저자는 anodically 질감 알루미늄 마스터와 스위스 연방 에너지 청 및 자금의 스위스 국립 과학 재단 (National Science Foundation)의 AFM, W. 리와 도움 M. Leboeuf 감사드립니다. 이 작품의 일부는 FP7 프로젝트 보​​조금 협정 없음 283,501에서 EC의 지원을받는 &quot;패스트 트랙&quot;의 틀에서 실시되었다.

1. 몰드 제조 우리는. 부정적인 금형 다음 참조의 제조를 위해 6 저희 집 내장 nanoimprinting 설정을 사용하지만, 다른 nanoimprinting 설치 잘 작동합니다. 또는 작용 polydimethylsiloxane (PDMS) 몰드도 작동 할 수 있습니다. <ol><li> 제조 또는 양도 할 수있는 nanoscale 패턴을 가진 적당한 주인을 구입합니다. 원칙적으로 nanoimprinting에 적합합니다 모든 마스터는 일을 할 것입니다. 우리는 방법을 설명하기 위해 마스터 구조로 3.1에서 설명 입금 유리 시트에 질감 ZnO 층 (SCHOTT, AF32 환경, 41mm X 41mm X 0.5 mm)을 사용합니다. </li><li> 등의 2에 설명 된 마스터 구조에 방지 접착 층을 적용합니다. </li><li> 2 개 분을위한 초음파 이소프로판올 욕조 뒤에 2 분을위한 초음파 아세톤 욕조에 폴리에틸렌 naphtalate (PEN) 시트 (Goodfellow, 82mm X 41mm X 0.125 mm)를 청소합니다. 이소프로판올으로 한 번 더 씻어 질소로 건조 버립니다. </li><li> 보증금은 PEN 시트에 크롬 부착 층 (5-10 nm 정도)를 스퍼터링. </li><li> 스핀 코트 5,000 RPM에서 PEN 시트에있는 UV-경화 수지 (Microresist, Ormocer, 1-2 ML)는 균일 한 범위를 가져옵니다. </li><li> 80에서 핫 플레이트에 5 분을위한 prebake을 수행 ° C 용매를 증발하기 위해 PEN 시트에 필름 균일 성과 접착력을 향상시킵니다. </li><li> UV-경화 수지에 마스터 패턴을 도장 할 nanoimprinting 설정을 사용합니다. 의무적되지 않았지만, 우리는 유연한 실리콘 막에 한 줄의 균일 한 압력을 적용하여 거품 흠을 방지하기 위해 진공 스탬핑 수행합니다. 우리의 설치 프로그램에서 실리콘 막 두 하위 구획에 진공 챔버를 분리합니다. 낮은 구획은 진공 하에서 유지하면서 압력은 환기 상단 칸에 의해 생성됩니다. 환기는 스탬프를 시작 하단에 대한 유연한 멤브레인을 등록합니다. </li><li> 수지의 가교 반응을 유도 할 수 UV 빛에 수지 노출. 우리는 적당한 빛을 적용여러 개의 LED가 제공하는 365 nm의 파장에서 1.4 MW / cm 2 강도. PEN 시트를 통해 노출 시간은 일반적으로 15-20 분입니다. </li><li> 조심스럽게 수동으로 마스터 구조에서 금형을 필링으로 demould. </li><li> 수지는 더 처리하기 전에 주변 분위기 오븐에 6-8 시간 동안 필링 자연, 우리는 150에서 가벼운 열 후 베이킹을 수행 ° C로 이어질 수있는 기능 재료의 증착시 약간의 수축을 받아야 수 있기 때문입니다. </li></ol> 2. 안티 - 접착 층 성공 demoulding를 들어, 반 접착 층은 재료와 패턴 거칠기에 적응해야합니다. 일반적으로 거친 패턴은 낮은 고집 계수를 필요로합니다. 부드러운 패턴에 대한 낮은 고집 계수는 금형에서 기능 소재 필링으로 이어질 수 있습니다. 거친 패턴에 대한 높은 고집 계수는 adheren 등의 금형 제조 동안 PEN 시트에서 수지의 필링이 발생할 수 있습니다마스터에 수지의 CE 힘이 있습니다. <ol><li> 코트와 금형 (또는 마스터)는 반 접착 에이전트의 접착력을 홍보하기 위해 크롬 층 (5-10 nm 정도)를 스퍼터링. 부드러운 패턴을 위해이 단계를 놓습니다. 어떤 경우에는 크롬 층은 에칭 마스터 구조 반 접착 에이전트를 방지 할 수 있습니다. </li><li> 유리 슬라이드에 방지 접착 에이전트의 작은 드롭 (시그마 - 알드리치 (1H, 1H, 2H, 2H-Perfluoroctyl) trichlorsilane)를 적용합니다. 