• Journal of Magnetics
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• v.12 no.1
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• pp.35-39
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• 2007

A highly sensitive magnetic sensor using the Giant MagnetoImpedance effect has been developed. The sensor performance is studied and estimated. The sensor circuitry consists of a square wave generator (driving source), a sensing element in a form of composite wire of a 25 $\mu$m copper core electrodeposited with a thin layer of soft magnetic material ($Ni_{80}Fe_{20}$), and two amplifier stages for improving the gain, switching mechanism, scaler circuit, an AC power source driving the permeability of the magnetic coating layer of the sensing element into a dynamic state, and a signal pickup LC circuit formed by a pickup coil and an capacitor. Experimental studies on sensor have been carried out to investigate the key parameters in relation to the sensor sensitivity and resolution. The results showed that for high sensitivity and resolution, the frequency and magnitude of the ac driving current through the sensing element each has an optimum value, the resonance frequency of the signal pickup LC circuit should be equal to or twice as the driving frequency on the sensing element, and the anisotropy of the magnetic coating layer of the sensing wire element should be longitudinal.

• Journal of Fashion Business
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• v.25 no.5
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• pp.99-113
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• 2021

This study aimed to produce sensors for measuring thigh motor skills. A textile stretch sensor was manufactured using a CNT(Carbon Nano Tube) 0.1 wt% water SWCNT(Single-Walled Carbon Nano Tube) solution, and different designs were applied to increase the sensitivity of the sensor, and different GF(Gauge Factor) values were compared using UTM devices. The same design was applied to fabrics and weaves to observe changes in performance according to fibrous tissue, and the suitability of sensors was determined based on tensile strength, elongation, and the elongation recovery rate. Sensitivity was found to vary depending upon the design. Thus the manufactured sensor was attached to a pair of fitness pants as a prototype, divided into lunge position and squat position testing, and the stretch sensor was used to measure thigh movements. It was shown that stretch sensors used to measure thigh motor skills should have light and flexible features and that elongation recovery rates and tensile strength should be considered together. The manufactured stretch sensor may be applicable to various sports fields that use lower limb muscles, wearable healthcare products, and medical products for measuring athletic ability.

• Journal of Sensor Science and Technology
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• v.30 no.6
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• pp.456-460
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• 2021

In this study, a Non-Dispersive Infrared (NDIR) Carbon Dioxide (CO₂) sensor with an externally exposed optical cavity is proposed for improving sensitivity. NDIR CO₂ sensors with high performance must use a lamp-type infrared (IR) source with a strong IR intensity. However, a lamp-type IR source generates high thermal energy that induces thermal noise, interfering with the accuracy of the CO₂ concentration measure. To solve this problem, the optical cavity of the NDIR CO₂ sensor is exposed to quickly dissipate heat. As a result, the proposed NDIR CO₂ sensor has a shorter warm-up time and a higher sensitivity compared to the conventional NDIR CO₂ sensor.

• Journal of Sensor Science and Technology
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• v.33 no.1
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• pp.7-11
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• 2024

Soft-pressure sensors have numerous applications in soft robotics, biomedical devices, and wearable smart devices. Herein, we present a highly sensitive electronic skin device with an isotropic wrinkled pressure sensor. A conductive ink for soft pressure sensors is produced by a solution process using polydimethylsiloxane (PDMS), poly 3-hexylthiophene (P3HT), carbon black, and chloroform as the solvents. P3HT provides high reproducibility and conductivity by improving the ink dispersibility. The conductivity of the ink is optimized by adjusting the composition of the carbon black and PDMS. Soft lithography is used to fabricate a conductive elastic structure with an isotropic wrinkled structure. Two conductive elastic structures with an isotropic wrinkle structure is stacked to develop a pressure sensor, and it is confirmed that the isotropic wrinkle structure is more sensitive to pressure than when two elastic structures with an anisotropic wrinkle structure are overlapped. Specifically, the pressure sensor fabricated with an isotropic wrinkled structure can detect extremely low pressures (1.25 Pa). Additionally, the sensor has a high sensitivity of 15.547 kpa^-1 from 1.25 to 2500 Pa and a linear sensitivity of 5.15 kPa^-1 from 2500 Pa to 25 kPa.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.1
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• pp.109-114
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• 2024

