Korea Institute of Science and Technology

Seok Jin Yoon

Chong Yun Kang

Ji Won Choi

Hyun Jai Kim

Jin Sang Kim

Hyung Jin Jung

Seung Hyub Baek

Piotr Vasiljev

Hyun Cheol Song

Young Ho Do

Hi Gyu Moon

Ho Won Jang

Hyun Jin Kim

Hyun Phill Ko

Won Kook Choi

Ji-Won Choi

Seong Keun Kim

Sung Hun Sim

Sang O Yoon

Young Soo Yoon

Tetsuro Nakamura

Mitsuru Itoh

Woo-Suk Jung

Beomjin Kwon

Shin Ik Kim

Dae Yong Jeong

Dong Kyun Lee

Hyeung Kwon Choi

Kyong Y Kim

Yoshiyouki Inaguma

Kucheiko Sergei

Disclosed is a curved piezoelectric device maximizing an electrical potential of the piezoelectric material corresponding to an external mechanical stress. The curved piezoelectric device includes: a curved substrate; and a piezoelectric material provided on one surface or both surfaces of the curved substrate, wherein when a stress is applied, a neutral plane in which a compressive stress and a tensile stress are balanced is located in the curved substrate, wherein the location of the neutral plane is determined by yand yof Equation 1 or 2 below, and wherein the location of the neutral plane is controllable by adjusting a thickness (d), a sectional area (A) and a Young's modulus (E) of each of the curved substrate and the piezoelectric material: wherein 

Curved piezoelectric device

The present disclosure provides a gas sensor including: a substrate; an electrode formed on the substrate; and a gas-sensing layer formed on the electrode, wherein the gas-sensing layer is a self-heating nanocolumnar structure having nanocolumns formed on the electrode and inclined with respect to the electrode with an angle of 60-89&#xb0; and gas diffusion pores formed between the nanocolumns. The gas sensor according to the present disclosure requires no additional heater since it self-heats owing to the nanocolumnar structure and exhibits superior gas sensitivity even when no heat is applied from outside. Also, it can be mounted on mobile devices such as mobile phones because it consumes less power.

Low power consumption type gas sensor and method for manufacturing the same

Provided are a method of manufacturing a flexible piezoelectric energy harvesting device using a piezoelectric composite, and a flexible piezoelectric energy harvesting device manufactured by the same. The method of manufacturing the flexible piezoelectric energy harvesting device includes: forming a first electrode layer on a first flexible substrate; spin-coating a piezoelectric composite layer on the first electrode layer, wherein the piezoelectric composite layer is produced by mixing piezoelectric powder with polymer; performing heat treatment on the piezoelectric composite layer to harden the piezoelectric composite layer; and bonding a second flexible substrate with a second electrode layer on the hardened piezoelectric composite layer. Therefore, it is possible to simplify a manufacturing process and manufacture a high-performance flexible piezoelectric energy harvesting device having various sizes and patterns.

Method of manufacturing flexible piezoelectric energy harvesting device

Provided is an oxide electronic device, including: an oxide substrate; an oxide thin film layer formed on the oxide substrate and containing an oxide that is heterogeneous with respect to the oxide substrate; and a ferroelectric layer formed on the oxide thin film layer and controlling electric conductivity of two-dimensional electron gas (2DEG) generated at an interface between the oxide substrate and the oxide thin film layer. Provided also is a method for manufacturing an oxide electronic device, including: depositing, on an oxide substrate, an oxide that is heterogeneous with respect to the oxide substrate to form an oxide thin film layer; and forming a ferroelectric layer on the oxide thin film layer, wherein the ferroelectric layer controls electric conductivity of 2DEG generated at an interface between the oxide substrate and the oxide thin film layer.

Oxide electronic device and method for manufacturing the same

Provided is a method of fabricating an oxide thin film device using laser lift-off and an oxide thin film device fabricated by the same. The method includes: forming an oxide thin film on a growth substrate; bonding a temporary substrate on the oxide thin film; irradiating laser onto the growth substrate to separate the oxide thin film on which the temporary substrate has been bonded from the growth substrate; bonding a device substrate on the oxide thin film on which the temporary substrate has been bonded; and forming an upper electrode film on the oxide thin film. Therefore, it is possible to overcome problems caused by a defective layer by transferring an oxide thin film transferred on a polymer-based temporary substrate onto a device substrate, without using an interface on which a defective layer formed due to oxygen diffusion upon laser lift-off is formed.

Method of fabricating oxide thin film device using laser lift-off and oxide thin film device fabricated by the same

Disclosed are a high-sensitivity transparent gas sensor and a method for manufacturing the same. The transparent gas sensor includes a transparent substrate, a transparent electrode formed on the transparent substrate and a transparent gas-sensing layer formed on the transparent electrode. The transparent gas-sensing layer has a nanocolumnar structure having nanocolumns formed on the transparent electrode and gas diffusion pores formed between the nanocolumns.