진공 챔버에 곰팡이와 함께 유리 슬라이드를 놓고 펌프. 안티 - 접착 에이전트는 증발하고 금형에 분자 monolayer로 입금됩니다. </li><li> 80 1-2 시간 동안 어닐링 ° C.를 통해 반 접착 에이전트를 고정 </li></ol> 3. 물질의 증착 우리는 nanomoulding의 다양성을 설명하려면 여기를 물질의 증착에 적합한 세 증착 기술을 보여줍니다. 다른 증착 기술도 적용 될 수 있습니다. 세 번째 예는 FA를 설명전체 박막 실리콘 태양 전지의 brication. <ol><li> 아연 산화물의 화학 기상 증착 (CVD)는 180로 가열 CVD 반응기의 가열 플레이트 ° C.에 금형을 넣고 ZnO 증착 동안 PEN 금형의 굽힘 방지하기 위해 금속 프레임을 사용합니다. 반응기를 닫고 아래로 펌프 및 thermalization 할 수 있습니다. 전구체 가스 (H 2 O와 (C 2 H 5) 2 아연)을 인정합니다. 도핑에 대한 또한 우리는 복용량 B 2의 소량 H 6. ZnO 층의 두께는 증착 시간에 비례합니다. 우리는 ZnO 층 일반적으로 1-5 μm의 두께를 사​​용합니다. 전형적인 선서 매개 변수에 대한 자세한 내용은이 심판에서 찾을 수 있습니다. 7 </li><li> 물리적 기상 증착 (PVD) / 실버의 스퍼터링은 : PVD ​​시스템에 금형을 놔. 시스템을 종료하고 아래로 펌프. 아르곤 프로세스 가스를 인정합니다. DC 발전기를 켭니다. 자세 층의 두께가 다시 증착 시간에 비례합니다. 우리는 자세 층 일반적으로 1 μm의 두께를 사​​용합니다. 일반적인 증착 Parameters는 5.5x10 -3 mbar의 아르곤 압력과 약 45 nm의 / 초의 증착 속도를 항복 250 W의 설정 특정 DC 전원입니다. </li><li> 플라즈마 강화 화학 기상 증착 (PE-CVD) : 3.1에서와 같이 보증금 ZnO). 200 가열 PE-CVD 반응기 ° C.에 금형을 넣어 반응기를 닫고 아래로 펌프 및 thermalization 할 수 있습니다. 전구체 가스 (SiH 4 H 2) 인정합니다. 또한 우리는 복용량 B 적은 양의 (CH 3) 3과 각각 P와 N-타입 도핑을 달성 할 PH 3.을 태양 전지의 개방 회로 전압을 증가하기 위해, 우리는 또한 도핑 된 층에 CH 4와 CO 2의 소량을 사용합니다. 3.1에서 설명 된대로 핀 비정질 실리콘 태양 전지 스택의 증착 한 후, 우리는 ZnO의 backcontact을 입금. </li><li> 벤딩하면 증착 층의 필링가 발생할 수 있습니다와 같은 몰드의 과도한 굽힘을 피하십시오. </li></ol> 4. 레이어 전송 우리는 glas를 사용최종 기판 등의 슬라이드 (SCHOTT AF32 환경, 41mm X 41mm X 0.5 mm). 그러나 금속 포일 또는 고분자 시트를 포함한 다른 기판은, 대안 사용될 수있다. <ol><li> 아세톤 및 이소프로판올과 질소로 건조 타격과 깨끗한 유리 슬라이드. </li><li> 5000 rpm에서의 유리 슬라이드에 스핀 코트는 UV-경화 수지 (Microresist, Ormocer, 1-2 ML). </li><li> 최종 기판에 증착 된 레이어를 들고 틀을 고정 할 nanoimprinting 설정을 사용합니다. 스탬핑에 관해서는, 우리는 1 줄의 균일 한 압력을 적용하여 진공 하에서 고정 수행합니다. </li><li> 교차 연결 반응을 유도 할 수 UV 빛에 수지 노출. 우리는 여러 개의 LED가 제공하는 365 nm의 파장에서 1.4 MW / cm 2의 적당한 강도를 적용 할 수 있습니다. 유리 슬라이드를 통해 노출 시간은 PEN에 비해 유리의 높은 UV 전송으로 인해 1-3 위에 만 분입니다. </li><li> 수동으로 유리 슬라이드에서 금형을 필링으로 Demould. </li></ol> 5. 샘플 특성 <ol&gt; <li> nanomoulded 샘플을 특성화하기 위해 좋아하는 형태학의, 전기 또는 광학 기술을 사용합니다. 여기 스캔 전자 현미경 (SEM)과 원자 힘 현미경 (AFM)을 사용하여 우리 nanomoulded 샘플을 특성화한다. </li></ol>

