• Journal of Korean Electronics
• /
• v.3 no.3-4
• /
• pp.76-79
• /
• 1983

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.08a
• /
• pp.247-247
• /
• 2010

전계효과 트랜지스터를 이용한 바이오센서는 하나의 칩 위에 많은 센서 소자를 집적할 수 있으므로, 같은 종류의 센서를 다수 배열함으로써 다차원화할 수 있고, 다른 종류의 센서를 여러개 배열함으로써 다기능화할 수 있다. 또한 지능회로와 함께 집적하여 지능화하거나, 관련회로 및 장치들을 함께 집적함으로써 시스템화할 수 있기 때문에 최첨단 센서로 각광을 받고 있다. 그러나, 전계효과 트랜지스터를 이용한 바이오센서는 게이트 영역에 생체 분자를 고정시키는 것이 어렵고, 고정되더라도 생체 분자의 양이 미량이어서 재현성이 떨어지며, 생체 분자가 발생시키는 시그널이 적어 전류 세기 변화에 대한 검출감도가 저하되는 문제점이 있다. 본 연구에서는 반도체 리소그래피 공정을 이용하여 생체 분자를 물리 화학적 처리 없이 게이트 영역에 집중적으로 고정시킬 수 있는 기술에 대해 연구하였다. 산화막이 증착된 기판 위에 포토레지스트를 도포한 뒤 리소그래피공정을 이용하여 패터닝 하였으며 기판 위에 human embryonic kidney(HEK)-293 세포를 배양하였다. 연구결과, 친수성인 포토레지스트보다 소수성인 산화막 영역에 다수의 세포가 선택적으로 집중 배양됨을 확인하였다. 따라서 본 연구결과를 바이오센서에 적용할 경우 센서의 검출감도를 향상시킬 수 있을 것으로 기대된다.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.1898-1899
• /
• 2005

반도체 집적회로 공정에서 사용되는 폴리이미드 포토레지스트(P12723, Dupont)를 감습막으로 사용하는 마이크로 습도센서 소자를 제작하였다. 마이크로 습도센서는 실리콘 웨이퍼 기판 위에 $SiO_2$ 박막을 건식열산화 공정으로 제작하고, Al 박막을 포토리소그라피 공정으로 패터닝 한 IDT (Interdigital Transducer)를 전극 위에 폴리이미드 포토레지스트를 공정변수를 다양하게 조절하면서 감습막으로 제작하였다. 폴리이미드 감습막은 스핀코팅법으로 제작하였으며, 회전수를 조절하여 두께를 변화시켰다. 완성된 마이크로 습도센서 소자의 상대습도 변화$(10{\sim}90% RH)$에 따른 정전용량 값 변화를 항온항습조 내에서 다양한 온도에서 HP4192A Impedance Analyzer를 사용하여 조사함으로써, 폴리이미드 포토레지스트를 사용하는 마이크로 정전용량형 습도센서의 제작 가능성을 검토하였다. 폴리이미드 정전용량형 마이크로 습도센서는 다양한 인가 전원 주파수에서 기준 센서로 사용된 상용 Vaisala Hygrometer와 유사한 감습특성 및 응답특성을 보였다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.4
• /
• pp.553-559
• /
• 2020

Seaweed(Laver), Korea's largest export product, is currently focused on mass production due to the market situation in Korea. This naturally led to a decrease in the quality of seaweed. Therefore, in this paper, the present method was produced and tested by changing the way of adjusting the ratio of seaweed mixing, which was dependent on the user's sense and experience in the production of seaweed. In addition, I developed an embedded measurement system that can determine the concentration of a mixture of gold in real time based on primary image information obtained through an IR LED lamp that generates a light source and a photo sensor that detects concentration. By collecting and storing precise data in real time, it is easier to cope with the previous year's data in a work environment that is repeated every winter.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.10 no.3
• /
• pp.237-242
• /
• 2016

