• Title/Summary/Keyword: Bio-Nano

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Atomistic analysis of nano/micro biosensors

  • Chen, James;Lee, James D.
    • Interaction and multiscale mechanics
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    • v.3 no.2
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    • pp.111-121
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    • 2010
  • Dynamic analysis of nano/micro bio-sensors based on a multiscale atomistic/continuum theory is introduced. We use a generalized atomistic finite element method (GAFEM) to analyze a bio-sensor which has $3{\times}N_a{\times}N_p$ degrees of freedom, where $N_p$ is the number of representative unit cells and $N_a$ is the number of atoms per unit cell. The stiffness matrix is derived from interatomic potential between pairs of atoms. This work contains two studies: (1) the resonance analysis of nano bio-sensors with different amount of target analyte and (2) the dependence of resonance frequency on finite element mesh. We also examine the Courant-Friedrichs-Lewy (CFL) condition based on the highest resonance frequency. The CFL condition is the criterion for the time step used in the dynamic analysis by GAFEM. Our studies can be utilized to predict the performance of micro/nano bio-sensors from atomistic perspective.

Transmission Electron Microscope Sampling Method for Three-Dimensional Structure Analysis of Two-Dimensional Soft Materials

  • Lee, Sang-Gil;Lee, Ji-Hyun;Yoo, Seung Jo;Datta, Suvo Jit;Hwang, In-Chul;Yoon, Kyung-Byung;Kim, Jin-Gyu
    • Applied Microscopy
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    • v.45 no.4
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    • pp.203-207
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    • 2015
  • Sample preparation is very important for crystal structure analysis of novel nanostructured materials in electron microscopy. Generally, a grid dispersion method has been used as transmission electron microscope (TEM) sampling method of nano-powder samples. However, it is difficult to obtain the cross-sectional information for the tabular-structured materials. In order to solve this problem, we have attempted a new sample preparation method using focused ion beam. Base on this approach, it was possible to successfully obtain the electron diffraction patterns and high-resolution TEM images of the cross-section of tabular structure. Finally, we were able to obtain three-dimensional crystallographic information of novel zeolite nano-crystal of the tabular morphology by applying the new sample preparation technique.

Preparation and Characterization of the Impregnation to Porous Membranes with PVA/PSSA-MA/THS-PSA for Fuel Cell Applications (연료전지 응용을 위한 다공성막에 가교된 PVA/PSSA-MA/THS-PSA의 함침을 통한 고내구성 이온교환막의 제조 및 특성 연구)

  • Kim, Il-Hyoung;Kim, Sung-Pyo;Lee, Hak-Min;Park, Chan-Jong;Rhim, Ji-Won;Cheong, Seong-Ihl
    • Membrane Journal
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    • v.21 no.3
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    • pp.299-305
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    • 2011
  • This study deals with the preparation of polymeric electrolyte membranes having high durability for the application of fuel cells. The membranes under investigation were prepared the impregnation to porous polyethylene membranes with poly(vinyl alcohol)(PVA), poly(styrene sulfonic acid-co-maleic acid), and (PSSA-MA)3-(trihydroxysilyl)-1-propanesulfonic acid (THS-PSA). To characterize the resulting membranes, the water contents, the contact angles, FT-IR, the proton conductivity and the the modulus were measured. The proton conductivity of 30% content of THS-PSA at $55^{\circ}C$ gave excellent $1.27{\times}10^{-1}S/cm$ and the mechanical strength was improved 7 times higher up to the THS-PSA content 15%, as a result, the durability was elevated extensively.

Biosensors: a review (바이오센서)

  • Hwang, Kyo-Seon;Kim, Sang-Kyung;Kim, Tae-Song
    • Journal of Sensor Science and Technology
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    • v.18 no.4
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    • pp.251-262
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    • 2009
  • Biosensors exploit the specific binding between recognition molecule on the biosensor surface and target molecule in analyte and are used in the detection of specific biomolecules such as protein, DNA, cell, virus, etc., with a view towards developing analytical devices. Recently, application field of biosensors have been expanding from diagnosis to biodefense because they can basically serve as high performance devices. This review describes the basic information of biosensors including definition, classification, and operational principle. Moreover, we introduce micro/nano technology-based biosensors with better detection performance than traditional method and their application examples.