<ol>
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관심 없음 충돌이 선언 없습니다.

Nanomoulding은 임의의 기능성 물질에 대한 nanopatterns의 전송이 가능합니다. 그림 1과 2의 개별 처리 단계의 비교는 nanomoulding와 nanoimprinting 사이의 긴밀한 관계를 보여준다. nanomoulding와 nanoimprinting 사이의 큰 차이는 그림 2e의 추가 물질의 증착 단계입니다. 나머지 프로세스 흐름은 동일합니다. Nanomoulding 따라서 가능한 nanoimprinting 설정에 수행 할 수 있습니다. <p class="jove_cont...

Nanopatterning는 나노 기술 및 응용 과학의 많은 분야에서 엄청난 중요성을 얻었습니다. 패턴 생성의 첫 단계이며, 이러한 예 nanosphere 리소그래피 또는 블록 공중 합체 리소그래피 1로 자기 조립 방법에 따라 전자 - 빔 리소그래피 또는 상향식 접근 방식과 같은 하향식 (top-down) 접근 방식에 의해 수행 될 수있다. 패턴 생성만큼이나 중요 패턴 복제입니다. 석판 술 외에, nanoimprinting (그림 1)은 저렴한 비용으로 2-4의 높은 처리량 대형 지역 nanoscale 패턴에 적합한 특히 유망 대안으로 떠오르고있다. 석판 술이 패턴 마스크를 필요로하지만, nanoimprinting는 조립식 마스터 구조에 의존하고 있습니다. 마스터에서 패턴 전송은 일반적으로 열가소성 또는 UV 또는 열 경화 ​​폴리머로 수행됩니다. 가 직접 기능 소재에 패턴을 전송하는 것이 바람직입니다 그러나 대부분의 경우가 마련되어 있습니다. &lt;P 클래스 = &quot;jove_content&quot;&gt; 다음은 nanomoulding 우리는 최근 참조에 도입 된 계층 전송 (그림 2)에 따라 복제 방법을 설명합니다. 5 기능 아연 산화물 전극에 nanoscale 패턴을 전송할 수 있습니다. nanoimprinting 설정을 사용할 경우 우리 nanomoulding 방법은 쉽게 구현 될 수있다. Nanomoulding는 금형 소재는 물질의 증착 공정 (ES)와 호환되도록 선택되어 제공 많은 다른 기능 재료, 재료 스택, 심지어 완전한 장치에 일반화 될 수있는 가능성을 제공합니다. 예를 들어 우리가 여기 다섯 태양 전지에 빛을 트래핑을 향상시키기위한 자신의 응용 프로그램을 찾을 화학 기상 증착 (CVD)에 의해 증착 투명 전도성 아연 산화물 (ZnO) 전극의 nanomoulding 제시한다.

