This disclosure provides systems, methods, and device associated with an electrostatically driven graphene speaker. In one aspect, the device includes a graphene membrane having a diameter of about 3 millimeters to about 11 millimeters, and a first electrode proximate a first side of the graphene membrane, the first electrode being electrically conductive. The device is a microphone or a loudspeaker.

A method for making thermoacoustic device includes following steps. A silicon substrate having a first surface and second surface opposite to the first surface is provided. The first surface is patterned by forming a plurality of grooves substantially oriented along a first direction, wherein the plurality of grooves is spaced from each other, and a bulge is formed between each two adjacent grooves. An insulating layer is coated on the patterned surface. A first electrode and a second electrode are formed on the insulating layer, wherein the first electrode and the second electrode are spaced from each other. A carbon nanotube structure is applied on the insulating layer, wherein the carbon nanotube structure is electrically connected to the first electrode and the second electrode, the carbon nanotube structure is suspended above the plurality of grooves.

To manufacture a thermoacoustic energy converting element part, a plurality of first plates and a plurality of second plates are formed. The first plate is provided with a plurality of linear penetration slits which are in parallel with each other and separated along a direction perpendicular to an extending direction of the slit. The slit penetrates the first plate in a thickness direction. The second plate is not provided with any penetration slit. A plate assembly is formed by layering some of the plurality of first plates between adjacent two of the plurality of second plates of which main surfaces face each other. The plate assembly is provided with a plurality of communicating passages formed with the penetration slits adjoining each other in a layering direction. Portions of the assembly at both ends in the extending direction of the penetration slits are cut off to open the communicating passages on both sides of the assembly.

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.

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.

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.

This disclosure provides a device that includes a graphene membrane and a first electrode proximate a first side of the graphene membrane, the first electrode being electrically conductive. The device further includes a frame comprising a first part and a second part, wherein the graphene membrane is suspended between the first part and the second part. The device is configured to have a frequency response across a frequency range at least from 20 Hz to 20 kHz or across the entire human audible frequency range. The device is a microphone or a loudspeaker.

A pressure wave-generating device having a support and a heating element film that is disposed over the support and that is configured to generate heat by energization, and the heating element film has a porous metal structure.

A pressure wave generating element that includes a support; a fiber layer on the support, the fiber layer containing a fiber having a surface thereof at least partially coated with a metal coating, and the fiber in the fiber layer being oriented in a predetermined direction; and a pair of electrodes arranged so as to apply a voltage in an orientation direction of the fiber of the fiber layer.

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.