Name: micro/nano-scale strain distribution measurement from sampling moiré fringes
Uploaded: 2017-05-23T15:00:00.000+00:00
Duration: 6 min 56 s
Description: Watch this Scientific Journal Video about Micro/Nano-scale Strain Distribution Measurement from Sampling MoirÃ© Fringes at JoVE.com

这项工作由JSPS KAKENHI，授权号JP16K17988和JP16K05996以及由内阁办公室经营的跨部门战略创新促进计划D66，结构材料创新测量与分析（SIP-IMASM）支持。作者也对Drs感激不尽。 NISSISISISISISHI和Kimiyoshi Naito的CFRP材料。

1.样品上的微/纳米级网格的确认<ol><li> 样品加工 <ol><li>将样品切割成在显微镜下使用的特定加载装置（ 例如， 1×5×30mm 3 ）所需的尺寸，使得观察到的表面比感兴趣区域大1.5倍。 </li><li>对待观察的样品表面进行抛光（ 例如， 1 x 30 mm 2 ），连续在自动抛光机上使用粗细砂纸（ 例如，使用SiC箔＃320 3分钟，然后在800 rpm下＃800进行1分钟和30 N）。每次抛光步骤后，用水清洗样品。 </li><li>抛光相同的样品表面，依次在自动抛光机上使用粗精细抛光溶液（ 例如，使用DP-Spray P 15μm，5 min，P 1μm，8 min，P 0.25μm，150 rpm，10 min; 30 N）。每次抛光后用水清洗样品g步。 </li></ol></li><li> 如果标本上没有定期图案，则制作微/纳米尺度网格 注意:如果样品表面上的微/纳米级上存在天然周期性图案，则可以省略此步骤。从以下选择栅极制造方法:紫外线（UV）或加热纳米压印光刻（NIL） 26 ，电子束光刻（EBL） 2和聚焦离子束（FIB）铣削6 。 注意:这里介绍了网格制作过程，以UV NIL为例。 <ol><li>使用移液管在样品表面上滴2 mL紫外线抗蚀剂。 </li><li>使用旋转涂布机以1500rpm将样品表面上的抗蚀剂涂覆60秒。 </li><li>在0.2MPa的压力下将纳米压印模压制成抗蚀剂层。将抗蚀剂用波长为375nm的UV曝光30秒。 </li><li>将纳米压印模具与样品表面分开。 </li></ol&gt; </li><li> 使用显微镜观察样本上的网格 <ol><li>使用离子涂布机（ 例如， 3Pa的涂覆30秒，溅射电流为30mA）在网格表面上涂覆厚度为3-10nm的铂或金层。 </li><li>将样品置于激光扫描显微镜（LSM） 23下 。 注意:也可以使用其他显微镜，例如透射电子显微镜（TEM） 5 ，原子力显微镜（AFM） 12或扫描电子显微镜（SEM） 7 。 </li><li>通过点击显微镜图像记录软件中的"捕获"和"文件|导出|图像文件"，使用显微镜调整焦点并保存一个网格图像。 </li></ol></li><li> 从网格图像计算样本的网格间距（nm或μm） <ol><li>计算超过10克的平均值在网格图像的中央区域的id间距，以避免扫描或镜头失真的潜在影响。 注意:样品上的网格可以在室温下保存几天。 </li></ol></li></ol> 2.在加载测试中获取网格图像<ol><li> 显微镜下加载试验的准备 <ol><li>在显微镜下将样品固定到加载装置，例如拉伸，压缩，加热或电加载装置。 注意:如果栅格间距小于20 nm，应使用TEM或AFM。如果网格间距为20nm〜10μm，则可以使用SEM。如果网格间距大于400nm，则可以使用LSM。 </li><li>根据具体要求设置负载速度（ 例如， 0.01 mm / s）和负载或位移增量步长（ 例如， 0.5 N /步或0.024 mm /步）。将负载和位移预设为零。 </li><li>使网格冲浪ace在观察平面。通过移动或旋转显微镜的样品台，在低倍率下选择感兴趣的区域。 </li><li>通过使图像中的网格间距大于1.8×1像素大小来选择适当的放大倍率。 注意:通常，最好使图像中的网格间距大于2像素。一个网格间距对应的像素越多，变形测量的精度越高，但测量的视场越小。 </li></ol></li><li> 加载测试中的网格图像集合 <ol><li>通过点击显微镜图像记录软件中的"捕获"和"文件|导出|图像文件"来保存加载区域的网格图像。 </li><li>开始使用加载装置的操作软件，通过施加第一加载步骤（ 例如， 0.5N或0.024mm）将样品原位载入显微镜。 </li><li>录音在显微镜的图像记录软件中单击"捕获"和"文件|导出|图像文件" ，在第一次加载步骤后（ 例如， 0.5 N或0.024 mm）处理感兴趣区域的网格图像。确保显微镜的放大倍数和工作距离保持不变。 </li><li>通过使用装载装置执行每个加载步骤继续加载样品。在每个加载步骤之后记录网格图像，直到样品断裂或直到达到某个值（ 例如，负载19次，并以0.5的间隔以1 N，1.5 N，2.0 N，...，10 N记录19个网格图像N;或0.048mm，0.072mm，0.096mm，...