One of the main objects of the present invention is to provide a MEMS acoustic sensor with improved acoustic performance and liability. To achieve the above-mentioned objects, the present invention provides a MEMS acoustic sensor, including: a base with a cavity; a number of structural layers fixed on the base, each including a fixed end fixed to the base and a suspension end extending from the fixed end for being suspended above the cavity, the suspension end being spaced from the base for forming a slit; a piezoelectric functional layer on the suspension end; and a flexible connector completely covering the slit; wherein a Young's modulus of the flexible connector is smaller than a Young's modulus of the structural layer.

Provided are an electroacoustic transduction film capable of reproducing a sound with a sufficient sound volume at a high conversion efficiency, a manufacturing method thereof, an electroacoustic transducer, a flexible display, a vocal cord microphone, and a sensor for a musical instrument. The electroacoustic transduction film includes: a polymer composite piezoelectric body in which piezoelectric body particles are dispersed in a viscoelastic matrix formed of a polymer material having viscoelasticity at a normal temperature; two thin film electrodes laminated on both surfaces of the polymer composite piezoelectric body; and two protective layers respectively laminated on the two thin film electrodes, in which an intensity ratio α.sub.1=(002) plane peak intensity/((002) plane peak intensity+(200) plane peak intensity) between a (002) plane peak intensity and a (200) plane peak intensity derived from the piezoelectric body particles in a case where the polymer composite piezoelectric body is evaluated by an X-ray diffraction method is more than or equal to 0.6 and less than 1.

Provided are an electroacoustic transduction film capable of reproducing a sound with a sufficient sound volume at a high conversion efficiency, a manufacturing method thereof, an electroacoustic transducer, a flexible display, a vocal cord microphone, and a sensor for a musical instrument. The electroacoustic transduction film includes: a polymer composite piezoelectric body in which piezoelectric body particles are dispersed in a viscoelastic matrix formed of a polymer material having viscoelasticity at a normal temperature; two thin film electrodes laminated on both surfaces of the polymer composite piezoelectric body; and two protective layers respectively laminated on the two thin film electrodes, in which an intensity ratio α.sub.1=(002) plane peak intensity/((002) plane peak intensity+(200) plane peak intensity) between a (002) plane peak intensity and a (200) plane peak intensity derived from the piezoelectric body particles in a case where the polymer composite piezoelectric body is evaluated by an X-ray diffraction method is more than or equal to 0.6 and less than 1.

Provided are a directional acoustic sensor that detects a direction of sound, a method of detecting a direction of sound, and an electronic device including the directional acoustic sensor. The directional acoustic sensor includes a sound inlet through which a sound is received, a sound outlet through which the sound received through the sound inlet is output, and a plurality of vibration bodies arranged between the sound inlet and the sound outlet, in which one or more of the plurality of vibration bodies selectively react to the sound received by the sound inlet according to a direction of the received sound.

Provided are a directional acoustic sensor that detects a direction of sound, a method of detecting a direction of sound, and an electronic device including the directional acoustic sensor. The directional acoustic sensor includes a sound inlet through which a sound is received, a sound outlet through which the sound received through the sound inlet is output, and a plurality of vibration bodies arranged between the sound inlet and the sound outlet, in which one or more of the plurality of vibration bodies selectively react to the sound received by the sound inlet according to a direction of the received sound.

A target tracking system and method of operation can include: generating data based on a detection of a shock wave of a bullet by target microphones, the target microphones including an offset target microphone; wirelessly transmitting the data with a target transceiver communicatively connected to the target microphones; determining a bullet speed at the target microphones based on the shock wave detected by the offset target microphone with a processor; and determining a shot placement of the bullet relative to the target microphones with the processor, the processor communicatively connected to the target transceiver.

An acoustic sensor (e.g., for use in a piezoelectric MEMS microphone) includes a substrate and a cantilever beam attached to the substrate. The cantilever beam has a proximal portion attached to the substrate and extends to a distal tip at a free end thereof. The cantilevered beam has a multilayer structure with a plurality of piezoelectric layers and a plurality of metal electrode layers, at least a portion of one of the piezoelectric layers interposed between two metal electrode layers. One or more direct current voltage sources are electrically connected to one or more of the plurality of metal electrode layers and configured to apply a direct current bias voltage between at least two of the plurality of metal electrode layers to deflect the cantilever beam to at least partially counteract a deflection of the cantilever beam due to a residual stress in the cantilever beam.

An acoustic sensor (e.g., for use in a piezoelectric MEMS microphone) includes a substrate and a cantilever beam attached to the substrate. The cantilever beam has a proximal portion attached to the substrate and extends to a distal tip at a free end thereof. The cantilevered beam has a multilayer structure with a plurality of piezoelectric layers and a plurality of metal electrode layers, at least a portion of one of the piezoelectric layers interposed between two metal electrode layers. One or more direct current voltage sources are electrically connected to one or more of the plurality of metal electrode layers and configured to apply a direct current bias voltage between at least two of the plurality of metal electrode layers to deflect the cantilever beam to at least partially counteract a deflection of the cantilever beam due to a residual stress in the cantilever beam.

A microelectromechanical systems device includes a vibrator and a reinforcing film. The vibrator includes a piezoelectric element configured to convert pressure to an electrical signal. The reinforcing film is configured to reinforce strength of the vibrator. The vibrator further has a groove at which a portion of the reinforcing film is disposed.

A microelectromechanical systems device includes a vibrator and a reinforcing film. The vibrator includes a piezoelectric element configured to convert pressure to an electrical signal. The reinforcing film is configured to reinforce strength of the vibrator. The vibrator further has a groove at which a portion of the reinforcing film is disposed.