The major advantage of slip-ring technology in Spiral CT is that it facilitates continuous rotation of the x-ray tube, so that volume data can be acquired from a patient quickly. Not only for such a fast scan, but also for the dose reduction purpose, high signal-to-noise ratio and fast data acquisition system is required. In this study, we have built a multi-channel photodetector and multi-channel data acquisition system for CT application. The detector module consisted of CdWO4 crystal and Si photodiode in 16 channels. For the performance test of the preamplifier stage, both the transimpedance and switched integrator types are optimized for the photodetector modules. Switched integrator showed better noise performance in the limited bandwidth which is suitable for the current CT application. The control sequence for data acquisition and 20 bit ADC is designed with VHDL(Very High Speed Integrated Circuit Hardware Description Language) and implemented on FPGA(Field Programmable Gate Array) chip. Our Si photodiode detector module coupled to CdWO4 crystal showed comparable signal with other commercially available photodiode for CT. Switched integrator type showed higher SNR but narrower bandwidth compared to transimpedance preamplifier. Digital hardware is designed by FPGA, so that the control signal could be redesigned without hardware alteration.

• Korean Journal of Optics and Photonics
• /
• v.29 no.6
• /
• pp.268-274
• /
• 2018

In this study we suggest a humidity-sensitive color sensor using a one-dimensional photonic crystal and Hong Kong University of Science and Technology-1 (HKUST-1), which is a metal-organic framework (MOF) substance. One-dimensional photonic crystals have a photonic band gap, due to a periodic refractive-index change, and block and reflect light components in a specific wavelength band. The refractive index of HKUST-1 differs in dry and humid environments. Herein we designed a sensor using the presence of the photonic band gap, with FDTD simulation. As a result of optical analysis, the color conversion of the reflected light was superior to the color conversion of the transmitted light. When the center wavelength of the photonic band gap was 550 nm, the maximum peak value of the wet environment increased by a factor of about 9.5 compared to the dry environment, and the color conversion from achromatic to green was excellent as a sensor. The results of this study suggest the application of MOF materials to moisture sensors, and the nanostructure design of MOF materials will expand the applications to industrial devices.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.517-520
• /
• 2003

The snow-fatting measurement system including the snow sensor applying the photo-coupler is investigated in this study and using this snow sensor the height of snow fallen is measured. To measure the snow depth, five photo sensors are arranged with 5 mm distance. The snow-falling measurement system, which is measuring the motor revolution controlled with stepping motor, is mounted above the snow surface. From this work, it is feasible to measure quantitatively the snow on real time. Its software implements a proven method to achieve valid measurements also under difficult conditions as future study. In cases where the snow sensor is applieded to the prediction of snow in the meteorological observation system and the snow removing system, it is recommend the GRS-Option in order to improve the quality of snow measurements for better compensation.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1999.12a
• /
• pp.321-326
• /
• 1999

• Journal of Korea Society of Industrial Information Systems
• /
• v.26 no.6
• /
• pp.11-16
• /
• 2021

In this paper, a quality inspection system was developed to identify the defective assembly of connectors used in automobile wiring. For waterproof connectors, an internal seal must be inserted for waterproofing. However, there are cases where it is omitted or double-inserted during production. An automatic inspection jig was designed using photosensors and touch switches to classify good and bad connector components. In the case of the existing visual inspection, 6,400 connectors were inspected when 5 people inspected for 8 hours. However, when using the inspection jig developed under the same conditions, 20,000 pieces were inspected. In other words, the productivity is greatly improved compared to the conventional visual inspection.

• Journal of IKEEE
• /
• v.22 no.4
• /
• pp.922-932
• /
• 2018

Radial distance sensors are widely used for surveying and autonomous navigation. It is necessary to train the operation principle of these sensors and how to apply them. Although commercialization of radial distance sensor continues to be cost-effective through lower performance, but it is still expensive for educational purposes. In this paper, we propose a distance sensor module with object tracking using radial array of low cost phototransistor which can be used for educational robot. The proposed method is able to detect the position of a fast moving object immediately by arranging the phototransistor in the range of 180 degrees and improve the sensing angle range and track the object by the sensor rotation using the servo motor. The scan speed of the proposed sensor is 50~200 times faster than the commercial distance sensor, thus it can be applied to a high performance educational mobile robot with 1ms control loop.