A piezoelectric sensor and a manufacturing method therefor, and a detection apparatus, which relate to the technical field of sensing. The piezoelectric sensor includes: an array substrate: a first capping layer located on the array substrate and including a first portion and a second portion, wherein the first portion covers the array substrate, a cavity is provided between the second portion and the array substrate, and the second portion is provided with a first opening: a first electrode located above the first capping layer and above the cavity, a piezoelectric thin film located on the first electrode, and a second electrode located on the piezoelectric thin film.

Various embodiments may provide an electromechanical responsive film. The electromechanical responsive film may include a composition including sodium (Na), potassium (K), niobium (Nb) and oxygen (O). The composition may have a formula (Na.sub.xK.sub.y)NbO.sub.3-δ, wherein 0≤x<1, wherein 0≤y<1, and wherein 0<x+y<1. The composition may satisfy at least one condition selected from a group consisting of a first condition of (x+y+4)/2≤(3−δ)≤(x+y+5)/2 and a second condition of 0<δ<1.

A piezoelectric thin film includes a first piezoelectric layer and a second piezoelectric layer directly stacked on the first piezoelectric layer. The first piezoelectric layer contains a tetragonal crystal 1 of a perovskite-type oxide. The second piezoelectric layer contains a tetragonal crystal 2 of a perovskite-type oxide. A (001) plane of the tetragonal crystal 1 is oriented in a normal direction do of a surface of the piezoelectric thin film. A (001) plane of the tetragonal crystal 2 is oriented in the normal direction dn of the surface of the piezoelectric thin film. An interval of the (001) plane of the tetragonal crystal 1 is c1, an interval of a (100) plane of the tetragonal crystal 1 is a1, an interval of the (001) plane of the tetragonal crystal 2 is c2, an interval of a (100) plane of the tetragonal crystal 2 is a2, c2/a2 is more than c1/a1 and c1/a1 is from 1.015 to 1.050.

The disclosure provides an electricity generating insert for a piece of footwear, the insert can be removably placed in the heel portion, e.g. under the insole. The insert comprises a multilayer piezoelectric stack that alternatively flexes under the compression-decompression that occurs during locomotion, which flexing causes friction in the stack to generate electricity capable of charging electronic devices and the like, e.g. via a port on the footwear.

Provided are a piezoelectric material, a piezoelectric member, a piezoelectric element and a pressure sensor that can be used in high-temperature environments. The piezoelectric material is composed of Sr-substituted akermanite represented by Ca.sub.(2-x)Sr.sub.xMgSi.sub.2O.sub.7 (0.1≤x≤0.6).

A piezoelectric element that includes a substrate, a lower electrode layer on the substrate, an intermediate layer on the lower electrode layer, and an upper electrode layer on the intermediate layer. The intermediate layer includes a first piezoelectric layer including an aluminum nitride as a main component thereof and located between the lower electrode layer and the upper electrode layer, a first buffer layer including an aluminum nitride as a main component and located between the first piezoelectric layer and the upper electrode layer, a first intermediate electrode layer located between the first buffer layer and the upper electrode layer, and a second piezoelectric layer located between the first intermediate electrode layer and the upper electrode layer.

A piezoelectric transformer comprises at least a laminate of a first member, a first piezoelectric element, a second piezoelectric element and a second member sequentially stacked one on the other in the above-listed order and a pressurizing mechanism for squeezing the first member and the second member together in the stacking direction. The ratio of the electromechanical coupling coefficient k.sub.33 relative to the electromechanical coupling coefficient k.sub.31 (k.sub.33/k.sub.31) of the first piezoelectric element and the second piezoelectric element is not less than 2.0.

Provided is a lead-free piezoelectric material reduced in dielectric loss tangent, and achieving both a large piezoelectric constant and a large mechanical quality factor. A piezoelectric material according to at least one embodiment of the present disclosure is a piezoelectric material including a main component formed of a perovskite-type metal oxide represented by the general formula (1): Na.sub.x+s(1−y)(Bi.sub.wBa.sub.1−s−w).sub.1−yNb.sub.yTi.sub.1−yO.sub.3 (where 0.84≤x≤0.92, 0.84≤y≤0.92, 0.002≤(w+s)(1−y)≤0.035, and 0.9≤w/s≤1.1), and a Mn component, wherein the content of the Mn is 0.01 mol % or more and 1.00 mol % or less with respect to the perovskite-type metal oxide.

A relaxor-PT based piezoelectric crystal is disclosed, comprising the general formula of (Pb.sub.1-1.5xM.sub.x){[(M.sub.I,M.sub.II).sub.1-z(M.sub.I′,M.sub.II′).sub.z].sub.1-yTi.sub.y}O.sub.3, wherein: M is a rare earth cation; M.sub.I is selected from the group consisting of Mg.sup.2+, Zn.sup.2+, Yb.sup.3+, Sc.sup.3+, and In.sup.3+; M.sub.II is Nb.sup.5+; M.sub.I′ is selected from the group consisting of Mg.sup.2+, Zn.sup.2+, Yb.sup.3+, Sc.sup.3+, In.sup.3+, and Zr.sup.4; M.sub.II′ is Nb.sup.5+ or Zr.sup.4+; 0<x≤0.05; 0.02<y<0.7; and 0≤z≤1, provided that if either M.sub.I′ or M.sub.II′ is Zr.sup.4+, both M.sub.I′ and M.sub.II′ are Zr.sup.4+. A method for forming the relaxor-PT based piezoelectric crystal is disclosed, comprising pre-synthesizing precursor materials by calcining mixed oxides, mixing the precursor materials with single oxides and calcining to form a feeding material, and growing the relaxor-PT based piezoelectric crystal having the general formula of (Pb.sub.1-1.5xM.sub.x){[(M.sub.I,M.sub.II).sub.1-z(M.sub.I′,M.sub.II′).sub.z].sub.1-yTi.sub.y}O.sub.3 from the feeding material by a Bridgman method.

A method of fabricating a piezoelectric layer includes depositing a piezoelectric material onto a substrate in a first crystallographic phase by physical vapor deposition while the substrate remains at a temperature below 400° C., and thermally annealing the substrate at a temperature above 500° C. to convert the piezoelectric material to a second crystallographic phase. The physical vapor deposition includes sputtering from a target in a plasma deposition chamber.