Abstract: An electretized film of the present invention includes a cyclic olefin polymer, in which the electretized film is a non-porous film, and a piezoelectric constant d33 in a thickness direction, which is measured by applying a pressing force to the electretized film in the thickness direction, under conditions of a load of 0.5 N, a dynamic load of ±0.25 N, a frequency of 110 Hz, a temperature of 23° C., and a humidity of 50%, is equal to or more than 100 pC/N.

Abstract: Provided is a piezoelectric structure including a braid composed of a conductive fiber and piezoelectric fibers, the braid being a covered fiber having the conductive fiber as the core and the piezoelectric fibers covering the periphery of the conductive fiber, wherein the covered fiber has at least one bent section, and when the piezoelectric structure is placed on a horizontal surface, the height from the horizontal surface to the uppermost section of the piezoelectric structure is greater than the diameter of the covered fiber.

Abstract: A structure includes an oriented piezoelectric polymer arranged in a circular tubular or circular columnar shape, wherein the orientation angle of the piezoelectric polymer with respect to the central axis of the structure is 15° to 75°, the piezoelectric polymer includes a crystalline polymer having an absolute value of 0.1 to 1000 pC/N for the piezoelectric constant d14 when the orientation axis is the third axis, and the piezoelectric polymer includes a P-body containing a crystalline polymer with a positive piezoelectric constant d14 value and an N-body containing a crystalline polymer with a negative value, wherein for the portion of the central axis of the structure having a length of 1 cm, the value of T1/T2 is 0 to 0.8, T1 being the smaller and T2 being the larger of (ZP+SN) and (SP+ZN), where ZP, SP, ZN, and SN are particularly defined masses.

Abstract: Provided is a piezoelectric laminate element that outputs a fixed output voltage even in response to a static load for which an output voltage could not be obtained using a conventional piezoelectric element. A piezoelectric laminate body in which a plurality of piezoelectric polymer film layers consisting of film such as polylactic acid film that exhibits piezoelectricity in the planar direction are laminated is used as a piezoelectric laminate element. The piezoelectric laminate body is given a cylindrical shape, rounded rectangle shape, or other partially curved shape. The output voltage follows the increase and decrease of the applied load, and if a fixed load is continuously applied, a fixed output voltage is continuously output, and a piezoelectric laminate element is obtained that outputs a fixed output voltage even if a load is static.

Abstract: Provided is a configuration capable of improving the signal strength of a piezoelectric element using piezoelectric fibers. This braided piezoelectric element comprises a core comprising conductive fibers and a sheath comprising braided piezoelectric fibers so as to cover the core, the braided piezoelectric element further comprising a metal terminal connected and fixed to the core in either of the following states A or B. A) A state where a portion of the metal terminal grasps a fiber portion constituting the end of a braided piezoelectric element and the core and the metal terminal are electrically connected to each other and fixed within 1 mm from where the metal terminal grasps the fiber portion.

Abstract: A polymer for organic ferroelectric materials and an organic ferroelectric materials are disclosed. The polymer is a (meth)acrylic polymer, wherein the polymer comprises one or more (meth)acrylates as main monomer units and one or more (meth)acrylic monomers other than the main monomer units, wherein the main monomer units are (meth)acrylate monomer units having in the side chain thereof a saturated or unsaturated hydrocarbon skeleton linked to the distal end of the oxycarbonyl group, wherein the hydrocarbon skeleton has a hydrogen atom on the ?-carbon atom relative to the oxycarbonyl group, and one or more electron withdrawing groups selected from halogen atom, cyano group, oxo group, and nitro group, that bind to the ?-carbon atom and/or to one or more carbon atoms distal thereto, substituting for hydrogen atoms thereon, wherein the proportion of the main monomer units is less than 80 mol % of the total (meth)acrylic monomer units.

Abstract: Provided is a piezoelectric structure comprising a braid composed of a conductive fiber and piezoelectric fibers, the braid being a covered fiber having the conductive fiber as the core and the piezoelectric fibers covering the periphery of the conductive fiber, wherein the covered fiber has at least one bent section, and when the piezoelectric structure is placed on a horizontal surface, the height from the horizontal surface to the uppermost section of the piezoelectric structure is greater than the diameter of the covered fiber.

Abstract: A piezoelectric stack includes a porous resin sheet, and a surface coating layer disposed on an exterior surface of the porous resin sheet, the exterior surface including at least one of a front surface and a back surface of the porous resin sheet, the surface coating layer having a volume resistivity of not less than 1×1013 ?·cm, the porous resin sheet and the surface coating layer having different elastic moduli.

Abstract: The purpose of the present invention is to provide a fibrous piezoelectric element which enables a large electric signal to be drawn out by stress produced by relatively small deformation. A piezoelectric element includes a braid composed of a conductive fiber and a piezoelectric fiber. In the braid, the conductive fiber is a core, and the piezoelectric fiber is a covering fiber that covers the periphery of the conductive fiber.

Abstract: The photoelastic polyurethane resin has a Young's modulus at 25° C. of 2 to 5 MPa, a photoelastic constant at 25° C. of 1000×10?12 Pa?1 to 100000×10?12 Pa?1, and a glass transition temperature of ?60° C. to ?21° C.