High-sensitivity transparent gas sensor and method for manufacturing the same

The present invention relates to a piezoelectric linear motor that can make relatively low abrasion and accurate linear movement since stationary AC voltages are applied to two piezoelectric elements with a phase difference. The present invention provides a piezoelectric linear motor, comprising: a piezoelectric substrate having a first piezoelectric element and a second piezoelectric element, wherein AC voltages are applied to the first and second piezoelectric elements with a phase difference; a metallic elastic body having first and second elastic bodies coupled to the piezoelectric elements and a central protrusion protruded at the central portion connecting the first and second elastic bodies, wherein the central protrusion oscillates elliptically during an application of the voltage; and a mover brought into contact with the central protrusion of the metallic elastic body for a linear movement, and wherein the movement of the mover is orthogonal to the central protrusion.

Piezo electric linear motor

A piezoelectric linear motor for amplifying the change in at least one dimension of a piezoelectric material is disclosed. A shaft is connected axial-movably to a piezoelectric actuator. The actuator includes a piezoelectric ceramic that expands or contracts in response to an applied voltage. The expansion or contraction of the piezoelectric ceramic is amplified by converting the displacement due to expansion/contraction into a greater displacement of a top plate to which the shaft is coupled. The greater displacement is, for instance, by causing the expansion/contraction of the piezoelectric ceramic into a convex or concave bending of a complex of which the piezoelectric ceramic is a part. In a preferred embodiment the base plate is attached to the piezoelectric ceramic, a slanted plate conically extending from the base plate, and a top plate formed at the center of the slanted plate to form an assembly that changes its curvature to amplify the displacement.

Piezoelectric linear motor with displacement amplifying means

The present invention relates to a linear motor which draws its operating power from ultrasonic vibration above the frequency of 20 kHz which is generated by piezoelectric ceramic. More particularly, the invention relates to a linear piezoelectric ultrasonic motor which linearly operates a slider due to a frictional force generated by applying sinusoidal electric field with a 90 degree phase difference to a pair of piezoelectric ceramic. This causes an elliptical mechanical vibration on a shaking beam which is connected to the piezoelectric ceramic.

Linear piezoelectric ultrasonic motor

A ceramic chip antenna, which has a small size and a broad bandwidth, is provided. The ceramic chip antenna consists of a ceramic body with cuboid shape, a conductor wound helically inside the ceramic body, and signal-feed terminal formed on a surface of the ceramic body. The ceramic chip antenna with a helical conductor patterns formed in a symmetrical dipole shape is provided, which has a high gain value and excellent radiation characteristics. Also, it can be built-in inside a mobile terminal due to its small size. The ceramic chip antenna according to the present invention can have a broad bandwidth that satisfies the variable frequency of the present mobile communication system.

Ceramic chip antenna

The present invention relates to a ring-type piezoelectric ultrasonic motor that is different from the electro-magnetically driven conventional motors and that has applications in robots and automation equipments. More specifically, the present invention relates to a ring-type piezoelectric ultrasonic motor that is driven by a frictional force between rotor and stator, and stator is produced a mechanical displacement by a piezoelectric ceramics applying an alternate electric field with an ultrasonic frequency (above kHz).

Ring-type piezoelectric ultrasonic motor

A monoblock dielectric duplexer comprises resonant holes. Conductive electrodes and couplers are formed on one side of the dielectric block, whose other sides are covered with a conductive material. The conductive electrodes in a transmit-filtering portion are formed in an inter-digitating manner while the conductive electrodes in receive-filtering portion are formed to be of pad-shape. In the duplexer, capacitances of capacitors comprised of the conductive electrodes are easily and accurately set to desired values by determining the number and/or the lengths of fingers that the inter-digitating electrodes have.

Monoblock dielectric duplexer

An electrical or electronic device and a thin-film type battery are vertically integrated and interconnected for reducing the area occupied thereby, enabling a higher degree of device integration and simplifying their fabrication. An insulating layer is formed on the device, with vertical conductors extending respectively from a pair of terminals of the device through the insulating layer. Electrode conductors are formed on the insulating layer in contact with the respective vertical conductors and serve as the cathode and anode electrodes of a thin-film battery fabricated thereon.

Method for making electrical and electronic devices with vertically integrated and interconnected thin-film type battery

This invention provides a composition of high frequency dielectric ceramics represented by the following formula:

High frequency dielectric material

The present invention provides compositions of high frequency dielectric ceramics represented by the following formula:

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Seoul, South Korea

Seok Jin Yoon