Among other things, piezoelectric materials and methods of their manufacture are described; particularly methods of forming regions of varying crystal structure within a relaxor piezoelectric substrate. Such methods may including heating the piezoelectric substrate above the transition temperature and below the Curie temperature such that a first phase transition occurs to a first crystal structure; rapidly cooling the piezoelectric substrate below the transition temperature at a cooling rate that is sufficiently high for the first crystal structure to persist; and applying an electric field through one or more selected regions of the piezoelectric substrate, such that within the one or more selected regions, a second phase transition occurs and results in a second crystal structure.

A piezoelectric monocrystalline substrate is composed of a material represented by LiAO.sub.3 (A represents at least one element selected from the group consisting of niobium and tantalum), a bonding layer is compose of a material of an oxide of at least one element selected from the group consisting of niobium and tantalum, and an interface layer is provided along an interface between the piezoelectric monocrystalline substrate 6 and bonding layer, and the interface layer has a composition of E.sub.xO.sub.(1-x) (E represents at least one element selected from the group consisting of niobium and tantalum and 0.29≤x≤0.89).

Provided is a piezoelectric material filler including alkali niobate compound particles having a ratio (K/(Na+K)) of the number of moles of potassium to the total number of moles of sodium and potassium of 0.460 to 0.495 in terms of atoms and a ratio ((Li+Na+K)/Nb) of the total number of moles of alkali metal elements to the number of moles of niobium of 0.995 to 1.005 in terms of atoms. The present invention can provide a piezoelectric material filler having excellent piezoelectric properties, and a composite piezoelectric material including the piezoelectric material filler and a polymer matrix.

There is provided a piezoelectric material not containing any lead component, having stable piezoelectric characteristics in an operating temperature range, a high mechanical quality factor, and satisfactory piezoelectric characteristics. The piezoelectric material includes a main component containing a perovskite-type metal oxide that can be expressed using the following general formula (1), and subcomponents containing Mn, Li, and Bi. When the metal oxide is 100 parts by weight, the content of Mn on a metal basis is not less than 0.04 parts by weight and is not greater than 0.36 parts by weight, content α of Li on a metal basis is not less than 0.0013 parts by weight and is not greater than 0.0280 parts by weight, and content β of Bi on a metal basis is not less than 0.042 parts by weight and is not greater than 0.850 parts by weight
(Ba.sub.1-xCa.sub.x).sub.a(Ti.sub.1-y-zZr.sub.ySn.sub.z)O.sub.3  (1)
(in the formula (1), 0.09≦x≦0.30, 0.074<y≦0.085, 0≦z≦0.02, and 0.986≦a≦1.02).

Chemical sensors include a functionalized electrode configured to change surface potential in the presence of an analyte. A piezoelectric element is connected to the functionalized electrode. A piezoresistive element is in contact with the piezoelectric element.

A piezoelectric material contains ferroelectric particles and an adhesive resin. The ratio of the ferroelectric particles relative to the total mass of the ferroelectric particles and the adhesive resin is 40 mass % or greater and 98 mass % or less.

An impact sensor for a vehicle. The impact sensor includes at least one strain-sensitive sensor element which comprises a sensor material, and at least two terminals, between which the sensor material is electrically connected. The sensor material is a metal-containing carbon material.

A piezoelectric capacitor includes A) a composite article that has 1) a dry piezoelectric layer (dry PL); 2) a first dry electrode comprising a dry electrically-conductive layer arranged contiguously with a first opposing surface of the dry PL; and 3) a second dry electrode arranged contiguously with a second opposing surface of the dry PL. The dry electrically-conductive layer has essentially (a) an electrically-conductive material; and (b) particles having a Young's modulus that is different from the Young's modulus of the (a) electrically-conductive material by at least 10%. The capacitor also has B) electrical communication means attached to both electrodes for electrical communication of the composite article with an external electrical circuit.

A piezoelectric/electrostrictive (“PE”) actuator includes a PE element including a laminated object having a PE layer and a pair of electrodes arranged respectively on both sides of the PE layer, and having an operating part corresponding to the portion in which the PE layer is sandwiched between the pair of electrodes and a non-operating part corresponding to the portion in which the PE layer is not sandwiched between the pair of electrodes, and a moisture-proof film covering at least the vicinity of a boundary between the operating part and the non-operating part, consisting of a liquid with a saturated moisture content at 25 degree Celsius of 300 ppm or less and a withstand voltage at the saturated moisture content of not less than 6 kV/mm. The liquid contains hydrocarbon system organic compound having a main backbone of carbon-carbon bond and consisting only of carbon and hydrogen.

The present invention is a piezoelectric composition and a piezoelectric element using the piezoelectric composition, the composition being characterized by: having a Perovskite structure represented by general formula ABO3; being represented by composition formula x(Bi0.5K0.5)TiO3-yBi(Mg0.5Ti0.5)O3-zBiFeO3, x+y+z=1 in the composition formula above; and in a triangular coordinate using x, y and z in the composition formula above, having a composition represented by a region which is surrounded by a pentagon ABCDE with apexes of point A (1, 0, 0), point B (0.7, 0.3, 0), point C (0.1, 0.3, 0.6), point D (0.1, 0.1, 0.8) and point E (0.2, 0, 0.8) and which does not include the line segment AE that connects point A (1, 0, 0) and point E (0.2, 0, 0.8).