In one embodiment, a transducer comprises a first piezoelectric stack comprising a piezoelectric material; a first layer in contact with the piezoelectric stack; and a base structure beneath the first layer. The first layer has a first displacement between a first portion of the base structure and the first layer, and the first displacement is configurable by a first bias voltage received by the transducer.

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.

A piezoelectric ceramic transducer includes a tubular body and a metal electrode unit. The tubular body is made of a piezoelectric ceramic material, and includes an inner surrounding surface surrounding an extending central axis thereof and defining an axial through hole, an outer surrounding surface surrounding the inner surrounding surface, and a connecting surface connected between the inner surrounding surface and the outer surrounding surface. Any tangent plane of the connecting surface of the tubular body is not perpendicular to the extending central axis. The metal electrode unit includes a first layer formed on the inner surrounding surface, and a second layer formed on the outer surrounding surface.

A vibration apparatus includes a vibration device. The vibration device includes a vibration portion including a piezoelectric material, a first electrode portion at a first surface of the vibration portion and configured as a plurality of circular patterns, and a second electrode portion at a second surface different from the first surface of the vibration portion and configured as a single electrode, and the vibration device generates an ultrasound wave.

A vibration apparatus includes a vibration device. The vibration device includes a vibration portion including a piezoelectric material, a first electrode portion at a first surface of the vibration portion and configured as a plurality of circular patterns, and a second electrode portion at a second surface different from the first surface of the vibration portion and configured as a single electrode, and the vibration device generates an ultrasound wave.

A piezoelectric device has a layered structure in which at least a first electrode, a plastic layer, an orientation control layer, a piezoelectric layer, and a second electrode are stacked, wherein the orientation control layer is amorphous, and the piezoelectric layer with a thickness of 20 nm to 250 nm is provided over the orientation control layer, the piezoelectric layer having a wurtzite crystal structure, and wherein the orientation control layer and the piezoelectric layer are provided between the first electrode and the second electrode.

The present invention is directed to a method for manufacturing an ultrasonic fingerprint sensor by using a nanorod structure, the method including: a conductive mold generating step of generating a plurality of rod generation holes; a nanorod generating step of generating nanorods by filling the plurality of rod generation holes with a nano-piezoelectric material; a side electrode generation portion marking step of marking side electrode generation portions; a conductive mold etching step of generating nanorods and side electrodes by performing primary etching on the conductive mold; an insulating material filling step of filling portions with an insulating material; a lower electrode forming step of performing secondary etching and forming lower electrodes; a dummy substrate bonding step of bonding a dummy substrate to a surface on which the lower electrodes are formed; and an upper electrode forming step of removing the conductive substrate base and forming upper electrodes.

A cartridge for a high intensity focused ultrasound (HIFU) device and a piezoelectric linear motor are disclosed. By using the cartridge for a HIFU device according to the present invention, a transducer module is coupled to a piezoelectric linear motor driveable in water and embedded in the cartridge, heat generated when a conventional step motor is driven is fundamentally removed, an additional cooling fan is not needed, ultra-low power consumption and ultra-precise transfer can be realized, and thus an effective procedure can be performed. A skin beauty device may include ultrasound and high frequency units, apply a high frequency to a skin to be treated so as to crack a stratum corneum, and apply ultrasound to the skin to be treated, and thus a medicament drug can easily penetrate the treated skin. In addition, the piezoelectric linear motor in which a piezoelectric actuator and a moving shaft are stably coupled is provided.

An electric current based on electric charge produced on the piezoelectric body changes by going through a first path, a second path, a third path, and a fourth path in this order. On the first path, the electric current becomes larger as the voltage becomes higher. On the second path, the electric current becomes smaller as the voltage becomes higher. On the third path, the electric current becomes larger as the voltage becomes higher. On the fourth path, the electric current becomes smaller as the voltage becomes higher.

An electric current based on electric charge produced on the piezoelectric body changes by going through a first path, a second path, a third path, and a fourth path in this order. On the first path, the electric current becomes larger as the voltage becomes higher. On the second path, the electric current becomes smaller as the voltage becomes higher. On the third path, the electric current becomes larger as the voltage becomes higher. On the fourth path, the electric current becomes smaller as the voltage becomes higher.