• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1767-1772
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• 2008

A microcantilever is a well-known MEMS structure for sensing bio-chemical molecules. When bio-chemical molecules are adsorbed on the microcantilever's surface, resonance frequency shift is generated. There are two issues in this phenomena. The first one is which one between mass change and surface stress change effects is more dominant on the resonance frequency shift. The second one is what will be the performance change when the boundary condition is changed from cantilevers to double clamped beams. We have studied the effect of surface stress change and compared it with that of mass change by using FEM analysis. Furthermore, for microstructures having different boundary conditions, we have studied Q-factor, which determines the detection limit of micro/nano mechanical sensors.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.309-312
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• 2002

Precision stage is essential device for semiconductor equipments, fiber optic assembly systems and micro machines. In this paper, we develop a piezo-electric inchworm type actuator for long stroke ultra precision linear stages, and implement a controller to interface with commercial motion controllers. It provides fast implementation of precise position control system substituting for rotary motor. In the future, using a laser interferometer as a position sensor, we plan to implement a nano meter precision stage.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.169-171
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• 2006

센서네트워크의 전력소모를 최소화, 최적화하기 위해서는 센서노드들을 실제 환경에 설치하기 이전에 시뮬레이터를 이용하여 센서네트워크의 전력상황을 정확히 추정해야 한다. 이러한 시뮬레이터를 위해서는 센서노드의 소모에너지를 정확히 분석할 수 있는 전력모델이 반드시 요구된다. 본 논문은 센서노드의 소비전력을 정확하게 측정할 수 있는 환경과 방법을 제시하며, 이 환경과 방법을 이용하여 센서노드의 소모전력을 명령어기반과 동작상태기반으로 정확히 측정 분석하고, 센서네트워크 시뮬레이터에 적용할 수 있는 전력모델 개발과정에 대해 소개한다. 전력모델링에 사용된 센서노드는 ATmega128L과 CC2420으로 구성된 Nano-24노드이다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.9 s.252
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• pp.898-904
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• 2006

A new method measuring thermal conductivity of fluids is proposed in this research. It is based on the steady state heat transfer from a hot central cylinder to a cold outer cylinder located concentrically. This method guarantees more stable measurement than conventional THM(transient hot-wire method) due to its simplicity of theoretical principle. Measurements was made for the three nanofluid samples with different particle concentration of pure, 2% and 4%. Nanofluids are made by mixing the pure transformer oil with AlN nano particles. Design of the sensor module and experimental procedures are explained and comparison of the measuring data between present method and THM was made in detail.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.2
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• pp.112-115
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• 2011

To stabilize the electric characteristic of Silicon Thin Film Transistor, reducing the current leakage is most important issue. To reduce the current leakage, many ideas were suggested. But the increase of mask layer also increased the cost. On this research Bird's Beak process was use to present element. Using Silvaco simulator, it was proven that it was able to reduce current leakage without mask layer. As a result, it was possible to suggest the structure that can reduce the current leakage to 1.39nA without having mask layer increase. Also, I was able to lead the result that electric characteristic (on/off current ratio) was improved compare from conventional structure.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.1274-1276
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• 2017

최근 연구조사에 의하면 전세계에서 배출되는 하루 평균 쓰레기는 450만톤으로 그 양이 해마다 증가하고 있는 실정이다. 쓰레기는 환경오염, 전염병 발생 국가적인 경제적 손실 등과 같은 심각한 문제를 발생시키는 주요원인이기도 하다. 이러한 상황에 대해 최근 다양한 방법으로 쓰레기를 줄이기 위한 연구 등의 노력이 이루어지고 있는 실정이다[1]. 본 연구팀은 저비용 고효율의 효율적 시스템을 구성할 수 있는 IoT 센서와 아두이노를 활용하여 쓰레기를 줄일수록 유도할 수 있는 스마트 쓰레기통을 개발하고자 하였다. 쓰레기가 생산되는 것을 실시간 데이터화하고 이를 활용해 사용자 실시간 알림과 같은 서비스를 구성할 수 있었다.

• Journal of Plant Biotechnology
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• v.33 no.3
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• pp.223-231
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• 2006

Nanobiotechnology, the interdisciplinary area at the crossroad of biotechnology and nanoscience, combines contributions from molecular and cell biology, chemisty, material science, and physics in an attempt to understand the behavior of nanobiomaterials, their development and applications. At present, nanobiotechnology is believed to hold great promise for improving health and prolonging life, faciliating biomarker discovery, molecular diagnostics, discovery of novel drugs and drug delivery, which are important basic components of biomedical science. In the recent trend of nanobiotechnology, this review is intended to provide a better understanding of nanobiotechnology in its applications and perspectives, separating this integration technology into three parts such as nanobiochip/sensor, nanobiomaterials, and nanobioanalysis in order to hopefully gain insights into why size matters, how nano-materials and -devices can be engineered.

• Journal of Sensor Science and Technology
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• v.15 no.4
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• pp.245-250
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• 2006

In this paper, glass cap wafer for MEMS device package is fabricated by using sand blaster dry etcher and Its surface is studied. The surface of dry etched glass is analyzed by using SEM, and many glass particles and micro cracks are observed. If these kind of particles were dropped from glass to the surface of device, It would make critical failure to the operation of device. So, several cleaning and etching methods are induced to remove these kinds of dormant failure mode and optimized condition is found out.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06b
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• pp.223-227
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• 2007

무선 센서 네트워크는 유비쿼터스 컴퓨팅에서 생활환경과 컴퓨터 사이의 중계자 역할을 하는 매우 중요한 연구 분야이다. 매우 제약적인 자원 환경에서 동작하여야 하는 센서 노드의 특성 때문에 제한된 자원을 효율적으로 관리할 수 있는 센서 노드용 운영체제가 요구된다. 또한 센서 네트워크는 외부 물리 환경의 변화에 반응하여 동작하는 시스템이기 때문에 여러 이벤트를 동시에 재빠르게 처리 할 수 있는 기능을 제공해야 하며, 센서네트워크 어플리케이션 프로그래머에게 이러한 반응형 어플리케이션 개발이 용의하도록 하는 프레임워크를 제공해야 한다. 이를 위해 본 논문에서는 반응형 시스템에 적합한 상태머신 프레임 워크를 멀티쓰레드 기반의 Nano-Qplus 운영체제 상에서 센서 네트워크의 자원적 제약을 준수하면서 효율적으로 이벤트를 처리 할 수 있는 프레임워크를 지원하는 센서네트워크용 운영체제의 구조를 제안한다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1375-1376
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• 2007

A synthesized 21-mer single-stranded DNA(ss DNA) was covalently immobilized onto a self-assembled aminoethanethiol monolayer modified gold electrode onto QCM. The covalently immobilized ssDNA was hybridized with complementary ssDNA. The interaction between surface immobilized ssDNA and complementary 21-mer DNA in solution was also examined. Each step was followed by monitoring changes in the QCM frequency with time. Also, PBS with pH 7.0 was selected as a supporting electrolyte in order to get maximum sensitivity and good bioactivity.