A piezoelectric device has a layered structure in which at least a first electrode, a plastic layer, an orientation control layer, a piezoelectric layer, and a second electrode are stacked, wherein the orientation control layer is amorphous, and the piezoelectric layer with a thickness of 20 nm to 250 nm is provided over the orientation control layer, the piezoelectric layer having a wurtzite crystal structure, and wherein the orientation control layer and the piezoelectric layer are provided between the first electrode and the second electrode.

A piezoelectric device has a layered structure in which at least a first electrode, a plastic layer, an orientation control layer, a piezoelectric layer, and a second electrode are stacked, wherein the orientation control layer is amorphous, and the piezoelectric layer with a thickness of 20 nm to 250 nm is provided over the orientation control layer, the piezoelectric layer having a wurtzite crystal structure, and wherein the orientation control layer and the piezoelectric layer are provided between the first electrode and the second electrode.

An electric current based on electric charge produced on the piezoelectric body changes by going through a first path, a second path, a third path, and a fourth path in this order. On the first path, the electric current becomes larger as the voltage becomes higher. On the second path, the electric current becomes smaller as the voltage becomes higher. On the third path, the electric current becomes larger as the voltage becomes higher. On the fourth path, the electric current becomes smaller as the voltage becomes higher.

Disclosed is electromechanical actuator for ultrasonic motor in the shape of an n-sided regular polygon plate with n being equal to or greater than five. The polygon plate has two larger main surfaces and at least five smaller side surfaces connecting the main surfaces with each other. Two electrodes are arranged on one of the main surfaces and are electrically isolated from each other by a linear isolation area. One electrode is arranged on the other of the main surfaces. The polygon plate comprises an electromechanical material that undergoes a deformation when electric voltage is applied to the electrodes. The material of the electromechanical actuator comprises a single or polycrystalline piezoelectric ceramic with piezoelectric charge constant d31 differing from piezoelectric charge constant d32 both in sign and in value. The piezoelectric charge constants d31 and d32 define a first and second main deformation direction of the actuator perpendicular to each other. The orientation of the linear isolation area is parallel to either deformation direction.

A piezoelectric composition comprises an oxide having a perovskite structure, wherein the oxide contains bismuth, barium, iron and titanium; the X-ray diffraction pattern of the piezoelectric composition after a polarization treatment has a first peak and a second peak in the range of the diffraction angle 2θ of 38.6° or more and 39.6° or less; the diffraction angle 2θ of the first peak is smaller than the diffraction angle 2θ of the second peak; an intensity of the first peak is represented as I.sub.L; an intensity of the second peak is represented as I.sub.H; and I.sub.H/I.sub.L is 0.00 or more and 2.00 or less.

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.

A piezoelectric device including a substrate, a metal-insulator-metal element, a hydrogen blocking layer, a passivation layer, a first contact terminal and a second contact terminal is provided. The metal-insulator-metal element is disposed on the substrate. The hydrogen blocking layer is disposed on the metal-insulator-metal element. The passivation layer covers the hydrogen blocking layer and the metal-insulator-metal element. The first contact terminal is electrically connected to the metal-insulator-metal element. The second contact terminal is electrically connected to the metal-insulator-metal element.

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.

Proposed is a method of manufacturing a piezoelectric composite material. The method includes the steps: wet mixing the ceramic powder, the polymer binder, the plasticizer, and the solvent for 4 to 72 hours to produce the mixed slurry, in which the amount of the polymer binder in the mixed slurry is 3 to 10 parts by weight, the amount of the plasticizer is 0.1 to 3 parts by weight, and the amount of the solvent is 30 or more to less than 50 parts by weight, based on 100 parts by weight of the ceramic powder in the mixed slurry; introducing the mixed slurry into a tape casting process to produce a piezoelectric composite sheet; drying and molding the piezoelectric composite sheet in a roll-to-roll process to form a molded piezoelectric composite sheet; laminating and compressing piezoelectric composite sheets molded to produce piezoelectric composite sheet laminates; and cutting the piezoelectric composite sheet laminate into the desired shape and size.

Various systems, devices, and methods for a vehicle smart brake pad comprising a sensor such as a force sensing device, and a production process thereof. For example, a production process of a vehicle brake pad can include the following steps in time sequence: applying an electrical circuit a support plate; screen printing on the electrical circuit of at least a first electrode; screen printing on the at least first electrode of a sheet of piezoelectric material; screen printing on the sheet of at least a second electrode; applying a friction pad on the support plate; and bulk polarizing the sheet of piezoelectric material by a supply of power to the at least first and second electrodes.