Pohang University of Science and Technology Foundation

Wonkyu Moon

Haksue Lee

Moojin Kim

Sang Hoon Lee

Daesil Kang

Sungjoon Choi

Wankyun Chung

A sound sensor, a hydrophone including the sound sensor, and a pressure balancing device for using for the hydrophone are provided. The hydrophone includes: a sensor including a sensing part and a pressure balancing part; a printed circuit board (PCB) that is electrically connected to the sensor; a case that houses the sensor and the PCB and that has an opening at one side thereof; an elastic membrane that covers the opening of the case; and a signal line that is electrically connected to the PCB to be extended to the outside of the case. The pressure balancing part includes a diaphragm of a thin film and a support that supports the diaphragm. A pressure balancing hole is formed at one side of the pressure balancing part, and at the inside of the pressure balancing part, a channel that is connected to the pressure balancing hole is formed, and a compressible gas is filled in the channel.

Hydrophone and pressure balancing device for using for hydrophone

An area-variable type capacitive displacement sensor includes: a stationary element; a movable element; an elastic member for providing a force biasing one of the stationary element and the movable member towards a remaining one thereof in a direction perpendicular to a driving direction so that the stationary element and the movable member are maintained in close contact with each other; a power supply; and a signal detecting circuit. The sensor further includes a guide means for correcting an initial alignment error and reducing an operation alignment error between the stationary element and the movable element.

Area-variable type capacitive displacement sensor having mechanical guide

A multiple resonances type ultrasonic transducer for a ranging measurement with high directionality using a parametric transmitting array in air, includes an ultrasonic actuator unit formed with a regularly mixing array of first unit actuators having a resonance frequency of fand second unit actuators having a resonance frequency of fThe ultrasonic actuator unit generates a difference frequency wave (f=f&#x2212;f) with high directionality by forming a parametric transmitting array in air through generating two ultrasonic waves with high pressure in air. Further, the transducer includes an ultrasonic sensor unit formed with one or more unit sensors having a resonance frequency of the difference frequency (f=f&#x2212;f), for sensing a reflected ultrasonic pulse signal from a target.

Ultrasonic transducer for ranging measurement with high directionality using parametric transmitting array in air and a method for manufacturing same

A probe of a scanning probe microscope having a sharp tip and an increased electric characteristic by fabricating a planar type of field effect transistor and manufacturing a conductive carbon nanotube on the planar type field effect transistor. To achieve this, the present invention provides a method for fabricating a probe having a field effect transistor channel structure including fabricating a field effect transistor, making preparations for growing a carbon nanotube at a top portion of a gate electrode of the field effect transistor, and generating the carbon nanotube at the top portion of the gate electrode of the field effect transistor.

Method of fabricating a probe having a field effect transistor channel structure

A contact-type electric capacitive displacement sensor includes a stationary element having a stationary plate, a stationary conductive pattern formed on the stationary plate and an insulation film coated on the stationary plate and a displaceable element having a displaceable plate, a displaceable conductive pattern formed on the displaceable plate and an insulation film coated on the displaceable plate. The stationary and the displaceable conductive patterns have a cyclic pattern of conductor to thereby produce a variation of capacitance therebetween when moving relative to each other.

Contact-type electric capacitive displacement sensor

An ultrasonic ranging method for measuring a distance to an object in an air includes the steps of generating a first and a second primary ultrasonic waves having a frequency fand f, respectively, transmitting the first and the second primary ultrasonic waves in a same direction, wherein a secondary ultrasonic wave having a frequency corresponding to the difference of two frequencies f=f&#x2212;fis created by a nonlinear property of the air and radiated to the object, detecting an echo pulse of the secondary ultrasonic wave reflected from the object, and measuring the distance to the object based on a propagation time of the secondary wave.

Ultrasonic ranging system and method thereof in air by using parametric array

A capacitive motion sensor includes a primary plate including a primary pattern replicated periodically, a secondary plate including a plurality of pattern regions with an insulated region inserted there between, wherein each of the pattern regions has a secondary pattern replicated periodically, a signal source for sending a plate input signal to the primary plate, and a displacement measuring unit for receiving a plurality of plate output signals from the secondary plate to measure a displacement of a moving one of the plates with respect to the other one of the plates. The primary plate is arranged in parallel with the secondary plate in such a manner that the primary pattern is confronted with the secondary pattern and the pattern regions of the secondary plate are arranged in a two-dimensional array.

Growing community of inventors

Kyungsangbuk-do, South Korea

Wonkyu Moon