• Title/Summary/Keyword: Specific Film Thickness

Search Result 90, Processing Time 0.028 seconds

Development of Active thin Film Optical Waveguide $C^{2+}$ -ion Sensor (능동형 박막 광도파로 칼슘 이온 센서의 개발)

  • Lee, Su-Mi;Gang, Sin-Won
    • Journal of the Institute of Electronics Engineers of Korea SC
    • /
    • v.37 no.4
    • /
    • pp.49-54
    • /
    • 2000
  • A new functional organic thin film optical waveguide ion sensor is designed, which can select a specific ion, i.e., $Ca^{2+}$ -ion. The sensing membrane was composed of PVC-PVAC-PVA copolymer matrix based on anionic cation-selective chromoionophor(ETH5294), neutral ionophore(K23El), anionic site and plasticizer and it was coated on the etched glass substrate as embeded type optical waveguide itself. The sensor sensitivity dependence on waveguide length and thickness, contence of chromoionophore, and each mode was investigated. And this sensor could detect $Ca^{2+}$ ion in concentrations ranging from 1$\times$10­6~1M(with 0.05M tris-HCI buffer solution of pH7.4) by measuring the absorbance change at 514nm of light. Utilizing thin film membrane, the fast response time and high sensitivity are obtained. Also, it is expected that this sensor can be applied to various biochemical important ions.ons.

  • PDF

Indium Tin Oxide (ITO) Nano Thin Films Deposited by a Modulated Pulse Sputtering at Room Temperature (모듈레이티드 펄스 스퍼터링으로 상온 증착한 Indium-Tin-Oxide (ITO) 나노 박막)

  • You, Younggoon;Jeong, Jinyong;Joo, Junghoon
    • Journal of the Korean institute of surface engineering
    • /
    • v.47 no.3
    • /
    • pp.109-115
    • /
    • 2014
  • High power impulse magnetron sputtering (HIPIMS), also known as the technology is called peak power density in a short period, you can get high, so high ionization sputtering rate can make. Higher ionization of sputtered species to a variety of coating materials conventional in the field of improving the characteristics and self-assisted ion thin film deposition process, which contributes to a superior being. HIPIMS at the same power, but the deposition speed is slow in comparison with DC disadvantages. Since recently as a replacement for HIPIMS modulated pulse power (MPP) has been developed. This ionization rate of the sputtered species can increase the deposition rate is lowered and at the same time to overcome the problems to be reported. The differences between the MPP and the HIPIMS is a simple single pulse with a HIPIMS whereas, MPP is 3 ms in pulse length is adjustable, with the full set of multi-pulses within the pulse period and the pulse is applied can be micro advantages. In this experiment, $In_2O_3$ : $SnO_2$ composition ratio of 9 : 1 wt% target was used, Ar : $O_2$ flow rate ratio is 4.8 to 13.0% of the rate of deposition was carried out at room temperature. Ar 40 sccm and the flow rate of $O_2$ and then fixed 2 ~ 6 sccm was compared against that. The thickness of the thin film deposition is fixed at 60 nm, when the partial pressure of oxygen at 9.1%, the specific resistance value of $4.565{\times}10^{-4}{\Omega}cm$, transmittance 86.6%, mobility $32.29cm^2/Vs$ to obtain the value.

Fabrication of Ex vivo Cornea Model for a Drug Toxicity Evaluation (약물 독성 평가용 생체외 각막 모델 제작 연구)