<table border="1"><tbody><tr><td> 시약의 이름 </td><td> 회사 </td><td> 카탈로그 번호 </td><td> 코멘트 (선택 사항) </td></tr><tr><td> Nanoimprinting 수지 </td><td> Microresist </td><td> Ormostamp </td><td></td></tr><tr><td> (1H, 1H, 2H, 2H-Perfluoroctyl) trichlorsilane, 항 부착 에이전트 </td><td> 시그마 알드리치 </td><td> 448931-10G </td><td></td></tr><tr><td> 유리 슬라이드 </td><td> SCHOTT </td><td> AF32 환경 </td><td> 0.5 mm </td></tr><tr><td> 폴리에틸렌 naphtalate (PEN) 시트 </td><td> Goodfellow </td><td> ES361090 </td><td> 0.125 mm </td></tr><tr><td> (C 2 H 5) 2 아연 </td><td> Akzo 노벨 </td><td></td><td></td></tr><tr><td> 자세 대상 4N 스퍼터 </td><td> Heraeus </td><td> 81062165 </td><td></td></tr><tr><td> B 2 H 6, SiH 4, H 2, B (CH 3) 3, PH 3, CH 4, CO 2 </td><td> 메서 </td><td></td><td></td></tr><tr><td></td><td></td><td></td><td> 장비 </td></tr><tr><td> 시스템을 Nanoimprinting </td><td> 홈 구축 </td><td></td><td></td></tr><tr><td> LP-CVD 시스템 </td><td> 홈 구축 </td><td></td><td></td></tr><tr><td> PVD 시스템 </td><td> Leybold </td><td> Univex 450 B </td><td></td></tr><tr><td> PE-CVD 반응기 </td><td> Indeotec </td><td> 문어 I </td><td></td></tr><tr><td> SEM </td><td> JEOL </td><td> JSM-7500 TFE </td><td></td></tr><tr><td> AFM </td><td> 디지털 기기 </td><td> Nanoscope 3100 </td><td></td></tr></tbody></table>

nanomoulding of functional materials, a versatile complementary pattern replication method to nanoimprinting

우리는 기능 재료, 재료 스택 및 전체 장치의 저가 nanoscale 패턴을 허용 nanomoulding 기술을 설명합니다. 레이어 전송과 결합 Nanomoulding는 기능 소재로 마스터 구조에서 임의의 표면 패턴의 복제 수 있습니다. Nanomoulding는 모든 nanoimprinting 설정에서 수행 할 수 있으며, 자료 및 증착 공정의 다양한 범위에 적용 할 수 있습니다. 특히 우리는 태양 전지에 빛을 포집 애플리케이션을 위해 패턴 투명 아연 산화물 전극의 제조를 보여줍니다.

<html> 그림 3은 nanomoulded 구조의 일부 설명 예제를 요약 한 것입니다. 유리에 CVD에 의해 성장 ZnO 마스터 구조는 ()로 표시됩니다. 해당 nanomoulded ZnO 복제는 (D)로 표시됩니다. 지역 높이 (g)와 AFM 이미지에서 추출한 각도 (J) histograms의 비교는 nanomoulding 과정의 고 충실도을 알 수있다. 유사한 결과는 간섭 리소그래피 (B, E, H, K) 및 anodically 질감 알루미늄 (C, F, I, L)에 의해 제조 한 차원 격자에 ?...

Watch this Scientific Journal Video about Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting at JoVE.com

Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting

우리는 기능 재료, 재료 스택 및 전체 장치의 저가 nanoscale 패턴을 허용 nanomoulding 기술을 설명합니다. Nanomoulding는 모든 nanoimprinting 설정에서 수행 할 수 있으며, 자료 및 증착 공정의 다양한 범위에 적용 할 수 있습니다.

기능성 재료 Nanomoulding, Nanoimprinting에 다목적 보완 패턴 복제 방법

We describe a nanomoulding technique which  allows low-cost nanoscale patterning of functional materials, materials stacks  and full devices. Nanomoulding ...

nanomoulding-functional-materials-versatile-complementary-pattern

Research

JoVE Journal

Engineering

11.6K 조회수.  Ecole Polytechnique Fédérale de Lausanne (EPFL). 우리는 기능 재료, 재료 스택 및 전체 장치의 저가 nanoscale 패턴을 허용 nanomoulding 기술을 설명합니다. Nanomoulding는 모든 nanoimprinting 설정에서 수행 할 수 있으며, 자료 및 증착 공정의 다양한 범위에 적용 할 수 있습니다.

비디오: Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting

Using Neutron Spin Echo Resolved Grazing Incidence Scattering to Investigate Organic Solar Cell Materials

