Provided are an acoustic diaphragm and an acoustic device including the same. The acoustic diaphragm may include graphene nanoparticles, and an average particle size of the graphene nanoparticles may be about 10 nm or less. The graphene nanoparticles substantially may have a particle size of about 1 nm to about 10 nm. The graphene nanoparticles may include at least one functional group selected from a hydroxyl group, a carboxyl group, a carbonyl group, an epoxy group, an amine group, and an amide group.

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for selecting distributed mode loudspeaker electrodes using an output frequency. One of the methods includes determining, for a piezoelectric transducer, a subset of frequencies, from a range of frequencies, at which to output a sound; selecting, based on the subset of frequencies, one or more electrode pairs from two or more electrode pairs included in the piezoelectric transducer to generate the sound; and providing, by a drive module connected to each of the two or more electrode pairs, current to each of the selected one or more electrode pairs to cause the piezoelectric transducer to generate a force that, when provided to a load, causes the load to generate the sound within the subset of frequencies.

An apparatus comprising a piezoelectric diaphragm positioned between opposing first and second electrodes, the piezoelectric diaphragm comprising a stack of graphene oxide layers between respective electrode-engaging layers of reduced graphene oxide, wherein the apparatus is configured to have one or more of a sound output mode and a sound input mode such that: in the sound output mode, the first and second electrodes are configured to apply a voltage to the reduced graphene oxide layers to generate an electric field across the graphene oxide stack, the generated electric field causing vibration of the piezoelectric diaphragm to produce a sound output wave corresponding to the applied voltage, and in the sound input mode, the reduced graphene oxide layers are configured to collect electrical charge which is induced in the graphene oxide layers by vibration of the piezoelectric diaphragm in response to a sound input wave, the collected electrical charge creating a voltage between the first and second electrodes corresponding to the sound input wave.

A glass sheet composite includes at least two sheets and a liquid layer held between the two sheets, and at least one of the two sheets being a glass sheet. In the glass sheet composite, the two sheets have been disposed so that an edge surface of one of the two sheets and an edge surface of the other sheet are not flush with each other to constitute a step portion having a stair-like shape in a cross-sectional view, and the glass sheet composite further comprising a seal material provided to the step portion to seal up at least the liquid layer.

A display apparatus includes a display module including a display panel configured to display an image, a rear cover on a rear surface of the display module, and a sound generating module at the rear cover and configured to vibrate the display module to generate sound, and a rear surface of the sound generating module is covered by the rear cover.

The present invention relates to a fixed-fixed membrane for a microelectromechanical system (MEMS) microphone. In one embodiment, a MEMS acoustic sensor includes a substrate; a membrane situated parallel to the substrate; and at least one vent formed into the membrane, wherein the at least one vent is a curved opening in the membrane, and wherein the at least one vent is disposed substantially along a length of the membrane.

A sound-generating apparatus and a vehicle including the same are provided. A sound-generating apparatus includes: a plurality of first portions at a vibration region including a bendable region and a peripheral portion connected to the bendable region; and a plurality of second portions between the plurality of first portions, wherein two or more second portions at the bendable region among the plurality of second portions have a cross-sectional shape that differs from a cross-sectional shape of another second portion disposed at the peripheral portion among the plurality of second portions.

A cantilever microphone includes: a substrate; a cantilever including a rotor frame and a plate covering the rotor frame, where the cantilever includes a first edge fixed to the substrate and a second end opposite to the first edge, a plurality of rotor comb fingers is attached to the plate at an edge of the plate adjacent to the second edge; and a stator fixed to the substrate or attached to a sub structure to allow some displacement from the substrate, where the stator includes a plurality of stator comb fingers, and the stator comb fingers are interdigitated with the rotor comb fingers. For the cantilever microphone, high mechanical sensitivity of the cantilever and high electrostatic sensitivity of the comb structure can be implemented, so as to increase the performance or signal-to-noise ratio of the cantilever microphone.

Disclosed is a display device that includes a display panel, sound generating actuators including a first sound generating actuator in a first area of the display panel and a second sound generating actuator in a second area of the display panel, the first and second sound generating actuators configured to vibrate the display panel to generate sound, and a partition between the first sound generating actuator and the second sound generating actuator.

A display apparatus includes a display module including a display panel configured to display an image, a rear cover on a rear surface of the display module, and a sound generating module at the rear cover and configured to vibrate the display module to generate sound, and a rear surface of the sound generating module is covered by the rear cover.