A thermal excitation acoustic-wave-generating device includes a first heating element, a substrate that includes a main surface along which the first heating element is disposed, and a facing body that faces the substrate with the first heating element interposed therebetween. The substrate and the facing body define a path for an acoustic wave. A length of the path is close to a whole number multiple of of a wavelength of the acoustic wave.

A thermoacoustic device includes an outer shell having two half shells, each half shell having an outer flange and an inner region. The half shells are joined at the outer flanges such that the combined half shell inner regions define an inner cavity. A gas is provided within the outer shell inner cavity, and a substrate having electrodes is supported within the outer shell. A thermoacoustic element is mounted on the substrate in contact with the electrodes. Leads extend into the shell where they are joined to the electrodes. In further embodiments, the device is provided with a gas source and a regulator for controlling gas pressure in the inner cavity.

This disclosure provides systems, methods, and apparatus associated with an electrostatically driven graphene speaker. In one aspect, a device includes a graphene membrane, a first frame on a first side of the graphene membrane, and a second frame on a second side of the graphene membrane. The first frame and the second frame both include substantially circular open regions that define a substantially circular portion of the graphene membrane. A first electrode is proximate the first side of the circular portion of the graphene membrane. A second electrode proximate the second side of the circular portion of the graphene membrane.

A thermoacoustic transducer apparatus is disclosed including at least one thermal converter operable to provide power conversion between acoustic power and thermal power in a pressurized working gas contained within a working volume, a portion of which extends through the thermal converter. The thermoacoustic transducer is operable to cause a periodic flow in the working gas during operation. The apparatus also includes a reservoir volume in fluid communication with the working volume through a conduit having a working volume end in fluid communication with the working volume and a reservoir volume end in fluid communication with the reservoir volume. The conduit has a bore size and length operable to cause pressure oscillations at the working volume end to be converted to flow oscillations at the reservoir volume end such that periodic fluid flow at the reservoir volume end is at least twice as large as periodic fluid flow at the working volume end thereby facilitating a steady fluid flow along the conduit for equalization of working gas static pressures between the working volume and the reservoir volume while providing a sufficiently high acoustic impedance at the working volume end to minimize losses due to periodic flows of working gas within the conduit.

This disclosure provides systems, methods, and apparatus associated with an electrostatically driven graphene speaker. In one aspect, a device includes a graphene membrane, a first frame on a first side of the graphene membrane, and a second frame on a second side of the graphene membrane. The first frame and the second frame both include substantially circular open regions that define a substantially circular portion of the graphene membrane. A first electrode is proximate the first side of the circular portion of the graphene membrane. A second electrode proximate the second side of the circular portion of the graphene membrane.

Described herein is the use of large phase transformational strain in relaxor ferroelectric single crystals for broadband sound generation. The technique exploits the thermo-optical triggering and thus an opto-acoustic effect of ferroelectric phase transformation piezocrystals under mechanical bias conditions.

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.

A speaker system with a thermoelectric conversion device includes a basin frame and a vibration system and a magnetic circuit system that are accommodated in the basin frame. The vibration system includes a diaphragm and a voice coil. The magnetic circuit system includes a T-iron, a magnet and a washer, with a magnetic gap between the washer and the magnet and the T-iron. The voice coil moves up and down in the magnetic gap. A thermoelectric conversion device is connected to the speaker including a thermoelectric power generation module, a boost circuit module, and a load management module. The thermoelectric power generation module is fixedly connected to a back surface of the T-iron for thermoelectric power generation. The boost circuit module boosts and regulates a direct current outputted by the thermoelectric power generation module. The load management module performs a power distribution and load management on the boosted new power.

A MEMS transducer for interacting with a volume flow of a fluid includes a substrate which includes a layer stack having a plurality of layers which form a plurality of substrate planes, and which includes a cavity within the layer stack. The MEMS transducer includes an electromechanical transducer connected to the substrate within the cavity and including an element which is deformable within at least one plane of movement of the plurality of substrate planes, deformation of the deformable element within the plane of movement and the volume flow of the fluid being causally correlated. The MEMS transducer includes an electronic circuit arranged within a layer of the layer stack, the electronic circuit being connected to the electromechanical transducer and being configured to provide a conversion between a deformation of the deformable element and an electric signal.

A thermoacoustic device includes a stage coupled to a bar, wherein the stage includes a first heating component on a first terminus of the stage. The stage further includes a first cooling component on a second terminus of the stage. A thermal conductivity of the stage is higher than a thermal conductivity of the bar. A heat capacity of the stage is higher than a heat capacity of the bar.