  • Kim, Seon-Hwa;Park, Sang-Hyug
    • Journal of Biomedical Engineering Research
    • /
    • v.40 no.5
    • /
    • pp.143-150
    • /
    • 2019
  • To evaluate the toxicity of ophthalmic drug, the Draize test and Bovine Corneal Opacity and Permeability (BCOP) test commonly used. In Draize test, experimental animals were under stress and pain due to long-term exposure of drug. In addition, regarding physiological functions, animal model is not perfectly reflected a human eye condition. Although some models such as $EpiOcular^{TM}$, HCE model, LabCyte Cornea-Model, and MCTT $HCE^{TM}$ were already presented advanced cornea ex-vivo model to replace animal test. In this sense, cornea tissue structure mimicked ex-vivo toxicity model was fabricated in this study. The corneal epithelial cells (CECs) and keratocytes (CKs) isolated from rabbit eyeball were seeded on non-patterned silk film (n-pSF) and patterned silk film (pSF) at $32,500cells/cm^2$ and $6,500cells/cm^2$. Sequentially, n-pSF and pSF were stacked to mimic a multi-layered stroma structure. The thickness of films was about $15.63{\mu}m$ and the distance of patterns was about $3{\mu}m$. H&E stain was performed to confirm the cell proliferation on silk film. F-actin of CKs was also stained with Phalloidin to observe the cytoskeletal alignment along with patterns of the pSF. In the results, CECs and CKs were shown the good cell attachment on the n-pSF and pSFs. Proliferated cells expressed the specific phenotype of cornea epithelium and stroma. In conclusion, we successfully established the ex-vivo cornea toxicity model to replace the eye irritation tests. In further study, we will set up the human ex-vivo cornea toxicity model and then will evaluate the drug screening efficacy.

Evaluations of Si based ternary anode materials by using RF/DC magnetron sputtering for lithium ion batteries

  • Hwang, Chang-Muk;Park, Jong-Wan
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2010.08a
    • /
    • pp.302-303
    • /
    • 2010
  • Generally, the high energy lithium ion batteries depend intimately on the high capacity of electrode materials. For anode materials, the capacity of commercial graphite is unlike to increase much further due to its lower theoretical capacity of 372 mAhg-1. To improve upon graphite-based negative electrode materials for Li-ion rechargeable batteries, alternative anode materials with higher capacity are needed. Therefore, some metal anodes with high theoretic capacity, such as Si, Sn, Ge, Al, and Sb have been studied extensively. This work focuses on ternary Si-M1-M2 composite system, where M1 is Ge that alloys with Li, which has good cyclability and high specific capacity and M2 is Mo that does not alloy with Li. The Si shows the highest gravimetric capacity (up to 4000mAhg-1 for Li21Si5). Although Si is the most promising of the next generation anodes, it undergoes a large volume change during lithium insertion and extraction. It results in pulverization of the Si and loss of electrical contact between the Si and the current collector during the lithiation and delithiation. Thus, its capacity fades rapidly during cycling. Si thin film is more resistant to fracture than bulk Si because the film is firmly attached to the substrate. Thus, Si film could achieve good cycleability as well as high capacity. To improve the cycle performance of Si, Suzuki et al. prepared two components active (Si)-active(Sn, like Ge) elements film by vacuum deposition, where Sn particles dispersed homogeneously in the Si matrix. This film showed excellent rate capability than pure Si thin film. In this work, second element, Ge shows also high capacity (about 2500mAhg-1 for Li21Ge5) and has good cyclability although it undergoes a large volume change likewise Si. But only Ge does not use the anode due to its costs. Therefore, the electrode should be consisted of moderately Ge contents. Third element, Mo is an element that does not alloys with Li such as Co, Cr, Fe, Mn, Ni, V, Zr. In our previous research work, we have fabricated Si-Mo (active-inactive elements) composite negative electrodes by using RF/DC magnetron sputtering method. The electrodes showed excellent cycle characteristics. The Mo-silicide (inert matrix) dispersed homogeneously in the Si matrix and prevents the active material from aggregating. However, the thicker film than $3\;{\mu}m$ with high Mo contents showed poor cycling performance, which was attributed to the internal stress related to thickness. In order to deal with the large volume expansion of Si anode, great efforts were paid on material design. One of the effective ways is to find suitably three-elements (Si-Ge-Mo) contents. In this study, the Si based composites of 45~65 Si at.% and 23~43 Ge at.%, and 12~32 Mo at.% are evaluated the electrochemical characteristics and cycle performances as an anode. Results from six different compositions of Si-Ge-Mo are presented compared to only the Si and Ge negative electrodes.