，0.48mm，间隔为0.024mm）。确保显微镜的放大倍数和工作距离保持不变。 注意:网格图像可以任意长时间保存。 </li></ol></li></ol> Def。之前和之后的采样莫尔条纹的生成ormation <ol><li> 网格图像中网格间距（像素）的估计 <ol><li>通过在图像处理软件（ 例如， Microsoft Paint）中测量两个相邻网格点的中心之间的距离，在加载前估算网格图像中的网格间距（单位:像素）。 </li><li>以最大负载估计网格图像中的网格间距。 </li></ol></li><li> 取样间距（像素）的确定 <ol><li>当变形前后的网格间距为1.8至2.5像素时，转到步骤3.2.2。当变形前后的网格间距在2.4和3.6像素之间时跳到步骤3.2.3。当变形前后的网格间距大于3.2像素时跳到步骤3.2.4。 </li><li>将采样间距设置为T = 2像素。跳到步骤3.3。 </li><li>将采样间距设置为T = 3像素。跳到步骤3.3。 </li><li>将采样间距T设置为正整数在0.75x和1.25x之间变形前后的网格间距，由丰富的模拟结果22确定 。 注意:如果有2个正整数满足步骤3.2.1和3.2.4中的要求，最好选择较大的整数作为采样间距。如果有3个或更多的正整数满足要求，最好选择中间整数，只要它比采样间距稍大一点。 </li></ol></li><li> 变形前产生采样莫尔条纹 <ol><li>变形前打开网格图像。假设x方向水平向右， y方向垂直向下，坐标（0,0）位于左上角，计算x方向的图像宽度W和y方向上的图像高度H 。 注意: y方向也可以定义为垂直向上</li><li>转到步骤3.3.3，在y方向产生莫尔条纹。跳到步骤3.3.7在x方向产生莫尔条纹。 </li><li>使用低通滤波器（LPF）将网格图像处理为光栅图像。例如，使用FT算法来抑制光栅，其主方向为x ，其中主方向被定义为垂直于光栅线的方向。将过滤器尺寸设置为接近网格间距。 </li><li>通过仅从几个水平线中提取灰度值，从y = k个像素（ k = 0）（ 图1 ）的采样间距T （T≥2）的间距（ 即仅保持灰色） y = k像素， y = k + T像素，...， y = k + iT像素的采样线中的值，其中i是po坐标整数）。使最后一个采样线的坐标k + iT小于图像高度H。 </li><li>通过用水平采样线执行图像的全场强度插值（线性或B样条），在y方向上生成采样波纹图案。 </li><li>通过在1像素的增量步长处改变k来重复步骤3.3.4和3.3.5 T -1次，从而在y方向上生成其他T -1采样莫尔图案（ 即，将变薄的起始点移动到y = k像素; k = 1，...， T -1）。 </li><li>在步骤3.3.3-3.3.6中使用与步骤3.3.3-3.3.6相同的步骤，通过在步骤3.3.3中将x改变为y来在x方向上生成T阶梯空间相移采样莫尔图案，将图像高度H更改为图像宽度W ，并在步骤3.3中将y更改为x 。4-3.3.6。 注意: x方向上的采样间距可能与y方向不同。 </li></ol></li><li> 变形后产生采样莫尔条纹 <ol><li>在不同的负载下打开所有网格图像。假设网格图像的数量为N。 </li><li>通过重复步骤3.3.3-3.3.6 N次，在y方向生成N组T阶空间相移莫尔条纹。 </li><li>通过重复步骤3.3.7 N次，在x方向生成N组T阶梯空间相移莫尔条纹。 </li></ol></li></ol>加载试验中样品的变形测量<ol><li> 变形前后莫尔条纹强度的确定 <ol><li>在t变形前提取T形波纹条纹的强度他的方向在步骤3.3.5和3.3.6;在步骤3.3.7中确定x方向上的莫尔强度。使用下列公式描述j （ j = x ， y ）方向变形前的T阶（T≥2）莫尔强度: <img alt="公式1" src="/files/ftp_upload/55739/image001.jpg" /> （1） 其中p j是在j （ j = x ， y ）方向变形之前的网格间距， A是调制幅度， D包括背景和较高频率强度。 </li><li>在步骤3.4.2中，在y方向上提取T形台阶莫尔条纹的强度，并在步骤3.4.3中确定x方向上的莫尔强度。描述变形后的T级 （T≥2）莫尔强度通过将I m， j （ k ）， p j ， A和D改变为I &#39;m，j （ k ）， p &#39; ，使用与上述相同的等式（等式1），在j （ j = x ， y ） j ， A &#39;和D &#39;，其中上标单引号意味着变形后。 注意:如果采样间距为T≥3像素，请忽略此步骤，然后跳至步骤4.3。 </li></ol></li><li><ol><li>从变形前的两步采样莫尔强度（ 图1a ）之间的乘积干涉重建多重莫尔条纹，使用以下等式23 <img alt="公式2" src="/files/ftp_upload/55739/image002.jpg" /> （2） 我在哪里， j代表强度of在变形前在j （ j = x ， y ）方向上重构的多重莫尔条纹。 </li><li>使用条纹定心技术24在变形前处理重建的多重莫尔条纹。为连续的整数和半整数f j = [1,1.5,2,2.5，...]分配给重建的叠加莫尔条纹中心线的边界。 注意:如果乘法莫尔条纹太密集，则可以首先确定两步采样莫尔条纹的边界（ 即，f j （ 0）= [1,0，2，0，3，0，...]