Abstract: An electretized film of the present invention includes a cyclic olefin polymer, in which the electretized film is a non-porous film, and a piezoelectric constant d33 in a thickness direction, which is measured by applying a pressing force to the electretized film in the thickness direction, under conditions of a load of 0.5 N, a dynamic load of ±0.25 N, a frequency of 110 Hz, a temperature of 23° C., and a humidity of 50%, is equal to or more than 100 pC/N.

Abstract: Provided is a piezoelectric laminate element that outputs a fixed output voltage even in response to a static load for which an output voltage could not be obtained using a conventional piezoelectric element. A piezoelectric laminate body in which a plurality of piezoelectric polymer film layers consisting of film such as polylactic acid film that exhibits piezoelectricity in the planar direction are laminated is used as a piezoelectric laminate element. The piezoelectric laminate body is given a cylindrical shape, rounded rectangle shape, or other partially curved shape. The output voltage follows the increase and decrease of the applied load, and if a fixed load is continuously applied, a fixed output voltage is continuously output, and a piezoelectric laminate element is obtained that outputs a fixed output voltage even if a load is static.

Abstract: The cushioning material having a sensor 1 includes a resin sheet 4 composed of photoelastic resin, a cushioning material 21 laminated on the resin sheet 4, a photosensor 15 including a light generating unit 5 and a light receiving unit 8 that are disposed to face each other so as to sandwich the resin sheet 4, and a processor 3 that detects a stress applied to the resin sheet 4 based on the light signal detected by the photosensor 15.

Abstract: A structure includes an oriented piezoelectric polymer arranged in a circular tubular or circular columnar shape, wherein the orientation angle of the piezoelectric polymer with respect to the central axis of the structure is 150 to 750, the piezoelectric polymer includes a crystalline polymer having an absolute value of 0.1 to 1000 pC/N for the piezoelectric constant d14 when the orientation axis is the third axis, and the piezoelectric polymer includes a P-body containing a crystalline polymer with a positive piezoelectric constant d14 value and an N-body containing a crystalline polymer with a negative value, wherein for the portion of the central axis of the structure having a length of 1 cm, the value of T1/T2 is 0 to 0.8, T1 being the smaller and T2 being the larger of (ZP+SN) and (SP+ZN), where ZP, SP, ZN, and SN are particularly defined masses.

Abstract: Provided is a configuration capable of improving the signal strength of a piezoelectric element using piezoelectric fibers. This braided piezoelectric element comprises a core comprising conductive fibers and a sheath comprising braided piezoelectric fibers so as to cover the core, the braided piezoelectric element further comprising a metal terminal connected and fixed to the core in either of the following states A or B. A) A state where a portion of the metal terminal grasps a fiber portion constituting the end of a braided piezoelectric element and the core and the metal terminal are electrically connected to each other and fixed within 1 mm from where the metal terminal grasps the fiber portion.

Abstract: A piezoelectric device is provided that includes a polymer piezoelectric material having at least one film-like layer; a first electric conductor provided on a principal surface of the polymer piezoelectric material; a second electric conductor provided on a surface of the polymer piezoelectric material at an opposite side from the first electric conductor on the principal surface; a first end surface electric conductor provided on one end surface in a width direction of the polymer piezoelectric material and disposed so as to be conductively connected to the first electric conductor and so as not to be in contact with the second electric conductor; and a second end surface electric conductor provided on any other end surface that is not the one end surface of the polymer piezoelectric material and disposed in a defined manner.

Abstract: The purpose of the present invention is to provide a fibrous piezoelectric element which enables a large electric signal to be drawn out by stress produced by relatively small deformation. A piezoelectric element includes a braid composed of a conductive fiber and a piezoelectric fiber. In the braid, the conductive fiber is a core, and the piezoelectric fiber is a covering fiber that covers the periphery of the conductive fiber.

Abstract: The object of the present invention is to provide a laminated film made of polylactic acids which is not prone to delamination while having excellent piezoelectric properties and a manufacturing method thereof. That is, the present invention is obtained by the stretched laminated film manufactured by a co-extrusion process for use in piezoelectric polymer materials, containing a layer (A) which has poly-L-lactic acid as the primary component and contains an impact modifier in the range of 0.1 to 10 mass % and a layer (B) which has poly-D-lactic acid as the primary component and contains an impact modifier in the range of 0.1 to 10 mass %.

Abstract: The invention relates to a piezoelectric vibrator having a piezoelectric laminate in which oriented film layers made of a polylactic acid and conductive layers are laminated alternately and grippers gripping both ends of the piezoelectric laminate, wherein one of two conductive layers neighboring via an oriented film layer is short-circuited to a negative electrode and the other conductive layer is short-circuited to a positive electrode, the oriented film layers interposed between the respective conductive layers are laminated such that the oriented film layers expand and contract in the same direction when a current is applied, the piezoelectric laminate has two parallel surfaces which are parallel to the plane direction of the oriented film layers and two end faces A and B which are between the parallel surfaces and parallel to each other, and the gripped ends respectively include the end face A and the end face B.

Abstract: The photoelastic polyurethane resin has a Young's modulus at 25° C. of 2 to 5 MPa, a photoelastic constant at 25° C. of 1000×10?12 Pa?1 to 100000×10?12 Pa?1, and a glass transition temperature of ?60° C. to ?21° C.