Semiconductor Gas Sensor를 이용한 유산발효중 휘발성 화합물의 측정

강국희 성균관대학교 생명과학자원연구소 1997 生命資源科學硏究 Vol.4 No.2

The measuring instrument using gas sensor was developed to determine the changes of components in lactic culture during fermentation. The gas sensor was installed in the waterbath to protect from effect of external temperature and the temperature of the waterbath was maintained as 37℃. Volatile flavor components from lactic fermentation moved to semiconductor gas sensor by carrier gas and the sensor responsed as different signal. The different signal of the sensor produced by electric pressure. The changes of the signal showed a similar tendency with those of acidity and the concentration of volatile flavor components during fermentation. The sensitivity of the sensor was highest when the velocity of the carrier gas was 30m1/min. Therefore, the gas sensor can be used to monitor and control the fermentation process.

열처리에 따른 MWCNT/ZnO 복합체 필름 가스센서의NOX 가스 검출 특성

김현수,장경욱 한국전기전자재료학회 2018 전기전자재료학회논문지 Vol.31 No.7

In particular, gas sensors require characteristics such as high speed, sensitivity, and selectivity. In this study,we fabricated a NOX gas sensor by using a multi-walled carbon nanotube (MWCNT)/zinc oxide (ZnO) composite film. The fabricated MWCNT/ZnO gas sensor was then treated by a 450℃ temperature process to increase its detectionsensitivity for NOx gas. We compared the detection characteristics of a ZnO film gas sensor, MWCNT film gas sensor,and the MWCNT/ZnO composited film gas sensor with and without the heat-treatment process. The fabricated gassensors were used to detect NOX gas at different concentrations. The gas sensor absorbed NOX gas molecules, exhibitingincreased sensitivity. The sensitivity of the gas sensor was increased by increasing the gas concentration. Additionally,while changing the temperature inside the chamber for the MWCNT/ZnO composite film gas sensor, we obtained itssensitivity for detecting NOX gas. Compared with ZnO, the MWCNT film gas sensor is excellent for detecting NOX gas. From the experimental results, we confirmed the enhanced gas sensor sensing mechanism. The increased effect byelectronic interaction between the MWCNT and ZnO films contributes to the improved sensor performance.

열처리에 따른 MWCNT/ZnO 복합체 필름 가스센서의 NO_X 가스 검출 특성

김현수,장경욱,Kim, Hyun-Soo,Jang, Kyung-Uk 한국전기전자재료학회 2018 전기전자재료학회논문지 Vol.31 No.7

In particular, gas sensors require characteristics such as high speed, sensitivity, and selectivity. In this study, we fabricated a $NO_X$ gas sensor by using a multi-walled carbon nanotube (MWCNT)/zinc oxide (ZnO) composite film. The fabricated MWCNT/ZnO gas sensor was then treated by a $450^{\circ}C$ temperature process to increase its detection sensitivity for NOx gas. We compared the detection characteristics of a ZnO film gas sensor, MWCNT film gas sensor, and the MWCNT/ZnO composited film gas sensor with and without the heat-treatment process. The fabricated gas sensors were used to detect $NO_X$ gas at different concentrations. The gas sensor absorbed $NO_X$ gas molecules, exhibiting increased sensitivity. The sensitivity of the gas sensor was increased by increasing the gas concentration. Additionally, while changing the temperature inside the chamber for the MWCNT/ZnO composite film gas sensor, we obtained its sensitivity for detecting $NO_X$ gas. Compared with ZnO, the MWCNT film gas sensor is excellent for detecting $NO_X$ gas. From the experimental results, we confirmed the enhanced gas sensor sensing mechanism. The increased effect by electronic interaction between the MWCNT and ZnO films contributes to the improved sensor performance.

이종접합 필름 가스 센서의 유해 가스 검출 및 민감도 특성 분석

김현수 대한설비관리학회 2023 대한설비관리학회지 Vol.28 No.4

In this study, we fabricated a NOx gas sensor using a multi-walled carbon nanotube (MWCNT)/zinc oxide (ZnO) composite film. The fabricated MWCNT/ZnO gas sensor was temperature processes at 450℃ and 710℃, resulting in an enhancement of detection sensitivity for NOx gas, as confirmed through the detection characteristics of NOx gas. Additionally, we compared the detection characteristics of MWCNT film gas sensors and MWCNT/ZnO composite film gas sensors. The fabricated gas sensor was used to detect NOX gas at different concentrations. The gas sensor absorbed NOx gas molecules with an associated increase in the sensitivity. The sensitivity of the gas sensor increased with increasing gas concentration. Furthermore, by varying the temperature inside the chamber for the MWCNT/ZnO composite film gas sensor, we observed high detection characteristics for NOx gas. As a result, the MWCNT/ZnO film gas sensor demonstrated superior performance in detecting NOx gas compared to the MWCNT gas sensor.

