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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Sensor Science and Technology
Journal Basic Information
Journal DOI :
The Korean Sensors Society
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Volume & Issues
Volume 24, Issue 6 - Nov 2015
Volume 24, Issue 5 - Sep 2015
Volume 24, Issue 4 - Jul 2015
Volume 24, Issue 3 - May 2015
Volume 24, Issue 2 - Mar 2015
Volume 24, Issue 1 - Jan 2015
Selecting the target year
Ag Electrode Strain Sensor Fabrication Using Laser Direct Writing Process
Kim, Hyeonseok ; Shin, Jaeho ; Hong, Sukjoon ; Ko, Seung Hwan ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 215~218
DOI : 10.5369/JSST.2015.24.4.215
As several innovative technologies for flexible electric devices are being realized, demand for in-situ strain monitoring for flexible electric devices is being emphasized. Because flexible devices are commonly influenced by substrate strain, suitable strain sensors for flexible devices are essential for the sophisticated maneuvering of flexible devices. In this study, a flexible strain sensor based on an Ag electrode is prepared on a polyimide substrate using the LDW (laser direct writing) process. In this process, first, the Ag nanoparticles are coated on the substrate and selectively sintered using a focused laser. Because of the advantages of the LDW process (such as being mask-less, using low temperatures, and having non-vacuum characteristics), the entire fabrication process has been dramatically simplified; as a final outcome, a highly reliable strain sensor has been fabricated. Using this strain sensor, various strain conditions that arise from different bending radii can be detected by measuring real-time electrical signals.
Transparent Conducting Multilayer Electrode (GTO/Ag/GTO) Prepared by Radio-Frequency Sputtering for Organic Photovoltaic's Cells
Pandey, Rina ; Kim, Jung Hyuk ; Hwang, Do Kyung ; Choi, Won Kook ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 219~223
DOI : 10.5369/JSST.2015.24.4.219
Indium free consisting of three alternating layers GTO/Ag/GTO has been fabricated by radio-frequency (RF) sputtering for the applications as transparent conducting electrodes and the structural, electrical and optical properties of the gallium tin oxide (GTO) films were carefully studied. The gallium tin oxide thin films deposited at room temperature are found to have an amorphous structure. Hall Effect measurements show a strong influence on the conductivity type where it changed from n-type to p-type at
. GTO/Ag/GTO multilayer structured electrode with a few nm of Ag layer embedded is fabricated and show the optical transmittance of 86.48% in the visible range (
= 380~770 nm) and quite low electrical resistivity of
. The resultant power conversion efficiency of 2.60% of the multilayer based OPV (GAG) is lower than that of the reference commercial ITO. GTO/Ag/GTO multilayer is a promising transparent conducting electrode material due to its low resistivity, high transmittance, low temperature deposition and low cost components.
Surface and Electrical Properties of 2 wt% Cr-doped Ni Ultrathin Film Electrode for MLCCs
Yim, Haena ; Lee, JinJu ; Choi, Ji-Won ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 224~227
DOI : 10.5369/JSST.2015.24.4.224
In this study, 2 wt% Cr-doped Ni thin films were deposited using DC sputtering on a bare Si substrate using a 4 inch target at room temperature. In order to obtain ultrathin films from Cr-doped Ni thin films with high electrical properties and uniform surface, the micro-structure and electrical properties were investigated as a function of deposition time. For all deposition times, the Cr-doped Ni thin films had low average resistivity and small surface roughness. However, the resistivity of the Cr-doped Ni thin films at various ranges showed large differences for deposition times below 90 s. From the results, 120 s is considered as the appropriate deposition time for Cr-doped Ni thin films to obtain the lowest resistivity, a low surface roughness, and a small difference of resistivity. The Cr-doped Ni thin films are prospective materials for microdevices as ultrathin film electrodes.
