IBULe Photonics Co.

Yeonsu gu, South Korea

IBULe Photonics Co.

Yeonsu gu, South Korea
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Park N.,Korea Basic Science Institute | Kang H.,Sungkyunkwan University | Park J.,Korea Basic Science Institute | Lee Y.,Korea Basic Science Institute | And 5 more authors.
ACS Nano | Year: 2015

The effect of a ferroelectric polarization field on the charge transport in a two-dimensional (2D) material was examined using a graphene monolayer on a hexagonal boron nitride (hBN) field-effect transistor (FET) fabricated using a ferroelectric single-crystal substrate, (1-x)[Pb(Mg1/3Nb2/3)O3]-x[PbTiO3] (PMN-PT). In this configuration, the intrinsic properties of graphene were preserved with the use of an hBN flake, and the influence of the polarization field from PMN-PT could be distinguished. During a wide-range gate-voltage (VG) sweep, a sharp inversion of the spontaneous polarization affected the graphene channel conductance asymmetrically as well as an antihysteretic behavior. Additionally, a transition from antihysteresis to normal ferroelectric hysteresis occurred, depending on the VG sweep range relative to the ferroelectric coercive field. We developed a model to interpret the complex coupling among antihysteresis, current saturation, and sudden conductance variation in relation with the ferroelectric switching and the polarization-assisted charge trapping, which can be generalized to explain the combination of 2D structured materials with ferroelectrics. © 2015 American Chemical Society.


Yu P.,InfraTec GmbH | Ji Y.,InfraTec GmbH | Neumann N.,InfraTec GmbH | Lee S.-G.,IBULe Photonics Co. | And 2 more authors.
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control | Year: 2012

The suitability for use in pyroelectric detectors of single-crystalline doped and undoped lead indium niobate- lead magnesium niobate-lead titanate was tested and compared with high-quality Mn-doped lead magnesium niobate- lead titanate and standard lithium tantalate. Pyroelectric and dielectric measurements confirmed an increased processing and operating temperature range because of the higher phase transitions of lead indium niobate-lead magnesium niobate-lead titanate. Pyroelectric coefficients of 705 to 770 μC/m 2K were obtained with doped and undoped lead indium niobate-lead magnesium niobate-lead titanate, which are about 70% to 80% of the pyroelectric coefficient of lead magnesium niobate-lead titanate but 4 times higher than standard lithium tantalate. Manganese doping has been proved as a solution to decrease the dielectric loss of lead magnesium niobate-lead titanate and it also works well for lead indium niobate-lead magnesium niobate-lead titanate. An outstanding specific detectivity D* of about 1.1 · 10 9 cm-Hz 1/2/W was achieved at a frequency of 2 Hz for Mn-doped lead magnesium niobate-based detectors. © 2012 IEEE.


PubMed | University of Southern California, Dongguk University and IBULE Photonics Co.
Type: | Journal: Sensors and actuators. A, Physical | Year: 2015

A transducer with an angled and focused aperture for intravascular ultrasound imaging has been developed. The acoustic stack for the angled-focused transducer was made of PMN-PT single crystal with one matching layer, one protective coating layer, and a highly damped backing layer. It was then press-focused to a desired focal length and inserted into a thin needle housing with an angled tip. A transducer with an angled and unfocused aperture was also made, following the same fabrication procedure, to compare the performance of the two transducers. The focused and unfocused transducers were tested to measure their center frequencies, bandwidths, and spatial resolutions. Lateral resolution of the angled-focused transducer (AFT) improved more than two times compared to that of the angled-unfocused transducer (AUT). A tissue-mimicking phantom in water and a rabbit aorta tissue sample in rabbit blood were scanned using AFT and AUT. Imaging with AFT offered improved contrast, over imaging with AUT, of the tissue-mimicking phantom and the rabbit aorta tissue sample by 23 dB and 8 dB, respectively. The results show that AFT has strong potential to provide morphological and pathological information of coronary arteries with high resolution and high contrast.


Rajaram Patil D.,Seoul National University | Chai Y.,Seoul National University | Kambale R.C.,Korea Institute of Materials Science | Jeon B.-G.,Seoul National University | And 11 more authors.
Applied Physics Letters | Year: 2013

Giant transverse magnetoelectric voltage coefficients |̄α E|= 751 and 305 V/cmOe at two electromechanical antiresonance frequencies are found in the symmetric metglas/[011]-oriented 0.7Pb(Mg 1/3Nb2/3)O3-0.3PbTiO3 crystal/metglas laminate. Unique torsional and diagonal vibration modes are identified to be responsible for those giant |̄αE|values. Moreover, ̄αE is found to be anisotropic depending on the in-plane magnetic field directions, making the piezoelectrics with anisotropic planar piezoelectricity potentially useful base materials for multi-frequency, phase-sensitive magnetoelectric devices. © 2013 American Institute of Physics.