  • PDF

Comparison of the specific migration values from various plastic food packaging materials being used for fatty food and at high temperature obtained by using testing methods as prescribed in the regulations of different country areas (각 국가 권역별 이행 실험방법에 따른 지방성 및 고온가열 식품포장재에서의 특정이행량 비교 조사)

  • Lee, Keun-Taik;Kim, Dong-Joo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
    • /
    • v.8 no.1
    • /
    • pp.1-10
    • /
    • 2002
  • The actual specific migration data for antioxidants and di-ethylhexyl adipate from plastic food packaging materials being used for fatty food and at high temperature into various food simulants were obtained and compared in accordance with the testing methods and conditions in EU, USA and Korea or Japan. In the case of food packaging material for high temperature use, especially in a thick film such as polypropylene in $450{\mu}m$ thickness, a significant difference in the migration value for antioxidants was observed depending on the migration testing condition and simulants used as defined in the each country areas. Considering the reduction factor of 2 to 5 as being currently applied in EU and USA regulations, the migration values obtained by testing methods of Korea or Japan can exhibit actually higher than those of EU and USA. The migration testing conditions are required to be specified diversely according to the actual exposure temperature of packaging materials.

  • PDF

Preparation of $SrTiO_3$ Thin Film by RF Magnetron Sputtering and Its Dielectric Properties (RF 마그네트론 스퍼터링법에 의한 $SrTiO_3$박막제조와 유전특성)

  • Kim, Byeong-Gu;Son, Bong-Gyun;Choe, Seung-Cheol
    • Korean Journal of Materials Research
    • /
    • v.5 no.6
    • /
    • pp.754-762
    • /
    • 1995
  • Strontium titanate(SrTiO$_3$) thin film was prepared on Si substrates by RF magnetron sputtering for a high capacitance density required for the next generation of LSTs. The optimum deposition conditions for SrTiO$_3$thin film were investigated by controlling the deposition parameters. The crystallinity of films and the interface reactions between SrTO$_3$film and Si substrate were characterized by XRD and AES respectively. High quality films were obtained by using the mixed gas of Ar and $O_2$for sputtering. The films were deposited at various bias voltages to obtain the optimum conditions for a high quality file. The best crystallinity was obtained at film thickness of 300nm with the sputtering gas of Ar+20% $O_2$and the bias voltage of 100V. The barrier layer of Pt(100nm)/Ti(50nm) was very effective in avoiding the formation of SiO$_2$layer at the interface between SrTiO$_3$film and Si substrate. The capacitor with Au/SrTiO$_3$/Pt/Ti/SiO$_2$/Si structure was prepared to measure the electric and the dielectric properties. The highest capacitance and the lowest leakage current density were obtained by annealing at $600^{\circ}C$ for 2hrs. The typical specific capacitance was 6.4fF/$\textrm{cm}^2$, the relative dielectric constant was 217, and the leakage current density was about 2.0$\times$10$^{-8}$ A/$\textrm{cm}^2$ at the SrTiO$_3$film with the thickness of 300nm.

  • PDF

Photoelectrochemical Properties of $TiO_2$-Phthalocyanine Thin Film System (Ⅰ) (산화티탄-프탈로시아닌계의 광전기화학적 성질 (Ⅰ))

  • Jin, E.;Kim, Y.S.;Fujishima, Akira
    • Journal of the Korean Chemical Society
    • /
    • v.42 no.1
    • /
    • pp.42-50
    • /
    • 1998
  • Titanium dioxide $(TiO_2)$ thin film samples were prepared by using spray pyrolysis methodology and were by using X-ray photoelectron spectroscopy and X-ray diffraction analysis. It was found that anatase prepared by the hydrolysis of titanium(Ⅳ) oxyacetylacetonate exhibited the largest specific surface area. The particle size increased with increasing temperature, while the thickness decreased. Titanium dioxide $(TiO_2)$ in the anatase form was prepared at $400^{\circ}C$ and the photoconductivity was determined using photocurrent measurements. Photoelectrochemical properties of the $TiO_2$-phthalocyanine system were measured in a three-electrode system. The photocurrent action spectrum in the visible region coincided with intrinsic absorption spectrum of phthalocyanine. The crystal structure of phthalocyanine is considered to be a very important property in the photogeneration phenomena.