Ring-Type Rotary Ultrasonic Motor Using Lead-free Ceramics
Hong, Chang-Hyo ; Han, Hyoung-Su ; Lee, Jae-Shin ; Wang, Ke ; Yao, Fang-Zhou ; Li, Jing-Feng ; Gwon, Jung-Ho ; Quyet, Nguyen Van ; Jung, Jin-Kyung ; Jo, Wook ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 228~231
DOI : 10.5369/JSST.2015.24.4.228
Ultrasonic motors provide high torques and quick responses compared to their magnetic counterparts; therefore, they are widely used in small-scale applications such as mobile phones, microrobots, and auto-focusing modules in digital cameras. To determine the feasibility of lead-free piezoceramics for ultrasonic motor applications, we fabricated a ring-type piezoceramic with a KNN-based lead-free piezoceramic (referred to as CZ5), intended for use in an auto-focusing module of a digital camera. The vibration of the lead-free stator was observed at 45.1 kHz. It is noteworthy that the fully assembled lead-free ultrasonic motor exhibited a revolution speed of 5-7 rpm, even though impedance matching with neighboring components was not considered. This result suggests that the tested KNN-based piezoceramic has great potential for use in ultrasonic motor applications, requiring minimal modifications to existing lead-based systems.
A Passive Visible Light Transponder Using an LED for an Optical Transceiver
Lee, Seong-Ho ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 232~238
DOI : 10.5369/JSST.2015.24.4.232
In this paper, we introduce a passive transponder in which an LED is used for both a light transmitter and a receiver, and a solar cell is used for supplying power to the all devices in the transponder. The LED in the transponder operates as a photodetector in the receiving mode, and acts as a light source in the transmitting mode. The current responsivity of the LED detector was measured to be in the order of
, and the receiving bandwidth with a load resistance of
was about 10 to 30 kHz. Using the LED for an optical transceiver in a VLID transponder, the detection range was about 70 cm when the transponder was illuminated by the visible light from a
LED array in a reader.
Development of Blood Pressure Simulator for Test of the Arm-type Automatic Blood Pressure Monitor
Kim, S.H. ; Yun, S.U. ; Cho, M.H. ; Lee, S.J. ; Lim, M.H. ; Seo, S.Y. ; Jeon, G.R. ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 239~246
DOI : 10.5369/JSST.2015.24.4.239
Blood pressure is possible to diagnose a disease associated with blood pressure and judgment the current health of patients. Automatic blood pressure monitor capable of measuring a blood pressure easily in hospital and at home have become spread. In this study, we developed the blood pressure simulator (BPS) that can test the arm-type automatic blood pressure monitor that is commonly used in hospital. BPS is to produce a pressure similar to the pressure wave generated in the human blood using a servo disk motor. Then, using the silicon tube, it implements the situations such as human blood vessels, and to output the generated pressure waveform. Simply the BPS's phantom put on the cuff and it is able to simulate blood pressure. So anyone can quickly test the blood pressure monitor within one minute and it is possible to shorten the test time required for the automatic blood pressure monitor. In Performance test, the trends and the standard deviation of the values measured in the BPS is similar to the value of the measured pressure from people with normal blood pressure. Thus, the development BPS showed a possibility of taking into account the actual blood pressure measurement environment simulator.
Electroglottographic Spectral Tilt in Frequency Ranges of Vowel Sound
Kim, Ji-Hye ; Jang, Ae-Lan ; Jung, Dong-Keun ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 247~251
DOI : 10.5369/JSST.2015.24.4.247
In this study, electroglottographic spectral tilt (EST) was investigated for characterization of vocal cords vibration. EST was analyzed from the power spectrum of electroglottographic signals by dividing frequency analysis range as full range (0~4 octave), low range (0~2 octave), and high range (2~4 octave). EST of all ranges in female were greater than those in male. In female and male groups, EST of high range was higher than that of low range. This result suggests that EST has at least two components and dividing frequency range in analysis of EST is effective for investigating characteristics of vocal cords vibration.
Design of 8-bit Single Slope ADC for Signal Processing of Multiple Image Sensors
Lee, Jong-Cheol ; Lee, Sang-Hoon ; Kim, Jin-Tae ; Park, Jae-Roul ; Shin, Jang-Kyoo ; Choi, Pyung ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 252~257
DOI : 10.5369/JSST.2015.24.4.252
This paper proposes a single slope A/D converter (SSADC) that is possible to process the signal of the ultraviolet, visible and infrared rays with a single chip. And the proposed SSADC is a type of single channel ADC. In the conventional SSADC, it is possible to process the only one signal with a kind of the sensor because the speed of the operating frequency and the slope of ramp signal generated by the ramp generator are fixed. In order to improve the disadvantages, a ramp generator which has variable slope in ramp function is designed and
MUX(multiplexer) is adopted so that we can change the speed of the operating frequency and the slope of ramp signal. Therefore, the multiple signal processing of the wanted sensors can be possible. The designed circuit is layout by the
CMOS 2-poly 4-metal technology process and is checked through DRC and LVS tools.
