A multi-layer piezoelectric microactuator assembly has at least one poled and active piezoelectric layer and one poled but inactive piezoelectric layer. The poled but inactive layer acts as a constraining layer in resisting expansion or contract of the first piezoelectric layer thereby reducing or eliminating bending of the assembly as installed in an environment, thereby increasing the effective stroke length of the assembly. Poling only a single layer would induce stresses into the device; hence, polling both piezoelectric layers even though only one layer will be active in use reduces stresses in the device and therefore increases reliability.

A piezoelectric transformer that includes a vibration portion assembly having an output electrode, an output-side intermediate electrode, an input-side intermediate electrode, and an input electrode. The vibration portion assembly includes n vibration portions. The input electrode includes one to n input electrode pieces. The output electrode includes one to n output electrode pieces. Wiring lines are arranged such that voltages of opposite phases can be respectively applied to a first input electrode piece group of the input electrode pieces corresponding to odd-numbered vibration portions, and a second input electrode piece group of the input electrode pieces corresponding to even-numbered vibration portions. The second output electrode piece and the first output-side intermediate electrode piece are superposed with each other in the thickness direction. The first output electrode piece is not superposed with either of the first and second output-side intermediate electrode pieces in the thickness direction.

The present invention provides an ultrasonic fingerprint recognition module and a display panel. Advantages of the present invention are that a vibration absorbing layer can absorb mechanical energy of a piezoelectric thin film layer such that a number of cycles of later ultrasound is significantly reduces to extremely increase a vertical resolution of ultrasound fingerprint recognition and overall recognition effect and precision.

A piezoelectric device and a fabricating method thereof, and an electronic device and a controlling method thereof, which relates to the technical field of piezoelectric devices. The piezoelectric device includes: a flexible substrate and a plurality of piezoelectric units that are provided on the flexible substrate and are arranged in an array; each of the plurality of piezoelectric units includes: a first electrode, a piezoelectric component and a second electrode that are sequentially stacked on the flexible substrate; and the piezoelectric component is made from a rigid material. The present disclosure is suitable for the fabrication of piezoelectric devices.

An object is to provide a piezoelectric film that has excellent flexibility in a high temperature environment at higher than 50° C. and exhibits good flexibility even at room temperature, a laminated piezoelectric element in which the piezoelectric films are laminated, and an electroacoustic transducer using the piezoelectric film or the laminated piezoelectric element. The object is solved by the piezoelectric film including: a polymer-based piezoelectric composite material in which piezoelectric particles are dispersed in a matrix including a polymer material; and electrode layers provided on both surfaces of the polymer-based piezoelectric composite material, in which a loss tangent at a frequency of 1 Hz according to dynamic viscoelasticity measurement has a maximal value of greater than or equal to 0.1 existing in a temperature range of higher than 50° C. and lower than or equal to 150° C., and has a value of greater than or equal to 0.08 at 50° C.

An object is to provide a piezoelectric film that has excellent flexibility in a sub-zero environment and exhibits the required flexibility even at room temperature, a laminated piezoelectric element in which the piezoelectric films are laminated, and an electroacoustic transducer using the piezoelectric film or the laminated piezoelectric element. The object is solved by the piezoelectric film including: a polymer-based piezoelectric composite material in which piezoelectric particles are dispersed in a matrix including a polymer material; and electrode layers formed on both surfaces of the polymer-based piezoelectric composite material, in which a loss tangent at a frequency of 1 Hz according to dynamic viscoelasticity measurement has a maximal value of greater than or equal to 0.1 existing in a temperature range of higher than or equal to −80° C. and lower than 0° C., and has a value of greater than or equal to 0.05 at 0° C.

Activity of piezoelectric material dimension and electrical properties can be changed with an applied stress. These variations are translated to a change in capacitance of the structure. Use of capacitance-voltage measurements for the extraction of double piezoelectric thin film material deposited at the two faces of a flexible steel sheet is described. Piezoelectric thin film materials are deposited using RF sputtering techniques. Gamry analyzer references 3000 is used to collect the capacitance-voltage measurements from both layers. A developed algorithm extracts directly the piezoelectric coefficients knowing film thickness, applied voltage, and capacitance ratio. The capacitance ratio is the ratio between the capacitances of the film when the applied field in antiparallel and parallel to the poling field direction, respectively. Piezoelectric bulk ceramic is used for calibration and validation by comparing the result with the reported values from literature. Extracted values using the current approach match well values extracted by existing methods.

A method for monitoring polarization quality of a piezoelectric film is described. In this method, a detection step is performed on a piezoelectric film by using a detection device with a non-contact method during a polarization process of the piezoelectric film, to obtain a static electricity information or a transmittance information. A determination step is performed by using the static electricity information or the transmittance information to determine a polarization degree of the piezoelectric film.

A piezoelectric transducer (100) comprises a piezoelectric foil (10) with a piezoelectric material (M) exhibiting a shear piezoelectric effect (d14). An actuating structure (20) is configured to actuate the foil with actuation forces (Fu, Fd) applied at respective actuation points (Au, Ad) in respective actuation directions (U, D) to bend the foil in two opposing bending directions (S1, S2), which are orthogonal to each other and both diagonal to the polarization direction (3) of the foil, according to a saddle shape deformation. Preferably, the foil (10) is wrapped around a flexible plate (15).

A method for manufacturing a piezoelectric film deposition substrate (100) according to this present invention includes forming a piezoelectric film (3) on or above the lower electrode (2) with the mask (5) being attached on or above the lower electrode; forming an upper electrode (4) on the piezoelectric film with the mask being attached on or above the lower electrode; forming a the lower-electrode-exposed part (2a) by detaching the mask from the lower electrode; and subjecting the piezoelectric film to polarization by applying a voltage between the lower-electrode-exposed part and the upper electrode.