A method of making an acoustic sensor (e.g., a piezoelectric sensor for a piezoelectric microelectromechanical systems microphone) includes forming or depositing one or more piezoelectric layers to define a beam extending between a proximal portion and a distal tip (e.g., unsupported free end), the beam having a width in plan view that is greater at a location distal of the proximal portion than at the proximal portion. The method also comprises attaching the beam to a substrate in cantilever form so that the proximal portion of the beam is anchored to the substrate and the distal tip is a free unsupported end of the beam. One or more electrodes are disposed on or in the proximal portion of the beam.

An ultrasonic sensor includes an element substrate having a first and a second surface at an opposite side of the first surface, including an opening section piercing through the element substrate in a Z direction from the first to second surface, a vibrating plate on the first surface of the element substrate to close the opening section, a plurality of vibration regions extending along an X direction orthogonal to the Z direction on the vibration plate in positions overlapping the opening section, and a plurality of piezoelectric elements to correspond to the plurality of vibration regions of the vibration plate. The opening section includes, on the first surface, a first and second side parallel to the X direction and a third and fourth side coupling end portions in the X direction of the first and second sides at an acute or obtuse angle to the first and the second side.

A piezoelectric thin film 3 contains a metal oxide, the metal oxide contains bismuth, potassium, titanium, iron and element M, the element M is at least one of magnesium and nickel, at least a part of the metal oxide is a crystal having a perovskite structure, and a (001) plane, a (110) plane or a (111) plane of the crystal is oriented in a normal direction dn of the surface of the piezoelectric thin film 3.

A touch-sensitive assembly and method of making includes a first electrically conductive layer disposed on a first substrate and a second electrically conductive layer disposed on a second substrate. A piezoelectric film is disposed between the first electrically conductive layer and the second electrically conductive layer. The piezoelectric film includes a plurality of aligned piezoelectric particles disposed in a polymeric matrix and is characterized by a haze value of about 5% or less.

A display device that senses externally applied pressure and a change in the resonant frequency of a piezoelectric element. The display device includes a piezoelectric sensor layer including a piezoelectric sensor; and a display panel disposed on the piezoelectric sensor layer. The piezoelectric sensor includes: a piezoelectric element having a first electrode, a second electrode facing the first electrode, and a piezoelectric material disposed between the first electrode and the second electrode; an alternating current (AC) voltage generator connected to the first electrode and applies a voltage having a resonance frequency to the piezoelectric element. A sensing circuit connected to the second electrode is configured to measure a change in impedance of the piezoelectric element.

A normal-temperature heat engine power generation device based on a drinking bird is provided. The device includes a drinking bird body, a piezoelectric module and an electromagnetic module. The piezoelectric module includes a cantilever beam, a piezoelectric sheet arranged on the cantilever beam and working loads arranged at an end of the cantilever beam. when a head of the drinking bird body swings downwards, a tip of a beak can impact the working loads. The electromagnetic module includes magnets, coils and coil magnet conducting columns. The magnets are arranged at a bottom of a spherical bottom of the drinking bird body, and the coil magnet conducting columns sleeving the coils are arranged on a base of the drinking bird body.

An ultrasonic sensor includes a piezoelectric body including first and second surfaces. First and second electrodes are respectively provided on the first and second surfaces. The second electrode is opposed to the first electrode with the piezoelectric body interposed therebetween. A third electrode is provided on the second surface. The third electrode is spaced apart from the second electrode. The third electrode is electrically connected to the first electrode. When viewed from a thickness direction in which the first surface and the second surface are arranged, the second electrode extends to both end edges of the second surface in a first direction and is spaced apart from both end edges of the second surface in a second direction orthogonal to the first direction.

A microphone with an additional piezoelectric component for energy harvesting is provided, and includes a substrate penetrated through by a cavity, a diaphragm, and a piezoelectric conversion. The diaphragm includes a vibration portion and at least one connecting arm, and two ends of each of the at least one connecting arm are connected to the vibration portion and the substrate, respectively. The piezoelectric conversion component is disposed on one of the at least one connecting arm and configured to convert mechanical energy collected from a displacement of the diaphragm by sound to electrical energy. The piezoelectric conversion component is mounted on the diaphragm, so as to convert the mechanical energy collected from the diaphragm by the sound to the electrical energy, thereby effectively recycling the mechanical energy and avoiding a waste of energy.

A stretchable temperature sensor includes one or more elastomeric ionic conducting layers; at least two electronic conducting elements, wherein the one or more ionic conducting layers and one or more electronic conducting elements are configured and arranged to provide at least one electrical double layer at a first contact area between the ionic conducting layer and a first electronic conducting element in a sensing end and at least one electrical double layer at a contact area between the ionic conducting layer and a second electronic conducting element in an open end of the temperature sensor; wherein the second electronic conducting element provides a connection at the open end to an external circuit for measuring a signal generated in response to a temperature condition at the sensing end.

An ultrasonic fingerprint recognition sensor and a manufacturing method thereof, and a display device are disclosed. The ultrasonic fingerprint recognition sensor includes a resonant cavity, a receiver electrode, a drive electrode, and a piezoelectric thin film layer between the receiver electrode and the drive electrode, the resonant cavity is on a side, closer to the piezoelectric thin film layer, of the receiver electrode, and is configured to increase vibration amplitude of the piezoelectric thin film layer.