역학적 가스센서 연구 동향

장규환(Kuewhan Jang) 호서대학교 공업기술연구소 2021 공업기술연구 논문집 Vol.40 No.2

가스센서는 기체 중에 포함된 특정 가스 성분을 검지하여 그 농도에 따라 전기적 신호로 변환하는 장치이다. 호흡기 질환 바이오센서, 식품 안전 진단 센서, 유독 가스센서 등에 다용하게 활용이 되는 장치로 많은 연구 및 개발이 진행되고 있다. 본 논문에서는 여러 가스센서 중에서 역학 기반의 가스센서 연구 동향을 소개하고자 한다. 역학 기반의 가스센서는 진동 특성을 이용하여 검출 신호를 변환하며 다른 센서 대비 높은 성능을 지니고 있다. 향후 가스센서 시장의 성장과 그 파급력은 클 것으로 예상되는 만큼 역학 기반의 가스센서의 활용 가능성은 매우 높을 것으로 예상된다. A gas sensor is a device that detects a specific gas molecule contained in an air and converts it into an electrical signal according to its concentration. Various research and development are in progress as a device that can be used for many purposes such as a respiratory disease biosensor, a food safety diagnostic sensor, and a toxic gas sensor. In this paper, we are going to introduce the research trend of gas sensor that use mechanical transducer among various gas sensors. A gas sensor based on mechanical transducer converts a detection signal using vibration characteristics and has higher performance compared to other sensors. As the growth of its ripple effect as well as market size, it is expected to be enormous in the future, the possibility of using a mechanical gas sensor is expected to be very large.

Gas sensing characteristics of the FET-type gas sensor having inkjet-printed WS₂ sensing layer

Jeong, Yujeong,Shin, Jongmin,Hong, Yoonki,Wu, Meile,Hong, Seongbin,Kwon, Ki Chang,Choi, Seokhoon,Lee, Taehyung,Jang, Ho Won,Lee, Jong-Ho Elsevier 2019 Solid-State Electronics Vol.153 No.-

<P><B>Abstract</B></P> <P>This paper investigates the gas sensing characteristics of the MOSFET-type sensor having an inkjet-printed WS<SUB>2</SUB> sensing layer. The drain current of the gas sensor increases when NO<SUB>2</SUB> gas is injected into the test chamber since NO<SUB>2</SUB> gas is an oxidizing gas that extracts electrons from the sensing layer. On the contrary, the drain current decreases when H<SUB>2</SUB>S gas is injected into the test chamber since H<SUB>2</SUB>S gas is a reducing gas that donates electrons to the sensing layer. In both cases, the change of the drain current increases as the gas concentration increases. However, for other gases (NH<SUB>3</SUB> and CO<SUB>2</SUB>), the gas sensor has a small change of the drain current. The responses of the gas sensor to 10 ppm NO<SUB>2</SUB>, H<SUB>2</SUB>S, NH<SUB>3</SUB>, and CO<SUB>2</SUB> gases are 15.20%, 7.18%, 1.66%, and 3.02%, respectively. Therefore, the WS<SUB>2</SUB> sensor has a high selectivity for NO<SUB>2</SUB> gas among the four target gases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The drain current of the WS<SUB>2</SUB> gas sensor increases when NO<SUB>2</SUB> gas is injected, but decreases when H<SUB>2</SUB>S gas is injected. </LI> <LI> However, for other gases, the gas sensor has a small change of the drain current. </LI> <LI> As a result, the sensor has a high selectivity for NO<SUB>2</SUB> gas. </LI> </UL> </P>

NO_X 가스 검출 특성을 이용한 MWCNT/ZnO 복합체 필름 가스 센서의 메커니즘 분석

손주형,김현수,박용서,장경욱,Son, Ju-Hyung,Kim, Hyun-Soo,Park, Yong-Seo,Jang, Kyung-Uk 한국전기전자재료학회 2018 전기전자재료학회논문지 Vol.31 No.3

