CNT 필름 전기화학 센서의 온도 의존 특성에 관한 연구

노재하,안형수,안상수,이창한,이상태,이문진,서동민,장지호 한국센서학회 2022 센서학회지 Vol.31 No.3

In this study, we investigated a carbon nanotube (CNT) film sensor to detect hazardous and noxious substances distributed in seawater. The response change of the sensor was studied according to environmental temperature, and its temperature coefficient of resistance (TCR, α) was measured. The temperature of the CNT film (~50 µm) was in the range of 20–50oC, and αCNT was calculated to be −0.0011 %/oC. We experimentally confirmed that the CNT film had a smaller TCR value than that of the conventional sensor. Therefore, we investigated the response change of the CNT sensor according to temperature. The CNT sensor showed a relatively small error of approximately 2.3 % up to 30oC, which is within the temperature range of the seawater of the Korean Peninsula. However, when the temperature exceeded 40oC, the error in the CNT sensor increased by more than 5.2 %. We fabricated a metal oxide (ITO, indium-tin-oxide) film and compared its performance with that of the CNT sensor. The ITO sensor showed an error of >12.5 % at 30oC, indicating that in terms of the stability of the sensor to temperature, the CNT film sensor has superior performance.

새우양식 환경 모니터링을 위한 센서기술 동향 분석

허신 ( Shin Hur ),박중호 ( Jung Ho Park ),최상규 ( Sang Kyu Choi ),이창원 ( Chang Won Lee ),김주완 ( Ju Wan Kim ) 한국센서학회 2021 센서학회지 Vol.30 No.3

RAS(Recirculating aquaculture system) 방식 또는 바이오플락기술를 사용한 흰다리 새우의 육상 양식을 통해서 새우 개체의 생존율과 고밀도 생산율을 향상시키기 위한 양식의 원리 및 장치 구성, 국내외 수질 모니터링 센서, 현재의 양식 모니터링 시스템의 문제점 파악 및 미래의 양식 모니터링을 위한 대책을 분석 하였다. 흰다리 새우 양식을 위해서는 수조별 온도, pH, DO, 염도 측정이 기본적으로 필요하며, 암모니아성 질소, 질산성 질소, 아질산성 질소, 생장 관리를 위한 이온성 물질의 측정이 필요하다. 특히 센서재질에 있어서는 SUS304도 부식이 되는 고염도 환경에서 견딜수 있어야 하며, 고탁도 및 부유물질에 의한 생물 부착에 견딜 수 있는 센서가 사용되어야 한다. 또한 내구성 및 측정값 신뢰도, 가격 경쟁력 있는 센서 및 시스템 공급이 필요하다. 바이오플락 양식 환경에서는 고염분, 고부유물 환경에서 견딜 수 있는 센서의 내구성과 데이터 안정성, 신뢰도가 무엇보다 중요하다. 향후 흰다리 새우 및 수산 양식을 위한 최적 양식환경을 확보하기 위해서는 양식 생육 환경 현장의 수질을 측정하고 적정환경을 결정하며, 자동제어 시스템을 이용하여 제어하고 축적된 데이터를 활용 및 분석하여 지능적으로 관리하는 기술을 개발하는 것이 필요하다. In this study, the IoT sensor technology required for improving the survival rate and high-density productivity of individual shrimp in smart shrimp farming (which involves the usage of recirculating aquaculture systems and biofloc technology) was analyzed. The principles and performances of domestic and overseas water quality monitoring IoT sensors were compared. Furthermore, the drawbacks of existing aquaculture monitoring technologies and the countermeasures for future aquaculture monitoring technologies were examined. In particular, for farming white-legged shrimp, an IoT sensor was employed to collect measurement indicators for managing the water quality environment in real-time, and the IoT sensor-based real-time monitoring technology was then analyzed for implementing the optimal farming environment. The results obtained from this study can potentially contribute to the realization of an autonomous farming platform that can improve the survival rate and productivity of shrimp, achieve feed reduction, improve the water quality environment, and save energy.