  • PDF

The Specific Case Analysis of Biomineralization Induced by Sulfate Reducing Bacteria

  • Liu, Hongwei;Qin, Shuang;Fu, Chaoyang;Xiao, Fei;Wang, Deli;Han, Xia;Wang, Tianli;Liu, Hongfang
    • Corrosion Science and Technology
    • /
    • v.16 no.6
    • /
    • pp.285-293
    • /
    • 2017
  • The effects of sulfate reducing bacteria (SRB) on the corrosion and scaling of the Q235 carbon steel has been investigated in the simulated sewage water and oil field gathering pipelines production water, using scanning electron microscopy (SEM), energy dispersive x-ray spectrometry (EDS), and three-dimensional stereoscopic microscope. Results indicated that the concentration of SRB reached the maximum value on the ninth day in simulated sewage water with a large amount of scaling on the surface of specimen. In oil field gathering pipelines, a large amount of scaling and mineralization of mineral salts and thick deposition of extracellular polymeric substance (EPS) layers were also observed on the surface of specimen. The thickness of biofilm was about $245{\mu}m$ within 30 days. After adding microbicides, the thickness of corrosion products film was only up to $48-106{\mu}m$ within 30 days, suggesting that SRB could induce biomineralization. Under-deposit corrosion morphology was uniform in the absence of microbicides while local corrosion was observed in the presence of microbicides.

High Power Characteristics of Amorphous $MnO_2$ Electrode by Variation of Electrode Thickness (비정질 $MnO_2$ 전극의 전극두께에 따른 고출력 특성 변화)

  • Seong W. K.;Kim E. S.;Lee H. Y.;Kim S. W.
    • Journal of the Korean Electrochemical Society
    • /
    • v.3 no.4
    • /
    • pp.235-240
    • /
    • 2000
  • Screen-printing and doctor blade method were investigated and proposed as an electrode coating process for high power capacitor. CV measured from the amorphous $MnO_2$ electrode prepared by screen-printing shows closer to ideal capacitor characteristics. Specific capacitances calculated from CVs with potential scan rate of 50mV/s were 5.8, 81.8, and 172.0 F/g for electrode thickness of $140{\mu}m,\;24{\mu}m,\; 3{\mu}m$, respectively. Assumed that utilization of active $MnO_2$ in electrode of screen-printing is $100\%$, those were $3.4\%$ in one of paste method and $47.6\%$ in one of doctor blade method. The screen-printing can be good technique to coat thin film on current collector for high power application.

Development of Low-Cost High-Performance Antibacterial Tempered Glass (저비용 고기능성 항균강화유리 개발을 위한 연구)

  • Kim, Jun-Sub
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.22 no.1
    • /
    • pp.562-567
    • /
    • 2021
  • To develop an antibacterial tempered glass for applications to various building facilities and household products, the antibacterial activity of domestic materials was investigated, and a tempered glass sample was produced with silver, copper, and zinc, having an antibacterial activity of 99% or more at a specific concentration. The measured antibacterial activity of the samples, in which silver, copper, and zinc were dispersed in ethylene glycol + glycerol, was more than 99%. Measurements of the thickness of the coated metal material by washing using a surface analyzer showed that the thickness decreased by less than 1% in various types of detergents, including water, but only approximately 10% in the alkaline detergents. To check the human safety of the samples, a cytotoxicity test was performed through an MTT assay; the samples showed no cytotoxicity. Finally, a Live/Dead kit or film adhesion method showed that the antibacterial activity of the prototype was more than 99%. Therefore, the high-functional antibacterial effect of tempered glass was developed using domestic materials and may be used in various products in the future.