A polymeric piezoelectric material, comprising at least two regions: a region H, which is an oriented polymeric piezoelectric region that includes an optically active helical chiral polymer (A) having a weight average molecular weight of from 50,000 to 1,000,000, the region H having a crystallinity of from 20% to 80% and having a standardized molecular orientation-of from 3.5 to 15.0; and a region L, which is a low orientation region that includes the optically active helical chiral polymer (A) having a weight average molecular weight of from 50,000 to 1,000,000, the region L being present near at least part of an end portion of the region H, having an average width when viewed from a normal direction with respect to the principal plane of the region H of from 10 μm to 300 μm, and having a retardation is 100 nm or less.

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.

Disclosed herein is a buckling actuator, comprising: a first electrode; a second electrode; and a film of a dielectric elastomeric material having a first surface and a second surface sandwiched between the first and second electrodes, wherein the material is formed by the random block copolymerisation of a polymeric material comprising silicon or nitrogen atoms that has two or more acrylate or vinyl end groups, and a polar polymeric material having two or more acrylate or vinyl end groups. Also disclosed herein is a method of forming said dielectric elastomeric material.

Provided is a polymeric piezoelectric film containing an optically active helical chiral polymer (A) having a weight average molecular weight of from 50,000 to 1,000,000, in which a crystallinity obtained by a DSC method is from 20% to 80%, and the product of the crystallinity and a standardized molecular orientation MORc when a reference thickness measured by a microwave transmission-type molecular orientation meter is set to 50 μm is from 25 to 700, and in which a surface roughness of at least one plane in terms of a non-contact three-dimensional surface roughness Sa measured by a confocal laser microscope is from 0.040 μm to 0.105 μm.

An object of the present invention is to provide a laminated piezoelectric element in which piezoelectric films are laminated, capable of easily performing connection of an electrode layer of each piezoelectric film and an external device. The piezoelectric film includes a piezoelectric layer and a laminated sheet in which an electrode layer and a protective layer are laminated, piezoelectric layers are arranged between the laminated sheets facing the electrode layer, the laminated sheet includes a protruding portion protruding from the piezoelectric layer, the protruding portion is provided with a lead-out wire attached to a surface between the electrode layer and the protective layer, and the object is achieved by contacting the lead-out wire and connecting electrode layers having a same polarity of each piezoelectric film.

In a method of manufacturing an object, a filament is fed to an extrusion head. The filament has a semi-crystalline polymeric reinforcement portion and a polymeric matrix portion. The temperature of the filament is raised in the extrusion head above the melting point of the matrix portion but below the melting point of the reinforcement portion so that the matrix portion of the filament melts within the extrusion head, thereby forming a partially molten filament within the extrusion head. The reinforcement portion of the partially molten filament remains in a semi-crystalline state as it is extruded from the extrusion head. Relative movement is generated between the extrusion head and the substrate as the partially molten filament is extruded onto the substrate in order to form an extruded line on the substrate. The matrix portion of the extruded line solidifies after the extruded line has been formed on the substrate.

The invention relates to methods and compositions for preparing silk-based piezoelectric materials and methods for increasing piezoelectricity in silk matrices.

An apparatus comprising a frame and a pressure sensitive adhesive applied to at least a portion of the frame, where the pressure sensitive adhesive is arranged to bond a pre-strained film to the frame is disclosed. A method of making the apparatus also is disclosed. Also disclosed is a method of preparing a stretch frame for manufacturing electroactive polymer devices thereon.

A flexoelectricity ultrasonic (UT) transducer imaging system is disclosed comprising a polytetrafluoroethylene (PTFE) layer, a plurality of flexoelectricity UT transducers, and a multiplexer. The PTFE layer includes a front and back surface and the plurality of flexoelectricity UT transducers is attached to the back surface of the PTFE layer. Each UT transducer has a front-end and back-end and the front-end of each flexoelectricity UT transducer is attached to the back surface of the PTFE layer. The flexoelectricity UT transducers are arranged along the back surface of the PTFE layer as a two-dimensional array and each flexoelectricity UT transducer is configured to vibrate in a normal direction to the back surface of the PTFE layer. The multiplexer in signal communication with each flexoelectricity UT transducer, where the flexoelectricity UT transducers are sandwiched between the multiplexer and the PTFE layer.

A method for manufacturing an electroactive polymer device which includes a layered structure including a dielectric polymer layer and an electrode layer, wherein the electrode layer is arranged on a surface of the dielectric polymer layer. The method includes: providing the dielectric polymer layer; determining a surface area location of a defect on a first surface of the dielectric polymer layer; creating an electrode layer including an area void of electrode layer material surrounding the surface area location, and the electrode layer includes a patch of electrode material covering the surface area location and a remainder part of the surface of the dielectric polymer layer surrounding the area void of electrode layer material, in which the patch and the remainder part are electrically isolated from one another.