맥 센서 어레이(array)의 실리콘(silicone) 코팅 두께에 따른 센서 간 간섭효과

전민호 ( Min Ho Jun ),전영주 ( Young Ju Jeon ),김영민 ( Young Min Kim ) 한국센서학회 2016 센서학회지 Vol.25 No.1

Pulse diagnosis is one of the representative diagnostic methods in Oriental medicine. In this study, a pulse pressure sensor array coated with silicone, which includes 6 piezo-resistive sensors and 1 thermistor, is fabricated for pulse measurement. It is necessary to coat the pulse sensor array with silicone to avoid the fracture or damage of pressure sensors when the sensor is in contact with the skin and a constant pressure is applied. However, the silicone coating on the pulse sensor array can cause signal interference among the sensors in the pulse sensor array. The interference number (IN), a calculation for expressing the degree of interference among channels, is changed according to the silicone thickness on the pulse sensor array. The IN is increased by a thick silicone coating, but the fabrication error, an important index for the mass production of the sensor array, is reduced by the thickness of the silicone coating. We propose that the thickness of the silicone on the pulse sensor array is an important consideration for the performance of the fabricated sensor and manufacturing repeatability.

손가락 힘측정장치의 3축 힘센서 설계

이경준 ( Kyeong Jun Lee ),김갑순 ( Gab Soon Kim ) 한국센서학회 2016 센서학회지 Vol.25 No.2

This paper describes the design and fabrication of a three-axis force sensor with three parallel plate structures(PPSs) for measuring force in a finger force measuring system for a spherical object catch. The three-axis force sensor is composed of a Fx force sensor, Fy force sensor and a Fz force sensor, and the elements of Fx force sensor and Fy force sensor are a parallel plate structure(PPS) respectively and Fz force sensor is two PPS. The three-axis force sensor was designed using FEM(Finite Element Method), and manufactured using strain-gages. The characteristics test of the three-axis force sensor was carried out. As a test results, the interference error of the three-axis force sensor was less than 1.32%, the repeatability error of each sensor was less than 0.04%, and the non-linearity was less than 0.04%.

차량용 통합 센서 모듈 제어를 위한 시뮬레이터 개발

전진영,박정연,변형기 한국센서학회 2013 센서학회지 Vol.22 No.1

The integrated sensor module of vehicle combines the functions of rain sensor, auto defog sensor, and sun angle sensor into a single module. These functions originally were applied to work separatively. This integrated sensor module should meet the each performance which appears from the individual modules up to the same level or higher. Therefore, it is important to verify the stability and the accuracy considering the characteristics of the integrated sensor module according to various situations. For the verification, we need to use the actual data of integrated sensor module measured but, a lot of time and money is needed to collect data measured under various circumstances when operating. Thus, through the development of this simulator for the control of the integrated sensor module, we can use it effectively for the initial verification of integrated sensor module by implementing the various situations. In this paper, the simulator for controlling the integrated sensor module which combines vision-based rain sensor, auto defog sensor, auto light sensor, and sun angle sensor has been developed.

보상용 적외선 센서를 사용한 비분산 적외선 이산화탄소 센서의 온도특성

이승환 ( Seung Hwan Yi ) 한국센서학회 2016 센서학회지 Vol.25 No.2

NDIR CO2 gas sensor was built with ASIC implemented thermopile sensor which included temperature sensor and unique elliptical waveguide structures in this paper. The temperature dependency of dual infrared sensor module (CO2 and reference IR sensors) has been characterized and its output voltage characteristics according to the temperature and gas concentration were proposed for the first time. NDIR CO2 gas and reference IR sensors showed linear output voltages according to the variation of ambient temperatures from 243 K to 333 K and their slopes were 14.2 mV/K and 8.8 mV/K, respectively. The output voltages of temperature sensor also presented a linear dependency according to the ambient temperature and could be described with . V(T) = -3.191+0.0148T(V) The output voltage ratio between CO2 and reference IR sensors revealed irrelevant to the changes of ambient temperatures and gave a constant value around 1.6255 with standard deviation 0.008 at 0 ppm. The output voltage of CO2 gas sensor at zero ppm CO2 gas consisted of two components; one is caused by the HPB (half pass-band) of IR filter and the other is attributed to the part of CO2 absorption wavelength. The characteristics of output voltages of CO2 gas sensor could be accurately modeled with three parameters which are dependent upon the ambient temperatures and represented small average error less than 1.5% with 5% standard deviation.