和f j （1）= [0，1.5，0，2.5，0，3.5，...]）。乘法莫尔条纹的边缘顺序将为f j = f j （0）+ f j （1）= [1,1.5,2,2.5,3,3.5，...]。刚体位移不会影响应变结果。 </li><li>使用以下等式23测量变形前样品相对于采样间距的相对应变 <img alt="公式3" src="/files/ftp_upload/55739/image003.jpg" /> （3） <img alt="公式4" src="/files/ftp_upload/55739/image004.jpg" /> （4） 其中u j _rela和εj _rela分别表示在j （ j = x ， y ）方向变形之前样品的相对位移和相对应变，γxy _rela表示变形前的相对剪切应变。 </li><li>重复步骤4.2.1-4.2.3确定样品在x和y方向变形后的相对应变N次，改变I multi， j ， I m， j （0）， I m， j </在方程（2） - （4）中，对于I&#39;multi ， j ， I &#39;，（1）， p （ j ），（ j ）， j ， j ， m， j （0）， I &#39;m， j （1）， p&#39;j ， A &#39;， D &#39;， u&#39;j _rela （j = x，y）， ε&#39;j _rela和γ&#39;xy _上标单引号表示变形后。 </li><li>确定j （ j = x ， y ）方向上的实际正应变εj，其是网格间距和剪切应变的相对变化，γxy，这是绝对值e由变形前后相对应变载荷引起的试样网格角变化20 。 <img alt="公式5" src="/files/ftp_upload/55739/image005.jpg" /> （5） <img alt="方程式6" src="/files/ftp_upload/55739/image006.jpg" /> （6） </li></ol></li><li> 采样间距为T≥3像素时的变形测量 <ol><li>使用空间相移技术计算k = 0时变形前的j （ j = x ， y ）方向上的采样莫尔条纹的相位（ 图1b ） 21 <img alt="公式7" src="/files/ftp_upload/55739/image007.jpg" /> （7） </li><li>当k = 0时，通过代替φm获得变形后的j （ j = x ， y ）方向上的采样莫尔条纹的相位， <em&gt; j和I m， j （ k ）在等式（7）中分别为φ&#39;m ， j和I &#39;m， j （ k ），其中上标单引号表示变形后。对N个负载重复N次。 注意:如果在步骤4.3.1和4.3.2中的相位分​​布中存在太多的随机噪声，则可以使用sin / cos滤波器25来平滑相位。 </li><li>确定变形前后的j （ j = x ， y ）方向上的采样莫尔条纹的相位差（ 即 Δφm ， j =φ&#39;m ， j - φm ， j ）。 </li><li>测量位移u j ，正应变εj的分布<em&gt; j（ j = x ， y ）方向，由载荷引起的试样的剪切应变γxy。使用以下等式6,21 <img alt="公式8" src="/files/ftp_upload/55739/image008.jpg" /> （8） <img alt="公式9" src="/files/ftp_upload/55739/image009.jpg" /> （9） <img alt="方程式10" src="/files/ftp_upload/55739/image010.jpg" /> （10） 注意:如果应变分布中的噪声太大，可以使用平均滤光片，滤光片尺寸小于2个网格间距。 </li></ol></li><li> 结果存储 <ol><li>保存莫尔条纹，相位（采样间距为T≥3像素）的数据，图像形式的位移和应变，如.tif或.bmp文件和文本，如.txt或.csv文件。 </li></ol></li></ol>

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Lasers Eng. 48 (11), 1067-1075 (2010).</li><li>Li, Y., Xie, H., Chen, P., Zhang, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Theoretical+analysis+of+moir&#233;+fringe+multiplication+under+a+scanning+electron+microscope.">Theoretical analysis of moir&#233; fringe multiplication under a scanning electron microscope.</a> Meas. Sci. Technol. 22 (2), 025301 (2010).</li><li>Patorski, K., Wielgus, M., Ekielski, M., Ka&#378;mierczak, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=AFM+nanomoir&#233;+technique+with+phase+multiplication.">AFM nanomoir&#233; technique with phase multiplication.