• Journal of Sensor Science and Technology
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• v.28 no.2
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• pp.133-138
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• 2019

The a-InGaZnO (a-IGZO) thin film transistor (TFT) has the advantages of larger mobility than that of amorphous silicon TFTs, acceptable reliability and uniformity over a large area, and low process cost. A capacitive-type touch sensor was studied with an a-IGZO TFT that can be used on the front side of a display due to its transparency. A capacitive sensor detects changes of capacitance between the surface of the finger and the sensor electrode. The capacitance varies according to the distance between the sensor plate and the touching or non-touching of the sensing electrode. A capacitive touch sensor using only one a-IGZO TFT was developed with the reduction of two bus lines, which made it easy to reduce the pixel pitch. The proposed sensor circuit maintained the amplification performance, which was investigated for various drive conditions.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.1
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• pp.58-63
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• 2010

In this paper, we proposed a wearable respiration measurement system with textile capacitive pressure sensor. Belt typed textile capacitive pressure sensor approach of respiration measurement, from which respiration signatures and rates can be derived in real-time for long-term monitoring, are presented. Belt typed textile capacitive pressure sensor has been developed for this measurement system. the distance change of two plates by the pressure of motion has been used for the respiration measurement in chest area. Respiration rates measured with the textile capacitive pressure sensor was compared with standard techniques on 8 human subjects. Accurate measurement of respiration rate with developed sensor system is shown. The data from the method comparison study is used to confirm theoretical estimates of change in capacitance by the distance change. The current version of respiratory rate detection system using textile capacitive pressure sensor can successfully measure respiration rate. It showed upper limit agreement of $3.7997{\times}10^{-7}$ RPM, and lower limit of agreement of $-3.8428{\times}10^{-7}$ RPM in Bland-Altman plot. From all subject, high correlation were shown(p<0.0001). The proposed measurement method could be used to monitor unconscious persons, avoiding the need to apply electrodes to the directly skin or other sensors in the correct position and to wire the subject to the monitor. Monitoring respiration using textile capacitive pressure sensor offers a promising possibility of convenient measurement of respiration rates. Especially, this technology offers a potentially inexpensive implementation that could extend applications to consumer home-healthcare and mobile-healthcare products. Further advances in the sensor design, system design and signal processing can increase the range and quality of the rate-finding, broadening the potential application areas of this technology.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.12a
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• pp.639-645
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• 1999

• Journal of Sensor Science and Technology
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• v.7 no.2
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• pp.90-96
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• 1998

Non-contacting capacitive sensors, based on principle of the cross capacitor, for measuring small displacement less than $1.95{\pm}0.5\;mm$ have been fabricated and characterized. To overcome disadvantages of the existed capacitive sensors with 2-electrodes and 3-electrodes, the new sensor is consisted of 4-electrodes which are formed two electrode(high, low) and 2 guard electrodes on a sapphire plate with diameter 17 mm and thickness 0.7 mm, and are symmetrically situated with a constant gap of 0.2 mm between the electrodes. This sensor can be used for measuring both metallic and non-metallic target without ground connection, and is evaluated to the correlation coefficient of 0.9987 for the range of $1.95{\pm}0.5\;mm$ and that of 0.9995 for $1.95{\pm}0.25\;mm$ range.

• Journal of Sensor Science and Technology
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• v.25 no.5
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• pp.310-319
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• 2016

Three types of gap sensors, a capacitive gap sensor, an eddy current gap sensor, and a Hall effect gap sensor are described and evaluated through experiments for the purpose of precise gap sensing for micrometer scale movement, and a novel type of differential hall effect gap sensor is proposed. Each gap sensor is analyzed in terms of resolution and environment dependency including temperature dependency. Furthermore, a transport system for AMOLED deposition is introduced as a typical application of gap sensors, which are recently receiving considerable attention. Based on the analyses, the proposed differential Hall effect gap sensor is found to be the most suitable gap sensor for precise gap sensing, especially for application to a transport system for AMOLED deposition. The sensor shows resolution of $0.63mV/{\mu}m$ for the overall range of the gap from 0 mm to 2.5 mm, temperature dependency of $3{\mu}m/^{\circ}C$ from $20^{\circ}C$ to $30^{\circ}C$, and a monotonic characteristic for the gap between the sensor and the target.

• Journal of Sensor Science and Technology
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• v.32 no.1
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• pp.22-30
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• 2023

Innovative and advanced technologies, including robots, augmented reality, virtual reality, the Internet of Things, and wearable medical equipment, have largely emerged as a result of the rapid evolution of modern society. For these applications, pressure monitoring is essential and pressure sensors have attracted considerable interest. To improve the sensor performance, several new designs of pressure sensors have been researched based on resistive, capacitive, piezoelectric, optical, and triboelectric types. In particular, optical pressure sensors have been actively studied owing to their advantages, such as robustness to noise and remote sensing capability. Herein, a review of recent research on optical pressure sensors with self-powered sensing, remote sensing, high spatial resolution, and multimodal sensing capabilities is presented from the viewpoints of design, fabrication, and signal processing.

• Journal of Sensor Science and Technology
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• v.14 no.1
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• pp.28-32
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• 2005

In this paper, a CMOS integrated detection circuit for capacitive type fingerprint sensor signal processing is described. We designed a detection circuit of charge-sharing sensing scheme. The proposed detection circuit increases the voltage difference between a ridge and valley. The test chip is composed of $160{\times}192$ array sensing cells (12 by $12.7{\;}mm^{2}$). The chip was fabricated on a 0.35 m standard CMOS process. Measured difference voltage between a ridge and valley was 0.95 V.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.121-126
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• 2005

This paper describes the attributes, performance and development status of a high performance capacitive torque sensor intended for use in a electric power steering (EPS) system. The EPS system is composed of torque sensor, ECU, motor, gears and etc. Among the elements, torque sensor in the steering column is one of the core technologies. The new capacitive torque sensor in this paper is developed differently from working principle and mechanical structure compare to extant torque sensors in market and patent. Based on the result of numerical analysis, a experimental equipment is made which is composed of a test jig and a capacitive sensor and validity of numerical analysis and feasibility of the torque sensor are verified.

• Progress in Superconductivity and Cryogenics
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• v.23 no.4
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• pp.6-9
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• 2021

Superconducting coplanar waveguide (SCPW) resonators with high quality (Q) factor are widely used for developing quantum sensors and quantum information processors. Here we conducted numerical simulations of SCPW resonators to investigate the relationship between the Q factor and the coupling capacitance of the resonator. Varying the geometrical shape of both ends and coupling parameters of the SCPW resonator resulted in a change of the coupling capacitances and the Q factor as well. Our calculation results indicate that the performance of the SCPW resonator is highly sensitive to the capacitive coupling and searching for an optimal coupling condition would be crucial for developing high-performance SCPW resonator.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1277-1278
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• 2007

본 논문에서는 폴리이미드를 감습재로 한 정전용량형 습도 센서의 상용화 연구 결과를 보고한다. 유리 기판상에 제작된 용량형 습도센서는 감도 0.338pF%RH, 히스테리시스 1.7%.인 특성을 나타내었다.