The spin echo resolved grazing incidence scattering (SERGIS) technique has been used to probe the length-scales associated with irregularly shaped crystallites. Neutrons are passed through two well defined regions of magnetic field; one before and one after the sample. The two magnetic field regions have opposite polarity and are tuned such that neutrons travelling through both regions, without being perturbed, will undergo the same number of precessions in opposing directions. In this case the neutron precession in the second arm is said to &#34;echo&#34; the first, and the original polarization of the beam is preserved. If the neutron interacts with a sample and scatters elastically the path through the second arm is not the same as the first and the original polarization is not recovered. Depolarization of the neutron beam is a highly sensitive probe at very small angles (&#60;50&#160;&#956;rad) but still allows a high intensity, divergent beam to be used. The decrease in polarization of the beam reflected from the sample as compared to that from the reference sample can be directly related to structure within the sample.
In comparison to scattering observed in neutron reflection measurements the SERGIS signals are often weak and are unlikely to be observed if the in-plane structures within the sample under investigation are dilute, disordered, small in size and polydisperse or the neutron scattering contrast is low. Therefore, good results will most likely be obtained using the SERGIS technique if the sample being measured consist of thin films on a flat substrate and contain scattering features that contains a high density of moderately sized features (30 nm to 5 &#181;m) which scatter neutrons strongly or the features are arranged on a lattice. An advantage of the SERGIS technique is that it can probe structures in the plane of the sample.

Progress has been made in utilizing spin echo resolved grazing incidence scattering (SERGIS) as a neutron scattering technique to probe the length-scales in irregular samples. Crystallites of [6,6]-phenyl-C61-butyric acid methyl ester have been probed using the SERGIS technique and the results confirmed by optical and atomic force microscopy.

중성자 스핀 에코 사용 하 여 방목 발생률 을 해결 하는 유기 태양 전지 물질을 조사 하기 위해

The spin echo resolved grazing incidence scattering (SERGIS) technique has been used to probe the length-scales associated with irregularly shaped ...

연구

공학

Casting Protocols for the Production of Open Cell Aluminum Foams by the Replication Technique and the Effect on Porosity

Metal foams are interesting materials from both a fundamental understanding and practical applications point of view. Uses have been proposed, and in many cases validated experimentally, for light weight or impact energy absorbing structures, as high surface area heat exchangers or electrodes, as implants to the body, and many more. Although great progress has been made in understanding their structure-properties relationships, the large number of different processing techniques, each producing material with different characteristics and structure, means that understanding of the individual effects of all aspects of structure is not complete. The replication process, where molten metal is infiltrated between grains of a removable preform material, allows a markedly high degree of control and has been used to good effect to elucidate some of these relationships. Nevertheless, the process has many steps that are dependent on individual &#8220;know-how&#8221;, and this paper aims to provide a detailed description of all stages of one embodiment of this processing method, using materials and equipment that would be relatively easy to set up in a research environment. The goal of this protocol and its variants is to produce metal foams in an effective and simple way, giving the possibility to tailor the outcome of the samples by modifying certain steps within the process. By following this, open cell aluminum foams with pore sizes of 1&#8211;2.36 mm diameter and 61% to 77% porosity can be obtained.

Replication is one of the processing techniques used for the production of porous metal sponges. In this paper one implementation of the method for the production of open celled porous aluminum is shown in detail.

복제 기술에 의해 오픈 셀 알루미늄 발포체의 생산 및 기공의 효과에 대한 프로토콜 캐스팅

Metal foams are interesting materials from both a fundamental understanding and practical applications point of view. Uses have been proposed, and in many ...

Preparation and Reactivity of Gasless Nanostructured Energetic Materials

High-Energy Ball Milling (HEBM) is a ball milling process where a powder mixture placed in the ball mill is subjected to high-energy collisions from the balls. Among other applications, it is a versatile technique that allows for effective preparation of gasless reactive nanostructured materials with high energy density per volume (Ni+Al, Ta+C, Ti+C). The structural transformations of reactive media, which take place during HEBM, define the reaction mechanism in the produced energetic&#160;composites. Varying the processing conditions permits fine tuning of the milling-induced microstructures of the fabricated composite particles. In turn, the reactivity, i.e., self-ignition temperature, ignition delay time, as well as reaction kinetics, of high energy density materials depends on its microstructure. Analysis of the milling-induced microstructures suggests that the formation of fresh oxygen-free intimate high surface area contacts between the reagents is responsible for the enhancement of their reactivity. This manifests itself in a reduction of ignition temperature and delay time, an increased rate of chemical reaction, and an overall decrease of the effective activation energy of the reaction. The protocol provides a detailed description for the preparation of reactive nanocomposites with tailored microstructure using short-term HEBM method. It also describes a high-speed thermal imaging technique to determine the ignition/combustion characteristics of the energetic materials. The protocol can be adapted to preparation and characterization of a variety of nanostructured energetic composites.

