The present invention discloses a MEMS device and an electronics apparatus. The MEMS device comprises: a substrate; a MEMS element placed on the substrate; a cover encapsulating the MEMS element together with the substrate; and a port for the MEMS element to access outside, wherein the port is provided with a filter which has mesh holes and includes electrets to prevent particles from entering into the MEMS element.

A vibration transducer for sensing vibrations includes a first flexible triboelectric member, a second flexible triboelectric member, a plurality of attachment points, a first electrode and a second electrode. The first flexible triboelectric member includes a first triboelectric layer and a material being on a first position on a triboelectric series. A conductive layer is deposited on the second side thereof. The second flexible triboelectric member includes a second triboelectric layer and a material being on a second position on the triboelectric series that is different from the first position on the triboelectric series. The second triboelectric member is adjacent to the first flexible triboelectric member. When the first triboelectric member comes into and out of contact with the second triboelectric member as a result of the vibrations, a triboelectric potential difference having a variable intensity corresponding to the vibrations can be sensed between the first and second triboelectric members.

The present invention provides an electret sheet that exhibits excellent piezoelectricity even by light stress. The electret sheet of the invention is characterized by including a charged porous sheet, in which the electret sheet has a compressive elastic modulus of 80 to 300 MPa when compressively deformed at 25° C. and a 50% compression stress of 120 to 300 kPa at 25° C., and thus has the excellent piezoelectricity for light stress and exhibits the excellent piezoelectricity even by light stress (0.5 N or less) caused by a pulse wave or a breathing.

The present invention provides an electret sheet that exhibits excellent piezoelectricity even by light stress. The electret sheet of the invention is characterized by including a charged porous sheet, in which the electret sheet has a compressive elastic modulus of 80 to 300 MPa when compressively deformed at 25° C. and a 50% compression stress of 120 to 300 kPa at 25° C., and thus has the excellent piezoelectricity for light stress and exhibits the excellent piezoelectricity even by light stress (0.5 N or less) caused by a pulse wave or a breathing.

Ultrasonic transducers that include membrane films and perforated baseplates. An ultrasonic transducer includes a baseplate having a conductive surface with a plurality of apertures, openings, or perforations formed thereon or therethrough, and a membrane film having a conductive surface. The membrane film is positioned adjacent to the apertures, openings, or perforations formed on or through the baseplate. By applying a voltage between the conductive surface of the membrane film and the conductive surface of the baseplate, an electrical force of attraction can be created between the membrane film and the baseplate. Varying this applied voltage can cause the membrane film to undergo vibrational motion. The dimensions corresponding to the size and/or shape of the apertures, openings, or perforations formed on or through the baseplate can be varied so that different regions of the baseplate produce different frequency responses, allowing the net bandwidth of the ultrasonic transducer to be increased.

An electro-acoustic transducer includes: a housing; a fixed electrode; a diaphragm that oscillates in accordance with a potential difference between the diaphragm and the fixed electrode generated based on the electric signal, the diaphragm being provided to face the fixed electrode; and a support part that supports the partial region of the diaphragm toward the fixed electrode, the support part including a displacement part that is displaced in a direction in which the diaphragm is displaced in response to a change in pressure inside the housing, and a contacting part contacts the partial region of the diaphragm, wherein a distance between the diaphragm and the fixed electrode in the partial region is less than a distance between the diaphragm and the fixed electrode outside the partial region.

Low-cost hearing aid platforms that are customizable for specific user needs are disclosed. An exemplary hearing aid platform includes an electret microphone, an amplifier, a capacitor, a printable circuit board (PCB), an audio output, and a housing for the components. The hearing aid platform may comprise customizable gain settings and safety features such as automatic gain control. In some embodiments, the hearing aid platform may connect to headphones. In some embodiments, the hearing aid platform may connect to a bone transducer. Devices described herein also may include housings that are customizable for a user's needs and/or personality.

Low-cost hearing aid platforms that are customizable for specific user needs are disclosed. An exemplary hearing aid platform includes an electret microphone, an amplifier, a capacitor, a printable circuit board (PCB), an audio output, and a housing for the components. The hearing aid platform may comprise customizable gain settings and safety features such as automatic gain control. In some embodiments, the hearing aid platform may connect to headphones. In some embodiments, the hearing aid platform may connect to a bone transducer. Devices described herein also may include housings that are customizable for a user's needs and/or personality.

A condenser microphone with at least two microphone capsules, each including a diaphragm and a backplate. The backplates of both the first capsule and second capsule having an electret bias. The first capsule having a first polar pattern, and the second capsule having a second polar pattern. The second capsule having an external voltage bias that is continuously variable over a certain voltage range. This external voltage bias can be applied to the second diaphragm or second backplate. The microphone's total polar pattern consists of a combination of the first polar pattern and the second polar pattern. Using the external voltage bias of the second capsule, the microphone's total polar pattern is continuously variable throughout a range set by the external voltage bias.

Disclosed are a directional microphone receiver and sound device. The directional microphone receiver includes: a housing and an electret condenser microphone (ECM), where the housing has a first tuning chamber and a second tuning chamber; a side of the housing is provided with a first sound transmission hole and a second sound transmission hole; the first tuning chamber communicates with the first sound transmission hole, and the second tuning chamber communicates with the second sound transmission hole; the ECM is provided between the first tuning chamber and the second tuning chamber, and has a diaphragm, an upper chamber, and a lower chamber; the diaphragm is provided between the upper chamber and the lower chamber; and the lower chamber communicates with the first tuning chamber, and the upper chamber communicates with the second tuning chamber.