A power generator includes an electret including a first charged surface and a second charged surface having opposite polarities, a first electrode partially formed on the first charged surface, a second electrode formed on the second charged surface, a third electrode disposed to face the first charged surface with a space, and at least one of a power storage unit or an output unit. The first charged surface has a current collecting surface that is exposed outward. The first electrode and the second electrode form a first power generating unit and the third electrode and the second electrode form a second power generating unit. The electret is formed by polarizing an electret material that includes an inorganic dielectric having a bandgap energy of 4 eV or more.

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.

Provided is an energy conversion film excellent in charge retention performance and suppressed in deterioration of piezoelectricity even if it is exposed to a high temperature environment and an energy conversion element and the like using the film. An energy conversion element comprising: an energy conversion film at least comprises a charged resin film consisting of a resin film at least containing a thermoplastic resin and a metal soap; and an electrode provided on at least one of the two surfaces of the energy conversion film.

The invention relates to a piezoelectric energy harvesting system (10) configured to be installed on a vehicle (1), characterized in that the system (10) comprises: —an inner panel (12); —an outer panel (14) slidably movable relative to the inner panel (12); —at least one deformable piezoelectric element (16) disposed between the inner panel (12) and the outer panel (14), said piezoelectric element (16) being capable of producing electrical power when it is deformed; —a plurality of impact elements (18) fixedly connected to the outer panel (14) and adapted to apply a compression force on the at least one piezoelectric element (16) when the outer panel (14) and the inner panel (12) are close enough to each other, said compression force causing a mechanical deformation of the at least one piezoelectric element (16); —repulsion means (22) adapted to move the outer panel (14) away from the inner panel (12); —an electrical power storage unit (24); —a one-way electrical circuit (26) connecting the at least one piezoelectric element (16) to the electrical power storage unit (24), said one-way electrical circuit (26) being adapted to charge the electrical power storage unit (24) with the electrical power produced by the at least one piezoelectric element (16) while preventing the application of an electrical charge to the at least one piezoelectric element (16) from the electrical power storage unit (24).

Piezo-optic transducers convert variations in mechanical stress to a change in optical properties by coupling electro-optic and piezo-electric elements in a format suited to a single composite device without needing on-board electronics.

A piezoelectric element drive circuit includes a piezoelectric element driven at a predetermined frequency and having a resonant frequency of (2n+1) times the predetermined frequency (n is a predetermined natural number), and a drive voltage generator that has a first output terminal connected to a first terminal of the piezoelectric element and a second output terminal connected to a second terminal of the piezoelectric element. When the piezoelectric element is driven, a waveform of potential difference between the first output terminal and the second output terminal is a step wave which transitions while taking an intermediate potential. A time length for which the potential difference is the intermediate potential is around (t2−t1)/(2n+1) in a period of time from time t.sub.1 at which the potential difference falls to the intermediate potential to time t.sub.2 at which the potential difference falls to the intermediate potential subsequently.

An acoustic transducer, in particular for an ultrasonic sensor, is proposed. The acoustic transducer has a functional group, the functional group encompassing a diaphragm cup and at least one electroacoustic transducer element. The acoustic transducer furthermore has a housing. The diaphragm cup encompasses a vibration-capable diaphragm and an encircling wall, as well as at least one electroacoustic transducer element, the transducer element being embodied to excite the diaphragm to vibrate and/or to convert vibrations of the diaphragm into electrical signals. The diaphragm cup is constituted from a plastic material, the at least one transducer element being integrated into the vibration-capable diaphragm, the transducer element having an electrically active polymer.

Disclosed herein is an ultrasonic probe including a piezoelectric layer, a matching layer disposed at an upper portion of the piezoelectric layer, a conductive member disposed at a lower portion of the piezoelectric layer, a second connector coupled to at least one side of the conductive member, and a printed circuit board coupled to a side of the second connector and electrically coupled to the second connector. A printed circuit board is disposed outside a laminated structure of the acoustic element so that the printed circuit board can be prevented from affecting acoustic characteristics of the ultrasonic probe, a failure in a process of manufacturing the ultrasonic probe that occurs due to a change in temperature or humidity can be prevented, and the manufacturing process can be relatively simplified.

A piezoelectric component that has a piezoelectric element including a piezoelectric ceramic layer and a sintered metal layer on at least a first main surface of the piezoelectric ceramic layer and containing a non-precious metal, and a protective layer containing an elastic body covering first and second opposed main surfaces of the piezoelectric element. The piezoelectric ceramic layer contains 90 mol % or more of a perovskite compound that contains niobium, an alkali metal, and oxygen. A thickness of the piezoelectric element is 100 μm or less.

An energy conversion device for conversion of various energy forms into electricity. The energy forms may be chemical, photovoltaic or thermal gradients. The energy conversion device has a first and second electrode. A substrate is present that has a porous semiconductor or dielectric layer placed thereover. The substrate itself can be planar, two-dimensional, or three-dimensional, and possess internal and external surfaces. These substrates may be rigid, flexible and/or foldable. The porous semiconductor or dielectric layer can be a nano-engineered structure. A porous conductor material is placed on at least a portion of the porous semiconductor or dielectric layer such that at least some of the porous conductor material enters the nano-engineered structure of the porous semiconductor or dielectric layer, thereby forming an intertwining region.