This protocol describes the preparation of gasless nanostructured energetic materials (Ni+Al, Ta+C, Ti+C) using the short-term high-energy ball milling (HEBM) technique. It also describes a high-speed thermal imaging method to study the reactivity of mechanically fabricated nanocomposites. These protocols can be extended to other reactive nanostructured energetic materials.

준비 및 Gasless 나노 구조의 반응성 정력 재료

High-Energy Ball Milling (HEBM) is a ball milling process where a powder mixture placed in the ball mill is subjected to high-energy collisions from the ...

Synthesis and Functionalization of 3D Nano-graphene Materials: Graphene Aerogels and Graphene Macro Assemblies

Efforts to assemble graphene into three-dimensional monolithic structures have been hampered by the high cost and poor processability of graphene. Additionally, most reported graphene assemblies are held together through physical interactions (e.g., van der Waals forces) rather than chemical bonds, which limit their mechanical strength and conductivity. This video method details recently developed strategies to fabricate mass-producible, graphene-based bulk materials derived from either polymer foams or single layer graphene oxide. These materials consist primarily of individual graphene sheets connected through covalently bound carbon linkers. They maintain the favorable properties of graphene such as high surface area and high electrical and thermal conductivity, combined with tunable pore morphology and exceptional mechanical strength and elasticity. This flexible synthetic method can be extended to the fabrication of polymer/carbon nanotube (CNT) and polymer/graphene oxide (GO) composite materials. Furthermore, additional post-synthetic functionalization with anthraquinone is described, which enables a dramatic increase in charge storage performance in supercapacitor applications.

This video method describes the synthesis of high surface area, monolithic 3D graphene-based materials derived from polymer precursors as well as single layer graphene oxide.

합성 및 3D 나노 그래 핀 소재의 기능화 : 그래 핀 에어로젤과 그래 핀 매크로 어셈블리

Efforts to assemble graphene into three-dimensional monolithic structures have been hampered by the high cost and poor processability of graphene. ...

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T.

We describe the methodology of mechanical exfoliation and deposition of flakes of novel materials with micron-sized dimensions onto substrate, fabrication of experimental device structures for transport experimentation, and the magnetotransport measurement in a dry helium close-cycle cryostat at temperatures down to 0.300 K and magnetic fields up to 12 T.

소설 재료의 저온 Magnetotransport 측정을위한 고급 실험 방법

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film ...

Standardized Method for Measuring Collection Efficiency from Wipe-sampling of Trace Explosives

One of the limiting steps to detecting traces of explosives at screening venues is effective collection of the sample. Wipe-sampling is the most common procedure for collecting traces of explosives, and standardized measurements of collection efficiency are needed to evaluate and optimize sampling protocols. The approach described here is designed to provide this measurement infrastructure, and controls most of the factors known to be relevant to wipe-sampling. Three critical factors (the applied force, travel distance, and travel speed) are controlled using an automated device. Test surfaces are chosen based on similarity to the screening environment, and the wipes can be made from any material considered for use in wipe-sampling. Particle samples of the explosive 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) are applied in a fixed location on the surface using a dry-transfer technique. The particle samples, recently developed to simulate residues made after handling explosives, are produced by inkjet printing of RDX solutions onto polytetrafluoroethylene (PTFE) substrates. Collection efficiency is measured by extracting collected explosive from the wipe, and then related to critical sampling factors and the selection of wipe material and test surface. These measurements are meant to guide the development of sampling protocols at screening venues, where speed and throughput are primary considerations.

Optimized sampling protocols and the development of new wipe materials can be facilitated by standardized measurements of collection efficiency from wipe-sampling. Our approach for sampling trace explosives uses an automated device to control speed, force, and distance during wipe-sampling followed by extraction of collected explosives.

추적 폭발물 닦아 샘플링에서 수집 효율을 측정하는 표준화 된 방법

One of the limiting steps to detecting traces of explosives at screening venues is effective collection of the sample. Wipe-sampling is the most common ...