Yang J.,Seoul National University | Lee S.,Ibule Photonics Inc. | Kim J.,Seoul National University
Electronics Letters | Year: 2014

The optimal capacitive load condition is derived for a passive bridge rectifier to harvest the maximum amount of energy when a piezoelectric generator (PG) receives a single vibration pulse (e.g. a button press). When the PG is modelled as a current pulse generator with an internal shunt capacitance (C P), it is shown that an ideal bridge rectifier collects the maximum energy when its output capacitance is set to 3·CP. The impacts of the nonzero turn-on voltage and on-resistance of the diodes are also discussed. The experimental results with a 300 mm2 lead magnesium niobate-lead titanate PG and a Schottky-bridge rectifier with 0.22 V turn-on voltage demonstrate that the maximum energy transfer occurs at a capacitance ratio of 3.3, collecting 117 μJ from a single button press. © The Institution of Engineering and Technology 2014.


Hwang G.-T.,Korea Advanced Institute of Science and Technology | Park H.,Yonsei University | Lee J.-H.,IBULe Photonics Co. | Oh S.,Korea Advanced Institute of Science and Technology | And 9 more authors.
Advanced Materials | Year: 2014

A flexible single-crystalline PMN-PT piezoelectric energy harvester is demonstrated to achieve a self-powered artificial cardiac pacemaker. The energy-harvesting device generates a short-circuit current of 0.223 mA and an open-circuit voltage of 8.2 V, which are enough not only to meet the standard for charging commercial batteries but also for stimulating the heart without an external power source. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Trademark
IBULE PHOTONICS Co. | Date: 2010-12-24

Digital cameras; infrared cameras; acceleration sensors; distance measuring apparatus; range finders; metal detectors for industrial or military purposes; resonators; probes for scientific purposes, namely, for testing printed circuit boards; measuring instruments, namely, saccharometers; testing apparatus for testing printed circuit boards; diagnostic apparatus for printed circuit boards; marine depth finders; echo sounding apparatus and machines; water level indicators; automatic liquid-level control machines and instruments; gyrometers; precision measuring apparatus for printed circuit boards; precision measuring machines for printed circuit boards; measuring instruments for printed circuit boards; ultrasonic thickness gauges for animals skins for non-medical use; electronic ultrasonic test equipment, namely, thickness measurers for leather; ultrasonic heat sensors; acoustic sound alarms; alarms for the detection of inflammable gases; dry cells; electric batteries; self-charging batteries; batteries that charge wirelessly; frequency converter for actuators; portable communications apparatus, namely, cellular telephones; blank optical discs; blank optical discs for recording hologram images; computer software for detecting flaws in printed circuit boards; computer software programs for detecting flaws in printed circuit boards; roentgen cameras, not for medical purposes; lasers, not for medical purposes; hydrophone machines and apparatus for printed circuit boards; operating system programs; sonars; echo sounders; sound locating instruments, namely, echo sounders; computer application software for cellular telephones for detecting flaws in printed circuit boards; electron microscopes; ultrasonic echo sounders; ultrasonic flaw detectors; ultrasonic sensors; ultrasonic sensor probes, not for medical purposes; semi-conductor memories; semi-conductor memory units; semi-conductor elements, namely, memory units; structured semi-conductor wafers; silicon wafers; electronic circuit boards; electronic integrated circuits; integrated circuits; integrated circuit modules; circuit boards; protective helmets; protective helmets for sports; motorcycle helmets. Rigid and flexible endoscopes for medical use; high frequency electromagnetic therapy apparatus; apparatus for the treatment of deafness, namely, hearing aids; esthetic massage apparatus; radiotherapy apparatus; heartbeat measuring apparatus; electrocardiographs; roentgen apparatus for medical purposes, namely, monitoring vital signs of patients; massage apparatus for medical purposes; radiological apparatus for medical purposes; medical hearing instruments and parts of such devices; ultrasonic diagnostic apparatus for medical purposes; probes for medical purposes; mobile monitoring scanners for monitoring vital signs of patients; apparatus for clinical diagnosis; ultraviolet radiator units for therapeutic purposes; low frequency electric therapy apparatus; infrared radiator units for therapeutic purposes; electric hearing aids; galvanic therapeutic appliances for the treatment of heart and brain disease; stethoscopes; ultrasonic short wave therapy machines and apparatus; ultrasonic therapy machines and apparatus; X-ray appliances for dental and medical use; devices for measuring blood sugar; arterial blood pressure measuring apparatus; blood testing apparatus; apparatus for blood analysis; ultrasonic probes for medical purposes; ultrasonic medical diagnostic apparatus.