The bio-sensing properties of TE and TM guided modes in the coupled plasmon-waveguide resonance (PWR) configuration are investigated. The modal transmission-line theory (MTLT) is used for numerical analysis. The proposed PWR bio-sensor is composed of multi-layered configuration with N pairs of MgF2-Si3N4 layers to enhance the sensitivity of a conventional Ag-based surface plasmon resonance bio-sensor. The angular sensitivity of bio-sensor is numerically analyzed for a wide range of biological solutions (refractive index 1.33~1.37). Furthermore, the availability of sensor to detect cancer cells and blood plasma concentration is evaluated. Finally, the results indicate that the proposed bio-sensor is capable efficiently to detect various kinds of cancer cells and different glucose concentrations in urine.

• Journal of Sensor Science and Technology
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• v.17 no.4
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• pp.303-307
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• 2008

$NiO,\;Cu_2O,\;Mn_2O_3$ and $Cr_2O_3$ as p-type semiconductors were added in CoO with 15 wt.% ethylene glycol binder and measured the butane gas sensing characteristics. The highest sensitivity is obtained for the NiO-CoO sensors. CoO-20 at.% NiO sensor with 15 wt.% ethylene glycol binder sintered at $1100^{\circ}C$ for 24 h exhibits high sensitivity of 90 % to 5000 ppm butane gas at the sensor temperature of $250^{\circ}C$, compared to low sensitivities at the low operating temperature for commercial sensors. Response and recovery times are, respectively, within few seconds and 1min in the static flow system, indicating rapid adsorption and desorption of butane gas on sensor surface even at this low temperature.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.10-13
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• 2006

This paper describes on the fabrication and characteristics of a 3C-SiC (Silicon Carbide) micro pressure sensor for harsh environment applications. The implemented micro pressure sensor used 3C-SiC thin-films heteroepitaxially grown on SOI (Si-on-insulator) structures. This sensor takes advantages of the good mechanical properties of Si as diaphragms fabricated by D-RIE technology and temperature properties of 3C-SiC piezoresistors. The fabricated pressure sensors were tasted at temperature up to $250^{\circ}C$ and indicated a sensitivity of 0.46 mV/V*bar at room temperature and 0.28 mV/V*bar at $250^{\circ}C$. The fabricated 3C-Sic/SOI pressure sensor presents a high-sensitivity and excel lent temperature stability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.337-340
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• 2004

To develop the highly sensitive Magneto-Impedance sensor, the amorphous ribbon was micro-processed to meander type sensor pattern and the filter circuit was constructed with this pattern. Its external magnetic field dependence of impedance and the output properties of the filter circuit were investigated. The impedance of the pattern had a peak value at the magnetic field of 10 Oe and its changing ratio was about 280%. The impedance change per unit magnetic field was about 36%, in which the output with high sensitivity and linearity could be obtained. The output sensitivity was about 7%/Oe at bias field of 6 Oe..

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.73-76
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• 2002

In this paper we present an integrated Hail sensor It for fan motors, fabricated in industrial bipolar process. As a discrete Hall sensor and signal processing circuitry In the fan motor system were Integrated into single chip a temperature dependence of Hall sensitivity and Hall offset voltage can be compensated and cancelled by on-chip circuitry. We Propose a novel temperature compensation of Hall sensitivity with negative temperature coefficient (TC) using the differential amplifier gain with Positive TC. After a package of the chip was sealed using a plastic Package 20 Pins, the thermal and magnetic characteristics were investigated. The obtained experimental results are in agreement with analytical predictions and have more excellent performance than\ulcorner conventional the fan motor system using discrete Hall sensor.

• Journal of Sensor Science and Technology
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• v.25 no.3
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• pp.173-177
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• 2016

Tape casting ceramics technology has been adopted for the fabrication of solid state electrochemical $CO_2$ sensors and the packaging substrates. The fabricated $CO_2$ sensors exhibit a fast response and a good recovery with the almost theoretical sensitivity of 37 mV/decade, corresponding to a sensor operating temperature of 373 K. The two packaging methods, the wire bonding package and the surface- mounted on the ceramic package, were compared with respect to their power consumption and mass production feasibility. In terms of the ease of fabrication, the surface mount packaging technology is superior to the wire bonding technology but its power consumption is approximately twice that of the wired package.