A piezoelectric microelectromechanical systems device can include a cavity bounded by walls and an asymmetrical bimorph structure at least partially spanning the cavity that includes at least a piezoelectric layer and two electrode layers. The electrode layers can have relative thicknesses configured to compensate for expected temperature stress in the bimorph structure. Thus, metals having different thicknesses can be positioned and configured to compensate deflection due to thermal stress of any or all of the piezoelectric layer, the first metal layer, and second metal layer and a substrate. A method for making the piezoelectric microelectromechanical systems device is also provided.

A piezoelectric microelectromechanical systems device can include a cavity bounded by walls and an asymmetrical bimorph structure at least partially spanning the cavity that includes at least a piezoelectric layer and two electrode layers. The electrode layers can have relative thicknesses configured to compensate for expected temperature stress in the bimorph structure. Thus, metals having different thicknesses can be positioned and configured to compensate deflection due to thermal stress of any or all of the piezoelectric layer, the first metal layer, and second metal layer and a substrate. A method for making the piezoelectric microelectromechanical systems device is also provided.

The present disclosure relates generally to providing a flexible patch and system for communicating through hard plastic masks such as CPAP/BiPAP® masks. Using electronic circuitry and novel designs, the present systems and methods can detect speech vibrations and output audible speech from hard plastic mask wearers. For example, in certain embodiments, the present systems and methods can recognize speech through a CPAP/BiPAP® mask, filter out non-human voice related noise, and output the resulting speech of the mask wearer.

The present disclosure relates generally to providing a flexible patch and system for communicating through hard plastic masks such as CPAP/BiPAP® masks. Using electronic circuitry and novel designs, the present systems and methods can detect speech vibrations and output audible speech from hard plastic mask wearers. For example, in certain embodiments, the present systems and methods can recognize speech through a CPAP/BiPAP® mask, filter out non-human voice related noise, and output the resulting speech of the mask wearer.

A piezoelectric microelectromechanical systems diaphragm microphone can be mounted on a printed circuit board. The microphone can include a substrate with an opening between a bottom end of the substrate and a top end of the substrate. The microphone can have two or more piezoelectric film layers disposed over the top end of the substrate and defining a diaphragm structure. Each of the two or more piezoelectric film layers can have a predefined residual stress that substantially cancel each other out so that the diaphragm structure is substantially flat with substantially zero residual stress. The microphone can include one or more electrodes disposed over the diaphragm structure. The diaphragm structure is configured to deflect when the diaphragm is subjected to sound pressure via the opening in the substrate.

A piezoelectric microelectromechanical systems diaphragm microphone can be mounted on a printed circuit board. The microphone can include a substrate with an opening between a bottom end of the substrate and a top end of the substrate. The microphone can have two or more piezoelectric film layers disposed over the top end of the substrate and defining a diaphragm structure. Each of the two or more piezoelectric film layers can have a predefined residual stress that substantially cancel each other out so that the diaphragm structure is substantially flat with substantially zero residual stress. The microphone can include one or more electrodes disposed over the diaphragm structure. The diaphragm structure is configured to deflect when the diaphragm is subjected to sound pressure via the opening in the substrate.

A piezoelectric microelectromechanical system microphone comprises a piezoelectric element configured to deform and generate an electrical potential responsive to impingement of sound waves on the piezoelectric microelectromechanical system microphone, a sensing electrode disposed on the piezoelectric element and configured to sense the electrical potential, and a passive membrane mechanically coupled to the surface of the piezoelectric element to increase sensitivity of the piezoelectric microelectromechanical system microphone.

A piezoelectric microelectromechanical system microphone comprises a piezoelectric element configured to deform and generate an electrical potential responsive to impingement of sound waves on the piezoelectric microelectromechanical system microphone, a sensing electrode disposed on the piezoelectric element and configured to sense the electrical potential, and a passive membrane mechanically coupled to the surface of the piezoelectric element to increase sensitivity of the piezoelectric microelectromechanical system microphone.

A compact directional acoustic sensor having an improved signal-to-noise ratio is disclosed. The disclosed directional acoustic sensor includes a first sensing device configured to generate different output gains based on different input directions of external energy, and configured to generate at least one first output signal having a first polarity based on external energy received from an input direction; a second sensing device configured to generate different output gains based on different input directions of external energy, and configured to generate at least one second output signal having a second polarity, that is different than the first polarity, based on the external energy received from the input direction; and at least one signal processor configured to generate at least one final output signal based on the at least one first output signal and the at least one second output signal.

An interactive system can utilize microtechnology (e.g., a micro-electromechanical system (MEMS)), such as miniaturized microphone (e.g., a bone-conducting microphone), audio output device, microprocessor, and signal conversion and propagation means to create a personal area network (PAN) for a user. The system can include a voice input device (e.g., worn on one or more teeth of the user) that outputs a near-field magnetic induction (NFMI) signal based on a whisper input by the user. The NFMI signal is either detected by the user's mobile device, or converted into a wireless signal (e.g., a Bluetooth RF signal) detectable by the user's mobile device, for receiving voice commands (e.g., to provide personal assistant services) via a designated application running on the mobile device.