The invention relates to a method for preparing a sol-gel solution which can be used to prepare a barium titanate ceramic doped with hafnium and/or with at least one lanthanide element, comprising the following steps: a) a step to place a first mixture comprising a barium carboxylate and a diol solvent in contact with a second mixture comprising a titanium alkoxide and a hafnium alkoxide and/or an alkoxide of a lanthanide element in a monoalcohol solvent; b) a step to distil the mixture resulting from step a) to remove at least part of the monoalcohol solvent; c) a step to add acetic acid, under heat, to the distilled mixture of step b).

A piezoelectric PTZT film is formed of a metal oxide having a perovskite structure including Pb, Ta, Zr, and Ti, in which the metal oxide further includes carbon, and a content of the carbon is 80 to 800 ppm by mass. In a process for producing a liquid composition for forming a piezoelectric film, a Ta alkoxide, a Zr alkoxide, -diketones, and a diol are refluxed, a Ti alkoxide is added into a first synthesis solution obtained by the refluxing, and then refluxing is performed again, a Pb compound is added into a second synthesis solution obtained by performing the additional refluxing, and then refluxing is performed again, a solvent is removed from a third synthesis solution obtained by performing the additional refluxing, and then, dilution with alcohol is performed, to produce the liquid composition for forming a piezoelectric PTZT film.

An electromechanical transducer element includes a first electrode on a substrate, an electromechanical transducer film on the first electrode, and a second electrode on the electromechanical transducer film. The electromechanical transducer film includes a thin line pattern. The thin line pattern includes a plurality of thin lines that are spaced away from each other.

Provided is use of an oriented piezoelectric film including of a perovskite-type crystal represented by the following general formula (1): Ba.sub.1-xCa.sub.xTi.sub.1-yZr.sub.yO.sub.3 (0x0.2, 0y0.2) (1). The oriented piezoelectric film is formed on an oriented underlayer oriented in a (111) plane and contains first crystals oriented in the (111) plane with respect to a film surface and randomly oriented second crystal grains. The first crystal grains have an average grain diameter of from 300 nm to 600 nm and the second crystal grains have an average grain diameter of from 50 nm to 200 nm.

An oriented piezoelectric film, wherein a crystal forming the oriented piezoelectric film, is a perovskite type crystal of the general formula of Ba.sub.1-xCa.sub.xTi.sub.1-yZr.sub.yO.sub.3 (0x0.2, and 0y0.2), and the oriented piezoelectric film has (111) orientation according to a pseudocubic crystal notation.

A biodegradable and biocompatible piezoelectric nanofiber platform for medical implant applications, including a highly sensitive, wireless, biodegradable force sensor for the monitoring of physiological pressures, and a biodegradable ultrasonic transducer for the delivery of therapeutics or pharmaceuticals across the blood-brain barrier.

A piezoelectric film having a porosity between 20 and 40%, a thickness ranging from tens of microns to less than a few millimeters can be used to form an ultrasonic transducer UT for operation in elevated temperature ranges, that emit pulses having a high bandwidth. Such piezoelectric films exhibit greater flexibility allowing for conformation of the UT to a surface, and obviate the need for couplings or backings. Furthermore, a method of fabricating an UT having these advantages as well as better bonding between the piezoelectric film and electrodes involves controlling porosity within the piezoelectric film.

A piezoelectric element includes a first electrode, a second electrode, and a piezoelectric layer. The piezoelectric layer is provided between the first electrode and the second electrode, and is formed of a perovskite type oxide which contains potassium, sodium, niobium, and manganese. In the piezoelectric layer, a proportion of an A-site constituent element of the perovskite type oxide is smaller than a proportion of a B-site constituent element thereof. In XRD measurement of the piezoelectric layer, two or more peaks derived from the perovskite type oxide are provided in a range of 44<2<48, and an intensity ratio (X/Y) between a peak X having the highest intensity among the peaks, and a peak Y having the lowest intensity satisfies the following expression.
2.0<(X/Y)

A piezoelectric element includes a substrate; a first electrode formed above the substrate; a piezoelectric layer which contains a composite oxide having a perovskite crystal structure and which is formed above the first electrode; and a second electrode formed above the piezoelectric layer, and the amount of carbon contained in the substrate is 0.26 to less than 14.00 percent by atom.

The present invention relates to a piezoelectric nanogenerator (PENG) that is capable of harvesting mechanical energy into electricity. The PENG comprises one dimensional (1D) and two dimensional (2D) nanostructures integrated together to form a composite nanostructure. A major advantage of the present invention is that the composite nanostructure provides enhanced electrical output and enhanced mechanical stability as compared to previously reported 1D or 2D nanostructures alone. Also described is a hybrid nanogenerator that combines the PENG with a triboelectric nanogenerator (TENG). A method of synthesizing the composite nanostructure PENG, in which the 1D and 2D nanostructures are grown together on the same substrate using a low temperature hydrothermal method is also described. The provided method is simple and cost-effective.