A copolymer including fluorinated units of formula (I):

—CX.sub.1X.sub.2—CX.sub.3X.sub.4—  (I) in which each of the X.sub.1, X.sub.2, X.sub.3 and X.sub.4 is independently chosen from H, F and alkyl groups including from 1 to 3 carbon atoms which are optionally partially or totally fluorinated; and units of formula (III):

—CX.sub.AX.sub.B—CX.sub.CZ—  (III) in which each of the X.sub.A, X.sub.B and X.sub.C is independently chosen from H, F and alkyl groups including from 1 to 3 carbon atoms which are optionally partially or totally fluorinated, and Z being a polarizable group of formula —Y—Ar—R; Y representing an O atom or an S atom or an NH group, Ar representing an aryl group, and R being a monodentate or bidentate group including from 1 to 30 carbon atoms; and the copolymer having a heat of fusion of greater than or equal to 5 J/g. Also a process, a composition, an ink and a film.

The present invention relates to a piezoelectric material, comprising: a vinylidene fluoride/trifluoroethylene copolymer; and a (meth)acrylic polymer which contains a structural unit derived from a (meth)acrylic monomer represented by Formula (I):

##STR00001## [wherein, R.sub.1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, wherein at least one hydrogen atom of R.sub.1 is optionally substituted with a halogen atom; and R.sub.2 represents a linear or branched alkyl group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms which contains an alicyclic structure having 3 to 6 carbon atoms, a phenyl group, or a phenylalkylene group which contains an alkylene group having 1 to 4 carbon atoms, wherein, at least one carbon atom of the alkyl group, the alicyclic hydrocarbon group, the phenyl group, and the phenylalkylene group is optionally substituted with —O—, —N—, or —S—, at least one hydrogen atom of the alkyl group, the alicyclic hydrocarbon group, and the alkylene group is optionally substituted with a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and/or an alkoxy group having 1 to 6 carbon atoms, at least one hydrogen atom on the phenyl rings of the phenyl group and the phenylalkylene group is optionally substituted with a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and/or a cyano group, and at least one hydrogen atom of R.sub.2 is optionally substituted with a halogen atom, with a proviso that at least one hydrogen atom of R.sub.1 and/or R.sub.2 is substituted with a halogen atom.

An ultrasonic fingerprint recognition assembly is provided. The ultrasonic fingerprint recognition assembly includes a cover plate, a display panel, and an ultrasonic sensor disposed between the cover plate and the display panel. The ultrasonic sensor includes a thin film transistor (TFT) substrate which is close to the display panel, and a piezoelectric layer and a conductive layer which are disposed on the TFT substrate sequentially. The piezoelectric layer is obtained by mixing a piezoelectric material with an organic solvent, coating a mixture of the piezoelectric material and the organic solvent on a substrate, and conducting crystallization and polarization treatment. The organic solvent includes at least one of: butanone, propylene glycol monomethyl ether acetate, and dimethylacetamide.

According to one embodiment, a pressure sensor includes an insulating base material, an switching element disposed on the insulating base material, a piezoelectric layer disposed on the insulating base material and the switching element and an underlying layer located between the piezoelectric layer and the insulating base material, and the modulus of elasticity of the underlying layer is greater than the modulus of elasticity of the piezoelectric layer.

The present invention relates to a method of preparing a shape-reconfigurable micropatterned polymer haptic material using an electric field technique, and more particularly, to a method of preparing a shape-reconfigurable micro-patterned polymer thin film and a haptic material by controlling the orientation of a liquid-crystalline organic polymer using an electric field control system and inducing the generation of defect structures having a regular microstructure array in a polymer film.

A piezoelectric polyvinylidene fluoride (PVDF) material, a method for manufacturing the same, and a fingerprint recognition module are provided. The polyvinylidene PVDF material includes PVDF, a first solvent, a second solvent, a fluorosurfactant, and an inducing material. Material of the inducing material is one of carbon nanotubes, carbon black, and gold nanorods. Because of the high anisotropy of the inducing material, molecular orientation of the PVDF material is induced, thereby improving piezoelectric performance of the piezoelectric PVDF material. Problems of conventional piezoelectric PVDF materials, which are used in ultrasonic fingerprint recognition modules, such as poor piezoelectric performance and high-energy loss are improved.

Proposed is a self-resonance tuning piezoelectric energy harvester with broadband frequency, including: a piezoelectric beam which is extended along a horizontal direction; a fixing member which fixes opposite ends of the piezoelectric beam; and a mobile mass which the piezoelectric beam passes through, and which is capable of self-movement along the piezoelectric beam through a through-hole which has a free space in addition to a space which the piezoelectric beam passes through, wherein as the mobile mass moves to a position of the piezoelectric beam, generated displacement of a piezoelectric beam is increased, and as the generated displacement becomes greater than the free space, the mobile mass is fixed to a position of a piezoelectric beam at which resonance will occur.

Provided herein is a modulating retroreflective multilayer film comprising retroreflective elements, a piezoelectric layer, a photovoltaic layer, and an energy storage device. The stacked and transparent layered configuration of the film allows the retroreflective elements and the photovoltaic layer to be simultaneously illuminated by a narrow beam. The low power piezoelectric layer and the energy harvesting of the photovoltaic layer allow the retroreflector to be energetically self-sufficient and suitable for remote deployment. The flexible properties of the component layers allow the retroreflector to be adhered to nonplanar or irregular surfaces for the purpose of labeling and tagging.

A method for polarizing a piezoelectric film is described. In this method, a piezoelectric film is formed by using an injection deposition method. The piezoelectric film is flat adhered to a surface of a conductive substrate. A polarization process is performed on the piezoelectric film while the piezoelectric film is flat adhered to the surface of the conductive substrate.

The semiconductor device includes a semiconductor element substrate having an insulation property, and a wire for positioning the semiconductor element with respect to the semiconductor element substrate. The semiconductor element substrate includes a disposition region for disposing the semiconductor element. The wire is provided at least at a part of the periphery of the disposition region.