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and forging. Adoption of this technique is proceeding despite disagreement concerning the underlying mechanism responsible for EAD. The experimental procedure described herein enables a more explicit study compared to previous EAD research by removing thermal effects, which are responsible for disagreement in interpreting previous EAD results. Furthermore, as the procedure described here enables EAD observation in situ and in real time in a transmission electron microscope (TEM), it is superior to existing post-mortem methods that observe EAD effects post-test. Test samples consist of a single crystal copper (SCC) foil having a free-standing tensile test section of nanoscale thickness, fabricated using a combination of laser and ion beam milling. The SCC is mounted to an etched silicon base that provides mechanical support and electrical isolation while serving as a heat sink. Using this geometry, even at high current density (~3,500 A/mm2), the test section experiences a negligible temperature increase (&#60;0.02 &#176;C), thus eliminating Joule heating effects. Monitoring material deformation and identifying the corresponding changes to microstructures, e.g. dislocations, are accomplished by acquiring and analyzing a series of TEM images. Our sample preparation and in situ experiment procedures are robust and versatile as they can be readily utilized to test materials with different microstructures, e.g., single and polycrystalline copper.

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Isolating electrical and thermal effects on electrically assisted deformation (EAD) is very difficult using macroscopic samples. Metallic sample micro- and nanostructures together with a custom test procedure have been developed to evaluate the impact of applied current on the formation without joule heating and evolution of dislocations on these samples.

에 대한 소설 방법<em&gt; 현장에서</em&gt; 나노 크기 시편의 전자 기계적 특성 분석

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and ...

A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on high-density data storage and low-power consumption capabilities. However, the high-quality oxide based nonvolatile memory on flexible substrates is often constrained by the material characteristics and the inevitable high-temperature fabrication process. In this paper, a protocol is proposed to directly grow an epitaxial yet flexible lead zirconium titanate memory element on muscovite mica. The versatile deposition technique and measurement method enable the fabrication of flexible yet single-crystalline non-volatile memory elements necessary for the next generation of smart devices.

In this paper, we present a protocol to directly grow an epitaxial yet flexible lead zirconium titanate memory element on muscovite mica.

제조 및 반 데르 발스 Heteroepitaxy에 따라 유연한 Ferroelectric 요소에 대 한 측정 방법

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on ...

Multiscale Structures Aggregated by Imprinted Nanofibers for Functional Surfaces

Multiscale surface structures have attracted increasing interest owing to several potential applications in surface devices. However, an existing challenge in the field is the fabrication of hybrid micro-nano structures using a facile, cost-effective, and high-throughput method. To overcome these challenges, this paper proposes a protocol to fabricate multiscale structures using only an imprint process with an anodic aluminum oxide (AAO) filter and an evaporative self-aggregation process of nanofibers. Unlike previous attempts that have aimed to straighten nanofibers, we demonstrate a unique fabrication method for multiscale aggregated nanofibers with high aspect ratios. Furthermore, the surface morphology and wettability of these structures on various liquids were investigated to facilitate their use in multifunctional surfaces.

Presented is an easy method to fabricate nano-micro multiscale structures, for functional surfaces, by aggregating nanofibers fabricated using an anodic aluminum oxide filter.

기능성 표면에 찍힌된 Nanofibers 여 집계 multiscale 구조

Multiscale surface structures have attracted increasing interest owing to several potential applications in surface devices. However, an existing ...

Studying Large Amplitude Oscillatory Shear Response of Soft Materials

We investigate the sequence of physical processes exhibited during large amplitude oscillatory shearing (LAOS) of polyethylene oxide (PEO) in dimethyl sulfoxide (DMSO) and xanthan gum in water &#8212; two concentrated polymer solutions used as viscosifiers in foods, enhanced oil recovery, and soil remediation. Understanding the nonlinear rheological behavior of soft materials is important in the design and controlled manufacturing of many consumer products. It is shown how the response to LAOS of these polymer solutions can be interpreted in terms of a clear transition from linear viscoelasticity to viscoplastic deformation and back again during a period. The LAOS results are analyzed via the fully quantitative Sequence of Physical Processes (SPP) technique, using free MATLAB-based software. A detailed protocol of performing a LAOS measurement with a commercial rheometer, analyzing nonlinear stress responses with the freeware, and interpreting physical processes under LAOS is presented. It is further shown that, within the SPP framework, a LAOS response contains information regarding the linear viscoelasticity, the transient flow curves, and the critical strain responsible for the onset of nonlinearity.

We present a detailed protocol outlining how to perform nonlinear oscillatory shear rheology on soft materials, and how to run the SPP-LAOS analysis to understand the responses as a sequence of physical processes.

부드러운 재료의 큰 진폭 진동 전단 응답 공부

We investigate the sequence of physical processes exhibited during large amplitude oscillatory shearing (LAOS) of polyethylene oxide (PEO) in dimethyl ...