In accordance with embodiments of the present disclosure, a device may include a piezoelectric speaker for generating sound, a microphone, and a controller communicatively coupled to the speaker and the microphone. The controller may be configured to receive a first signal from the piezoelectric speaker, the first signal induced at least in part by sound incident on the speaker other than sound generated by the piezoelectric speaker, receive a second signal from the microphone, the second signal induced by sound incident on the microphone, process at least one of the first signal and the second signal to determine at least one characteristic of sound incident upon at least one of the piezoelectric speaker and the microphone, and select at least one of the microphone and the piezoelectric speaker as a signal source for incident sound based on the at least one characteristic.

In accordance with embodiments of the present disclosure, a device may include a piezoelectric speaker for generating sound, a microphone, and a controller communicatively coupled to the speaker and the microphone. The controller may be configured to receive a first signal from the piezoelectric speaker, the first signal induced at least in part by sound incident on the speaker other than sound generated by the piezoelectric speaker, receive a second signal from the microphone, the second signal induced by sound incident on the microphone, process at least one of the first signal and the second signal to determine at least one characteristic of sound incident upon at least one of the piezoelectric speaker and the microphone, and select at least one of the microphone and the piezoelectric speaker as a signal source for incident sound based on the at least one characteristic.

A MEMS microphone is provided, comprising a substrate having a back cavity, and a plate capacitor structure arranged on the substrate, the plate capacitor structure being formed by a vibration diaphragm, a backplate and a support portion; wherein a pressure relief device is provided in the vibration diaphragm, a pressure maintaining channel is formed between the vibration diaphragm and the backplate; and the pressure relief device in the vibration diaphragm constitutes an inlet of the pressure maintaining channel.

A MEMS microphone is provided, comprising a substrate having a back cavity, and a plate capacitor structure arranged on the substrate, the plate capacitor structure being formed by a vibration diaphragm, a backplate and a support portion; wherein a pressure relief device is provided in the vibration diaphragm, a pressure maintaining channel is formed between the vibration diaphragm and the backplate; and the pressure relief device in the vibration diaphragm constitutes an inlet of the pressure maintaining channel.

A MEMS device includes a first multi-layer structure, a second multi-layer structure over the first multi-layer structure, a first semiconductor layer between the first and second multilayer structures, a first air gap separating the first multi-layer structure and the first semiconductor layer, a second air gap separating the first semiconductor layer and the second multi-layer structure, a plurality of semiconductor pillars, and a plurality of second semiconductor pillars. The first semiconductor pillars are exposed to the first air gap, and coupled to the first semiconductor layer and the first multi-layer structure. The second semiconductor pillars are exposed to the second air gap, and coupled to the first semiconductor layer and the second multi-layer structure.

A sensor device includes an electrically conductive base substrate defining a first electrode kept at a reference potential, a membrane defining a second electrode that changes a position thereof in response to a change of surrounding pressure and faces the base substrate, a casing that is kept at the reference potential and is outside the membrane, a capacitance detection circuit to amplify a signal from the membrane and detect an electrostatic capacitance between electrodes at a predetermined sampling cycle, and a signal processing circuit to measure a difference ΔC of electrostatic capacitance values before and after a sampling, compare the difference AC with a predetermined threshold value Cta, and when ΔC≥Cta, determine that a foreign object is attached to the casing. Thus, the attachment of a foreign object can be reliably detected.

A MEMS microphone includes a substrate, a connecting base, and a capacitance system. Connecting ports are formed on the connecting base, where the at least two connecting ports are recessed outwards from an inner wall of the connecting base and are disposed at intervals. The capacitance system includes a system main body and connecting pins. A system main body of the capacitance system is fixed to the connecting ports of the connecting base through the connecting pins. In addition, the slit is formed between the outer side of the system main body and the inner wall of the connecting base, the capacitance system is stably and reliably assembled in the connecting base through a connecting structure where the connecting pins are matched with the connecting ports, and compliance of vibration of the system main body of the capacitance system is increased through matching the connecting pins with slit.

A MEMS microphone includes a substrate, a connecting base, and a capacitance system. Connecting ports are formed on the connecting base, where the at least two connecting ports are recessed outwards from an inner wall of the connecting base and are disposed at intervals. The capacitance system includes a system main body and connecting pins. A system main body of the capacitance system is fixed to the connecting ports of the connecting base through the connecting pins. In addition, the slit is formed between the outer side of the system main body and the inner wall of the connecting base, the capacitance system is stably and reliably assembled in the connecting base through a connecting structure where the connecting pins are matched with the connecting ports, and compliance of vibration of the system main body of the capacitance system is increased through matching the connecting pins with slit.

A MEMS microphone includes a substrate, a base, a capacitance system, and at least one cantilever structure. The substrate includes a back cavity, the base is disposed on one side of the substrate, and the capacitance system is disposed on the base. The capacitance system includes at least one back plate assembly, at least one first vibration diaphragm, and at least one second vibration diaphragm. The at least one first vibration diaphragm includes a first sub-vibration diaphragm, and the at least one second vibration diaphragm includes a second sub-vibration diaphragm. The sub-vibration diaphragm and the second sub-vibration diaphragm form a cantilever beam structure on the base, which increase compliance of the at least one first vibration diaphragm and the at least one second vibration diaphragm and reduce tension of the at least one first vibration diaphragm and the at least one second vibration diaphragm, thereby improving sensitivity of the microphones.

A MEMS microphone includes a substrate, a base, a capacitance system, and at least one cantilever structure. The substrate includes a back cavity, the base is disposed on one side of the substrate, and the capacitance system is disposed on the base. The capacitance system includes at least one back plate assembly, at least one first vibration diaphragm, and at least one second vibration diaphragm. The at least one first vibration diaphragm includes a first sub-vibration diaphragm, and the at least one second vibration diaphragm includes a second sub-vibration diaphragm. The sub-vibration diaphragm and the second sub-vibration diaphragm form a cantilever beam structure on the base, which increase compliance of the at least one first vibration diaphragm and the at least one second vibration diaphragm and reduce tension of the at least one first vibration diaphragm and the at least one second vibration diaphragm, thereby improving sensitivity of the microphones.