Trademark
Ibule Photonics Co. | Date: 2013-10-20

Clocks; Parts for watches; Wrist watches.


Trademark
IBULE PHOTONICS Co. | Date: 2012-12-11

Digital cameras; infrared cameras; acceleration sensors; distance measuring apparatus; range finders; metal detectors for industrial or military purposes; resonators; probes for scientific purposes, namely, for testing printed circuit boards; measuring instruments, namely, saccharometers; testing apparatus for testing printed circuit boards; diagnostic apparatus for printed circuit boards; marine depth finders; echo sounding apparatus and machines; water level indicators; automatic liquid-level control machines and instruments; gyrometers; precision measuring apparatus for printed circuit boards; precision measuring machines for printed circuit boards; measuring instruments for printed circuit boards; ultrasonic thickness gauges for animals skins for non-medical use; electronic ultrasonic test equipment, namely, thickness measurers for leather; ultrasonic heat sensors; acoustic sound alarms; alarms for the detection of inflammable gases; dry cells; electric batteries; self-charging batteries; batteries that charge wirelessly; electroacoustic transducers; headphones; audio speakers; panel loud speakers; microphones; frequency converter for actuators; wireless communication device for voice transmission; apparatus for wireless transmission of acoustic information; earphones; microphones for telecommunication apparatus; portable communications apparatus, namely, cellular telephones; roentgen cameras, not for medical purposes; lasers, not for medical purposes; hydrophone machines and apparatus for printed circuit boards; sonars; echo sounders; sound locating instruments, namely, echo sounders; electron microscopes; ultrasonic echo sounders; ultrasonic flaw detectors; ultrasonic sensors; ultrasonic sensor probes, not for medical purposes; protective helmets; protective helmets for sports; motorcycle helmets. Rigid and flexible endoscopes for medical use; high frequency electromagnetic therapy apparatus; apparatus for the treatment of deafness, namely, hearing aids; esthetic massage apparatus; radiotherapy apparatus; heartbeat measuring apparatus; electrocardiographs; roentgen apparatus for medical purposes, namely, monitoring vital signs of patients; massage apparatus for medical purposes; radiological apparatus for medical purposes; medical hearing instruments and parts of such devices; ultrasonic diagnostic apparatus for medical purposes; probes for medical purposes; mobile monitoring scanners for monitoring vital signs of patients; apparatus for clinical diagnosis; ultraviolet radiator units for therapeutic purposes; low frequency electric therapy apparatus; infrared radiator units for therapeutic purposes; electric hearing aids; galvanic therapeutic appliances for the treatment of heart and brain disease; stethoscopes; ultrasonic short wave therapy machines and apparatus; ultrasonic therapy machines and apparatus; X-ray appliances for dental and medical use; devices for measuring blood sugar; arterial blood pressure measuring apparatus; blood testing apparatus; apparatus for blood analysis; ultrasonic probes for medical purposes; ultrasonic medical diagnostic apparatus.


PubMed | IBULE Photonics Co.
Type: Journal Article | Journal: ACS nano | Year: 2015

The effect of a ferroelectric polarization field on the charge transport in a two-dimensional (2D) material was examined using a graphene monolayer on a hexagonal boron nitride (hBN) field-effect transistor (FET) fabricated using a ferroelectric single-crystal substrate, (1-x)[Pb(Mg1/3Nb2/3)O3]-x[PbTiO3] (PMN-PT). In this configuration, the intrinsic properties of graphene were preserved with the use of an hBN flake, and the influence of the polarization field from PMN-PT could be distinguished. During a wide-range gate-voltage (VG) sweep, a sharp inversion of the spontaneous polarization affected the graphene channel conductance asymmetrically as well as an antihysteretic behavior. Additionally, a transition from antihysteresis to normal ferroelectric hysteresis occurred, depending on the V(G) sweep range relative to the ferroelectric coercive field. We developed a model to interpret the complex coupling among antihysteresis, current saturation, and sudden conductance variation in relation with the ferroelectric switching and the polarization-assisted charge trapping, which can be generalized to explain the combination of 2D structured materials with ferroelectrics.

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