A Step-wise Elimination Method Based on Euclidean Distance for Performance Optimization Regarding to Chemical Sensor Array
Lim, Hea-Jin ; Choi, Jang-Sik ; Jeon, Jin-Young ; Byu, Hyung-Gi ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 258~263
DOI : 10.5369/JSST.2015.24.4.258
In order to prevent drink-driving by detecting concentration of alcohol from driver's exhale breath, twenty chemical sensors fabricated. The one of purposes for sensor array which consists of those sensors is to discriminate between target gas(alcohol) and interference gases(
, CO, NOx, Toluene, and Xylene). Wilks's lambda was presented to achieve above purpose and optimal sensors were selected using the method. In this paper, step-wise sensor elimination based on Euclidean distance was investigated for selecting optimal sensors and compared with a result of Wilks's lambda method. The selectivity and sensitivity of sensor array were used for comparing performance of sensor array as a result of two methods. The data acquired from selected sensor were analyzed by pattern analysis methods, principal component analysis and Sammon's mapping to analyze cluster tendency in the low space (2D). The sensor array by stepwise sensor elimination method had a better sensitivity and selectivity compared to a result of Wilks's lambda method.
Fabrication of Silicon Window for Low-price Thermal Imaging System
Sung, Byung Mok ; Jung, Dong Geon ; Bang, Soon Jae ; Baek, Sun Min ; Kong, Seong Ho ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 264~269
DOI : 10.5369/JSST.2015.24.4.264
An infrared (IR) bolometer measures the change of resistance by absorbing incident IR radiation and generates a signal as a function of the radiation intensity. Since a bolometer requires temperature stabilization and light filtering except for the infrared rays, it is essential for the device to be packaged meeting conditions that above mentioned. Minimization of heat loss is needed in order to stabilize temperature of bolometer. Heat loss by conduction or convection requires a medium, so the heat loss will be minimized if the medium is a vacuum. Therefore, vacuum packaging for bolometer is necessary. Another important element in bolometer packaging is germanium (Ge) window, which transmits IR radiation to heat the bolometer. To ensure a complete transmittance of IR light, anti-reflection (AR) coatings are deposited on both sides of the window. Although the transmittance of Ge window is high for IR rays, it is difficult to use frequently in low-price IR bolometer because of its high price. In this paper, we fabricated IR window by utilizing silicon (Si) substrate instead of Ge in order to reduce the cost of bolometer packaging. To enhance the IR transmittance through Si substrate, it is textured using Reactive Ion Etching (RIE). The texturing process of Si substrate is performed along with the change of experimental conditions such as gas ratio, pressure, etching time and RF power.
Short Term Sensor's Drift Analysis and Compensation Using Internal Normalization
Jeon, Jin-Young ; Baek, Jong-Hyun ; Byun, Hyung-Gi ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 270~273
DOI : 10.5369/JSST.2015.24.4.270
One of the main problems when working the chemical sensor is the lack of repeatability and reproducibility of the sensor response. If the problem is not properly taken into consideration, the stability and reliability of the system using chemical sensors would be decreased. In this paper we analyzed the sensor's drift of short term and proposed a compensation method for reducing the effects of the drift in order to improve the stability and the reliability of the chemical sensor. The sensor drift was analyzed by a trend line graph and CV(coefficient of variation) was used to quantify. And we compensated for the drift by using the internal normalization. As a result it was found that the value of CV was decreased after compensation.
Development of Improved Fabrication Methods for 2-axis Electrically Levitated MEMS Gyroscope
Seok, Seyeong ; Lim, Geunbae ;
Journal of Sensor Science and Technology , volume 24, issue 4, 2015, Pages 274~279
DOI : 10.5369/JSST.2015.24.4.274
This paper describes optimizing fabrication methods for 2-axis electrically levitated MEMS gyroscope. Electrostatically levitated gyroscope has very high potential of performance due to the fact that its proof mass is not mechanically bound to any other structures, but its complex structure and difficulty of fabrication holds back the research that only a few researches have been reported. In this work, fabrication method for glass-silicon-glass 3-floor structure for 2-axis electrically levitated MEMS gyroscope is presented, including simplified multi-level glass etch method utilizing photoresist attack, preventing metal diffusion by adding middle layer of metal electrode, overcoming Deep RIE limitation by separate fabrication of silicon structures and keeping the electrode safe from dicing debris.