a signal process, an audio signal input port, and a driving port. The loudspeaker includes a thermoacoustic device disposed in a housing. The signal processor is electrically connected to the loudspeaker to provide signal to the loudspeaker. The audio input port is electrically connected to the signal processor to provide audio signal. The power supply device is electrically connected to the signal processor to provide driving current. The thermoacoustic device includes a substrate, and the substrate defines a plurality of grooves, a sound wave generator is suspended on the plurality of grooves.

Abstract: A thermoacoustic chip includes a substrate, a sound wave generator, a first electrode, and a second electrode, and an integrated circuit chip. The substrate has a first surface. The sound wave generator is located on the first surface of the substrate. The first electrode and a second electrode are spaced from each other and electrically connected to the sound wave generator. The integrated circuit chip is located on the substrate and electrically connected to the first electrode and the second electrode.

Abstract: A thermoacoustic device includes a substrate, a sound wave generator, an insulating layer, a first electrode and a second electrode. The first electrode and the second electrode are spaced from each other and electrically connected to the sound wave generator. The substrate includes a first surface and a second surface opposite to the first surface. The first surface defines a plurality of grooves, and a bulge is formed between the adjacent two grooves. The insulating layer is located on the first surface, and continuously attached on the grooves and the bulge. The sound wave generator is located on the insulating layer. The sound wave generator defines a first portion and a second portion. The first portion is suspended on the grooves. The second portion is attached on the bulge.

Abstract: A thermoacoustic chip includes a shell having a hole and a speaker located in the shell. The speaker includes a substrate having a surface, a sound wave generator located on the surface of the substrate and opposite to the hole of the shell, and, a first electrode and a second electrode. The first electrode and the second electrode are spaced from each other and electrically connected to the sound wave generator.

Abstract: A thermoacoustic device includes a PCB substrate, a speaker installed on the PCB substrate and including a sound wave generator, and an IC chip installed on the PCB substrate. The speaker and the IC chip are electrically connected by the PCB substrate. The IC chip input an audio signal to the speaker. The speaker heats surrounding medium intermittently according to the input signal so that the surrounding medium to produce a sound by expansion and contraction.

Abstract: A thermoacoustic device includes a sound wave generator and a signal input device. The sound wave generator includes a graphene layer. The graphene layer includes at least one graphene. The signal input device inputs signals to the sound wave generator.