In this study, we fabricated an $NO_X$ gas sensor using a composite film of multi-walled carbon nanotubes (MWCNT)/zinc oxide (ZnO). Carbon nanotubes (CNTs) show good electronic conductivity and chemical-stability, and zinc oxide (ZnO) is a wide band gap semiconductor with a large exciton binding energy. Gas sensors require characteristics such as high speed, sensitivity, and selectivity. The fabricated gas sensor was used to detect $NO_X$ gas at different $NO_X$ concentrations. The sensitivity of the gas sensor increased with increasing gas concentrations. Additionally, while changing the temperature inside the chamber containing the MWCNT/ZnO gas sensor, we obtained the sensitivity and normalized responses for detecting $NO_X$ gas in comparison to ZnO and MWCNT film gas sensors. From the experimental results, we confirmed that the gas sensor sensing mechanism was enhanced in the composite-film gas-sensor and that the electronic interaction between MWCNT and ZnO contributed to the improved sensor performance.

NOX 가스 검출 특성을 이용한 MWCNT/ZnO 복합체 필름 가스 센서의 메커니즘 분석

손주형,김현수,박용서,장경욱 한국전기전자재료학회 2018 전기전자재료학회논문지 Vol.31 No.3

In this study, we fabricated an NOX gas sensor using a composite film of multi-walled carbon nanotubes(MWCNT)/zinc oxide (ZnO). Carbon nanotubes (CNTs) show good electronic conductivity and chemical-stability, and zincoxide (ZnO) is a wide band gap semiconductor with a large exciton binding energy. Gas sensors require characteristicssuch as high speed, sensitivity, and selectivity. The fabricated gas sensor was used to detect NOX gas at different NOXconcentrations. The sensitivity of the gas sensor increased with increasing gas concentrations. Additionally, while changingthe temperature inside the chamber containing the MWCNT/ZnO gas sensor, we obtained the sensitivity and normalizedresponses for detecting NOX gas in comparison to ZnO and MWCNT film gas sensors. From the experimental results, weconfirmed that the gas sensor sensing mechanism was enhanced in the composite-film gas-sensor and that the electronicinteraction between MWCNT and ZnO contributed to the improved sensor performance.

Mechanistic Analysis of MWCNT/ZnO Composite Film Gas Sensor Based on NOx Gas Detection Characteristics

김현수 대한설비관리학회 2023 대한설비관리학회지 Vol.28 No.4

A NOx gas sensor was fabricated using a multi-walled carbon nanotube (MWCNT)/zinc oxide composite film. Gas sensors require characteristics such as high speed, sensitivity, and selectivity. Thus, carbon nanotubes (CNTs) having good electronic properties, chemical stability, and great conductivity and zinc oxide, a wide band-gap semiconductor with a large exciton binding energy, were selected in this study. The fabricated gas sensor was used to detect NOx gas at different concentrations. The gas sensor absorbed NOx gas molecules with an associated increase in the sensitivity. The sensitivity of the gas sensor increased with increasing gas concentration. By varying the temperature inside the chamber of the MWCNT/ZnO composite film gas sensor, the sensitivity and normalized response for detecting NOx gas was determined. Based on comparative analysis with ZnO, the MWCNT film gas sensor is excellent for detecting NOx gas. The experimental data confirmed the enhanced gas sensing properties and sensor performance derived from the electronic interaction between the MWCNTs and ZnO film.

MWCNT/ZnO 복합체 필름을 이용한 가스센서의 NO_x가스 검출 특성 분석

김현수,이원재,박용서,장경욱,Kim, Hyun-Soo,Lee, Won-Jae,Park, Yong-Seo,Jang, Kyung-Uk 한국전기전자재료학회 2016 전기전자재료학회논문지 Vol.29 No.5

In this study, we fabricated $NO_x$ gas sensor by using multi-walled carbon nanotubes(MWCNT)/zinc oxide(ZnO) composite film. Carbon nanotubes (CNTs) have good electronic, chemical-stability, and sensitivity characteristics. And zinc oxide (ZnO) is a wide band gap and large exciton binding energy semiconductor. In particular, gas sensors require characteristics such as high speed, sensitivity, and selectivity. The fabricated gas sensor was used to detect $NO_x$ gas for different values of the $NO_x$ gas concentrations. The gas sensor that absorbed$NO_x$ gas molecules showed a increasing in resistance. The sensitivity of the gas sensor was increased by increasing the gas concentrations. Additionally, while changing the temperature inside the chamber for the MWCNT/ZnO composite film gas sensor, we obtained the sensitivity. And the comparison analysis to ZnO film gas sensor for detecting $NO_x$ gas. From the experiment result, we confirmed improvement of $NO_x$ gas detection characteristics using the MWCNT/ZnO composite film.