입사광량의 조절과 이에 따른 비분산 적외선 알코올 센서의 온도 특성과 보정

김진호 ( Jinho Kim ),조희찬 ( Heechan Cho ),이승환 ( Seunghwan Yi ) 한국센서학회 2018 센서학회지 Vol.27 No.1

In this paper, we describe the thermal characteristics of the output voltages of ethanol gas sensor according to the amount of radiation incident on the infrared sensors located at each focal point of two elliptical waveguides. In order to verify the output characteristics of the gas sensor according to the amount of incident light on the infrared sensor, two combinations of sensor modules were fabricated. Hydrophobic thin film is deposited on one of the reflectors of sensor modules and one of the two infrared sensors was equipped with a hollow disk (1.0 Ø), and the temperature characteristics of the infrared sensor equipped with the hollow disk (1.0 Ø) and the infrared sensor without the disk were tested. The temperature was varied from 253 K to 333 K at 10 K intervals based on 298 K. The properties of ethanol gas sensor have been identified with respect to varying temperature for a range of ethanol concentration from 0 ppm to 500 ppm. In the case of an infrared sensor equipped with a hollow disk (1.0 Ø), the output voltage of the sensor decreased by 0.8 mV and 1 mV, respectively, as the temperature increased. Conversely, the output voltage of the diskless infrared sensor showed an average increase of 67 mV and 57 mV as the temperature increased. The ethanol concentrations estimated on the basis of results show an error of more than 10 % for less than 100 ppm concentration. However, if the ethanol concentration exceeds 100 ppm, the gas concentration can be estimated within the range of ±10%.

살모넬라와 면역글로블린(hIgG)의 항원-항체반응 감지를 위한 표면 플라즈몬 공명형 센서시스템의 특성

엄년식,고광락,함성호,김재호,이승하,강신원,Um, N.S.,Koh, K.N.,Hahm, S.H.,Kim, J.H.,Lee, S.H.,Kang, S.W. 한국센서학회 1998 센서학회지 Vol.7 No.4

본 연구에서는 특정한 생물학적 의미를 갖는 물질들간의 결합 및 분리과정을 실시간에 측정하기 위해 빠른 응답특성과 높은 감도를 갖는 표면 플라즈몬 공명 (Surface Plasmon Resonance, SPR) 현상을 이용한 센서 시스템을 제작하였다. SPR 시스템의 프리즘 표면에 일정 두께의 금 박막이 진공증착된 센서칩을 두고 이 아래에 위치한 시료충전셀에 살모넬라 (salmonella) 항체를 주입시켜 항체가 센서칩 표면에서 자기집합 (self-assembly) 함에 따라 공명각이 변화하는 현상을 측정하였다. 이후 분석대상물질인 살모넬라 항원을 주입하여 항체와의 결합 상태를 일정 시간 간격을 두고 공명각의 변화로서 측정하고 이 결과를 분석하였다. 또한 human Immunglobulin G (hIgG)를 항원으로 한 항원-항체 반응 역시 살모넬라의 경우와 같은 방법으로 측정하였다. 그 결과 살모넬라의 항체는 센서칩 표면에서 약 10분 동안 자기집합하고 반응이 포화됨을 공명각의 변화를 통해 볼 수 있었으며, hIgG의 항체의 경우는 약 60분 동안 반응을 하고 포화됨을, 그리고 살모넬라와 hIgG의 항원 (분석대상물질) 은 모두 각각의 항체에 대해서 약 1분 이내에 결합하고 포화됨을 볼 수 있었다. Surface Plasmon Resonance (SPR) sensor system, has rapid response and high sensitivity, can be applicable for detecting reaction times of many biospecific interactions. A SPR sensor system was constructed to detect the antigen-antibody reactions of salmonella and hIgG (human immunoglobulin G). Sensor chips made of gold thin film were used for detecting biological bindings of antigen and antibody reactions. The antigen and antibody reactions for salmonella and hIgG were carried out with various time intervals to observed characteristics of these reactions using SPR sensor system. The resonance angle shift changes were clearly observed at the time of salmonella or hIgG antibody injection into sample cell since each antibody was self-assembled on gold chip surface of the sensor. It was found that the antibodies of salmonella and hIgG reacted with its sensor chip surface in 10 minutes and 60 minutes respectively. And the antigens of both salmonella and hIgG were bound to its antibody within 1 minute.

