An external rear view device for a motor vehicle includes a casing which has at least one part made from a polymer, wherein the at least one part of the casing comprises piezo-electrical particles and at least one conductive element which is in electrical contact with the piezo-electrical particles and inductively coupled to a power storage unit. A motor vehicle with such a rear view device is also described.

A wire-free multilayer biomorph device is provided where the layers are bonded without use of adhesive. The device includes a plurality of stacked perforated metal plates with interposed transductive assembly layers. The perforated metal plates and transductive assembly layers are bonded by a conductive metal ink that is subject to a thermal cycle process. Electrical connection of the perforated metal plates and transductive assembly are realized through structural connectors thru-connectors thereby obviating the need for wiring.

Provided is a piezoelectric thin film containing a tetragonal crystal 1 of a perovskite type oxide and a tetragonal crystal 2 of the oxide. A (001) plane of the tetragonal crystal 1 and a (001) plane of the tetragonal crystal 2 are oriented in a normal direction of a surface of the piezoelectric thin film. An interval of the (001) plane of the crystal 1 is c1. An interval of a (100) plane of the crystal 1 is al. An interval of the (001) plane of the crystal 2 is c2. An interval of a (100) plane of the crystal 2 is a2. c2/a2 is more than c1/a1. A peak intensity of diffracted X-rays of the (001) plane of the crystal 1 is I.sub.1. A peak intensity of diffracted X-rays of the (001) plane of the crystal 2 is I.sub.2. I.sub.2(I.sub.1+I.sub.2) is from 0.50 to 0.90.

The invention relates to a method for producing ceramics having piezoelectric properties in predominantly aqueous suspending agents.

The present invention relates to a ceramic comprising (or consisting essentially of) a solid solution containing Bi, K, Ti and Fe (and optionally Pb) which exhibits piezoelectric behaviour.

A piezoelectric element includes a substrate, a first electrode formed on the substrate, a piezoelectric layer, which is a layered structure of a plurality of piezoelectric films each containing potassium, sodium, and niobium, formed on the first electrode, and a second electrode formed on the piezoelectric layer. A sodium concentration in the piezoelectric layer has a Na local maximum value, which is a local maximum value of the sodium concentration, in a first piezoelectric film, which is among the plurality of piezoelectric films, in the vicinity of the first electrode, a sodium concentration gradient decreasing from the Na local maximum value toward the second electrode, and a Na local minimum value, which is a local minimum value of the sodium concentration, near a boundary between the first piezoelectric film and a second piezoelectric film formed immediately above the first piezoelectric film.

This piezoelectric element includes a lower electrode formed on a substrate, a piezoelectric layer formed on the lower electrode, and an upper electrode formed on the piezoelectric layer. The upper electrode includes a first upper electrode layer made of a metal oxide including an amorphous portion at least at a boundary with the piezoelectric layer and a second upper electrode layer formed on the first upper electrode layer.

A piezoelectric composition comprises a plurality of crystal particles, wherein the piezoelectric composition includes bismuth, iron, barium, titanium, and oxygen; the crystal particle include a core and a shell having a contents of bismuth higher than that in the core and covering the core; and the total area of the cross sections of the cores exposed to the cross section of the piezoelectric composition is expressed as S.sub.CORE, the total area of the cross sections of the shells exposed to the cross section of the piezoelectric composition is expressed as S.sub.SHELL, and 100.Math.S.sub.CORE/(S.sub.CORE+S.sub.SHELL) is 50 to 90.

A piezoelectric composition comprises a plurality of crystal particles, wherein the piezoelectric composition includes bismuth, iron, barium, titanium, and oxygen; the crystal particles include a core and a shell covering the core; the average value of the contents of bismuth in the cores is expressed as C.sub.CORE % by mass, the average value of the contents of bismuth in the shells is expressed as C.sub.SHELL % by mass, and the C.sub.CORE is lower than the C.sub.SHELL; and the number of all the particles comprised in the piezoelectric composition is expressed as N, the number of the crystal particles including the core and the shell is expressed as n, and n/N is 0.10 to 1.00.

The piezoelectric composition is represented by the following Chemical Formula (1):

x[Bi.sub.mFeO.sub.3]-y[Ba.sub.mTiO.sub.3]-z[Sr.sub.mTiO.sub.3](1)

wherein 0.5x0.8, 0.02y0.4, 0.02z0.2, x+y+z=1, and 0.96m1.04.