A vibrator includes an electromechanical transducer which is a piezoelectric ceramic made of sodium-potassium niobate metal oxides and whose temperature characteristics of a relative permittivity is 500 [ppm/° C.] or less in absolute value in a temperature range from −40° C. to 170° C., wherein excitation of the electromechanical transducer produces a vibration wave. Another vibrator includes an electromechanical transducer which is a piezoelectric ceramic made of sodium-potassium niobate metal oxides and whose temperature characteristics of a relative permittivity is 390 [ppm/° C.] or less in absolute value in a temperature range from 0° C. to 60° C., wherein excitation of the electromechanical transducer produces a vibration wave.

A bonded body includes a supporting substrate, silicon oxide layer provided on the supporting substrate, and a piezoelectric material substrate provided on the silicon oxide layer and composed of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalite. A nitrogen concentration at an interface between the piezoelectric material substrate and silicon oxide layer is higher than a nitrogen concentration at an interface between the silicon oxide layer and the supporting substrate.

A bonded body includes a supporting substrate, silicon oxide layer provided on the supporting substrate, and a piezoelectric material substrate provided on the silicon oxide layer and composed of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalite. A nitrogen concentration at an interface between the piezoelectric material substrate and silicon oxide layer is higher than a nitrogen concentration at an interface between the silicon oxide layer and the supporting substrate.

A composite substrate includes a final substrate, and a piezoelectric material directly molecularly bonded to the final substrate at a first interface. The piezoelectric material comprises an epitaxial layer, but does not comprise a seed layer. Additional composite substrates include a final substrate, and a piezoelectric material directly molecularly bonded to the final substrate at a first interface. The piezoelectric material comprises an epitaxial layer. The composite substrate further includes a seed layer on which the piezoelectric material has been epitaxially grown. The seed layer is disposed on a side of the epitaxial layer opposite the final substrate. An acoustic wave device comprises such a composite substrate with at least one electrode on a surface of the piezoelectric layer opposite the substrate.

A composite substrate includes a final substrate, and a piezoelectric material directly molecularly bonded to the final substrate at a first interface. The piezoelectric material comprises an epitaxial layer, but does not comprise a seed layer. Additional composite substrates include a final substrate, and a piezoelectric material directly molecularly bonded to the final substrate at a first interface. The piezoelectric material comprises an epitaxial layer. The composite substrate further includes a seed layer on which the piezoelectric material has been epitaxially grown. The seed layer is disposed on a side of the epitaxial layer opposite the final substrate. An acoustic wave device comprises such a composite substrate with at least one electrode on a surface of the piezoelectric layer opposite the substrate.

Provided is an actuator including a piezoelectric element capable of satisfying three of a large amplitude, a high resonance frequency, and a large generated force. Actuator (100) is a drive source having a cantilever structure in which one end is a fixed end and the other end is displaced, and includes first piezoelectric body (110), second piezoelectric body (120), and shim member base (130) disposed between first piezoelectric body (110) and second piezoelectric body (120). In first piezoelectric body (110) and second piezoelectric body (120), piezoelectric body removal parts (110a) and (120a) are formed.

Provided is an actuator including a piezoelectric element capable of satisfying three of a large amplitude, a high resonance frequency, and a large generated force. Actuator (100) is a drive source having a cantilever structure in which one end is a fixed end and the other end is displaced, and includes first piezoelectric body (110), second piezoelectric body (120), and shim member base (130) disposed between first piezoelectric body (110) and second piezoelectric body (120). In first piezoelectric body (110) and second piezoelectric body (120), piezoelectric body removal parts (110a) and (120a) are formed.

A vibration apparatus can include a first cover member; a second cover member; a vibration portion between the first cover member and the second cover member; a contact portion between the first cover member and the vibration portion; and a signal cable. The signal cable can include a first signal line connected to a first surface of the vibration portion via the contact portion, and a second signal line connected to a second surface of the vibration portion opposite to the first surface of the vibration portion.

The vibration apparatus may include a vibration generating portion including a first vibration portion and a second vibration portion overlapping the first vibration portion, a first cover member at a first surface of the vibration generating portion, a second cover member at a second surface different from the first surface of the vibration generating portion, and a signal cable including first, second and third signal lines connected to the first vibration portion and the second vibration portion and disposed between the first cover member and the second cover member. An apparatus for vibration may include a passive vibration member and the vibration apparatus.

The vibration apparatus may include a vibration generating portion including a first vibration portion and a second vibration portion overlapping the first vibration portion, a first cover member at a first surface of the vibration generating portion, a second cover member at a second surface different from the first surface of the vibration generating portion, and a signal cable including first, second and third signal lines connected to the first vibration portion and the second vibration portion and disposed between the first cover member and the second cover member. An apparatus for vibration may include a passive vibration member and the vibration apparatus.