정온도형 유속 및 유량 측정센서

박세광,김형표,Park, Se-Kwang,Kim, Hyoung-Pyo 한국센서학회 1992 센서학회지 Vol.29 No.3

기체와 액체의 유숙을 측정하기 위한 반도체 기술을 이용한 소형의 정온도형 유속센서가 제작되었다. 유속센서는 유속에 영향을 받는 대류 열전달만을 검출하도록 설계되었고, 다른 종류의 열전달과 간섭효과는 기준센서의 사용으로 상쇄되도록 하였다. 원리는 유동에 의한 센서 양단전류의 변화로 유속을 측정하는 것이다. 이 유속센서의 실험은 수돗물로 가는 관(지름 8mm)을 사용하여 수행되었다. 그 결과 센서의 소비전력과 유속의 제곱근 사이의 관계는 유속이 0-200cm/sec 범위에서 거의 선형으로 나타났다. A constant temperature type of flow sensor using a solid state micromachining technology was developed for measuring the velocity of gas or liquid. It was designed to detect only the heat convection related to flow velocity. Other heat transfer terms and common mode interferences are canceled by differentiating both reference and exposed flow sensor. It employs the principle that the change of current through the sensing element can be used to measure the flow velocity. An experimental study of the behavior on this flow sensor was performed in a narrow tube(diameter : 8mm) for city water. The relation between power consumption of the flow sensor and square-root of flow velocity is almost linear in the low velocity range(0-200 cm/sec).

Fe_2O_3 후막을 이용한 alcohol sensor 제작 및 감응특성

이윤수,송갑득,이상문,심창현,최낙진,주병수,이덕동,허증수 한국센서학회 2002 센서학회지 Vol.11 No.2

저비용과 휴대성을 고려한 알코올 경보기의 제작을 위해 동작온도가 낮고 감도가 높은 반도체 가스 센서를 제작하였다. Fe_2O_3에 금속 산화물인 MoO_3, V_2O_5, TiO_2, 그리고 CdO 등을 첨가하여 스크린 프린팅법을 이용하여 센서를 제작하였다. 센서의 전기적 안정성을 위하여 질소 분위기에서 700 ℃, 2시간 동안 열처리를 하였다. 알코올, 탄화수소계 가스와 담배연기 등을 사용하여 센서의 가스 감도를 조사하였다. V_2O_5를 첨가한 센서가 알코올 가스 1,000 ppm에 대해서 약 80 ~ 90%의 감도를 보이며, 타 가스에 대한 선택성도 가짐을 알 수 있었다. 제작된 센서와 PIC-chip을 사용하여 휴대 가능한 경보기를 제작할 수 있었다. In order to get low cost and portability, semiconductor gas sensor need to have low operating temperature and high sensitivity. Fe_2O_3 based sensors which were doped with metal oxidecatalysts(MoO_3, V_2O_5, TiO_2, and CdO) were fabricated by screen printing method. To improve electrical stability of sensors, the Fe_2O_3 sensors were annealed in N_2 at 700 ℃ for 2 hours. The V_2O_5 doped Fe_2O_3 sensor showed about 80 ~ 90 % sensitivity at alcohol 1,000 ppm and have good selectivity to hydrocarbon gas and tobacco odors. The fabricated sensor and PIC-chip were employed for portable alarm system.