Medical devices configured to direct sound waves to a body tissue of a subject are provided. The medical device includes a housing and a curved piezoelectric transducer, where the curved piezoelectric transducer is configured to direct sound waves produced by the curved piezoelectric transducer to the body tissue of the subject. Also provided are methods of directing sound waves to a body tissue of a subject using the subject medical devices. The subject medical devices and methods find use in a variety of applications where the treatment of a body tissue of a subject with sound waves is desired.

A piezoelectric thin film contains a metal oxide having a perovskite structure. The metal oxide contains bismuth, potassium, titanium, magnesium, iron, and an element M. The element M is at least one element selected from the group consisting of gallium and cobalt. At least a part of the metal oxide is at least one crystal selected from the group consisting of a tetragonal crystal and an orthorhombic crystal. A (001) plane of the crystal is oriented in a normal direction of a surface of the piezoelectric thin film.

In a method of manufacturing a piezoelectric device, during an isolation formation step, a supporting substrate has a piezoelectric thin film formed on its front with a compressive stress film present on its back. The compressive stress film compresses the surface on a piezoelectric single crystal substrate side of the supporting substrate, and the piezoelectric thin film compresses the back of the supporting substrate, which is opposite to the surface on the piezoelectric single crystal substrate side. Thus, the compressive stress produced by the compressive stress film and that produced by the piezoelectric thin film are balanced in the supporting substrate, which causes the supporting substrate to be free of warpage and remain flat. A driving force that induces isolation in the isolation formation step is gasification of the implanted ionized element rather than the compressive stress to the isolation plane produced by the piezoelectric thin film.

A piezoelectric device includes a supporting body, a supporting layer that is stacked on the supporting body, a first electrode that is formed on a side opposite to the supporting body side of the supporting layer, a piezoelectric body that is formed on a side opposite to the supporting layer side of the first electrode, and a second electrode that is formed on a side opposite to the first electrode side of the piezoelectric body, in which the piezoelectric body is formed throughout an area covering the first electrode, the second electrode is formed throughout an area covering the piezoelectric body, and a recess portion which is recessed toward the supporting body is formed outside an area overlapping with the first electrode in the supporting layer.

According to an embodiment, a microelectromechanical systems MEMS transducer includes a deflectable membrane attached to a support structure, an acoustic valve structure configured to cause the deflectable membrane to be acoustically transparent in a first mode and acoustically visible in a second mode, and an actuating mechanism coupled to the deflectable membrane. Other embodiments include corresponding systems and apparatus, each configured to perform various embodiment methods.

A vibrating plate is provided between a substrate and a piezoelectric element formed of electrodes and a piezoelectric layer and includes a first layer which is formed of a silicon oxide and a second layer which is formed of a ceramic having a Young's modulus larger than that of the silicon oxide. Under the condition in which the following expression (1) has a constant value, where in the expression (1), E.sub.v1, d.sub.v1, E.sub.v2, and d.sub.v2 represent Young's modulus of the first layer, the thickness thereof, Young's modulus of the second layer, and the thickness thereof,

E.sub.v1d.sub.v1.sup.2+E.sub.v2d.sub.v2.sup.2(1)

when the combination of d.sub.v1 and d.sub.v2 which sets the value of the following expression (2) in a range of from the minimum value to +2% thereof is represented by (D.sub.v1, D.sub.v2),

E.sub.v1d.sub.v1.sup.3+E.sub.v2d.sub.v2.sup.3(2)

the thickness of the first layer and the thickness of the second layer are represented by D.sub.v1 and D.sub.v2.

To enhance properties of a ferromagnetic film formed on a substrate. One aspect of the present invention is a film structure body having a single crystal substrate, and a first ferromagnetic film oriented and formed on the single crystal substrate.

A method for controlling a piezoelectric device including a piezoelectric element attached to a substrate, with the substrate and the piezoelectric element being made of materials having different coefficients of thermal expansion includes the step of subjecting the piezoelectric element to a predetermined electric voltage in order to cause a predetermined set deformation of the piezoelectric element. The predetermined electric voltage comprises a compensation portion determined according to ambient temperature to cancel a stress generated on the piezoelectric element due to a differential thermal expansion between the piezoelectric element and the substrate.

Curved piezoelectric transducers are provided. The curved piezoelectric transducer includes a substrate, a curved support layer having a peripheral portion in contact with the substrate, and a curved piezoelectric element disposed on the curved support layer. Methods of making the curved piezoelectric transducers are also provided. The curved piezoelectric transducers, devices and methods find use in a variety of applications, including devices, such as electronics devices, having one or more (e.g., an array) of the curved piezoelectric transducers on a substrate.

A composite substrate according to the present invention includes a support substrate having a diameter of 2 inches or more, and a piezoelectric substrate having a thickness of 20 m or less and bonded to the support substrate to transmit light. The piezoelectric substrate has a thickness distribution shaped like a fringe. A waveform having an amplitude within a range of 5 to 100 nm in a thickness direction and a pitch within a range of 0.5 to 20 mm in a width direction appears in the thickness distribution of the piezoelectric substrate in a cross section of the composite substrate taken along a line orthogonal to the fringe, and the pitch of the waveform correlates with a width of the fringe. In the piezoelectric substrate, the fringe may include either parallel fringes or spiral or concentric fringes.