</a> Meas. Sci. Technol. 24 (3), 035402 (2013).</li><li>Wang, Q., Ri, S., Takashita, Y., Ogihara, S., Yoshida, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+33:+Full-field+measurements+of+principal+strains+and+orientations+using+moir&#233;+fringes.">Chapter 33: Full-field measurements of principal strains and orientations using moir&#233; fringes.</a> Advancement of Optical Methods in Experimental Mechanics. 3, 251-259 (2017).</li><li>Wang, Z., Han, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advanced+iterative+algorithm+for+phase+extraction+of+randomly+phase-shifted+interferograms.">Advanced iterative algorithm for phase extraction of randomly phase-shifted interferograms.</a> Opt. Lett. 29 (14), 1671-1673 (2004).</li><li>Wang, Q., Xie, H., Hu, Z., Zhang, J., Sun, J., Liu, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Residual+thermo-creep+deformation+of+copper+interconnects+by+phase-shifting+SEM+moir&#233;+method.">Residual thermo-creep deformation of copper interconnects by phase-shifting SEM moir&#233; method.</a> Appl. Mech. Mater. 83, 185-190 (2011).</li><li>Ri, S., Fujigaki, M., Morimoto, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sampling+moir&#233;+method+for+accurate+small+deformation+distribution+measurement.">Sampling moir&#233; method for accurate small deformation distribution measurement.</a> Exp. Mech. 50 (4), 501-508 (2010).</li><li>Ri, S., Muramatsu, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Theoretical+error+analysis+of+the+sampling+moir&#233;+method+and+phase+compensation+methodology+for+single-shot+phase+analysis.">Theoretical error analysis of the sampling moir&#233; method and phase compensation methodology for single-shot phase analysis.</a> Appl. 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Opt. 55 (25), 6858-6865 (2016).</li><li>Dai, F., Wang, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automatic+fringe+patterns+analysis+using+digital+processing+tehniques:+I+fringe+center+method.">Automatic fringe patterns analysis using digital processing tehniques: I fringe center method.</a> Acta Photonica Sinica. 28, 700-706 (1999).</li><li>Gutmann, B., Weber, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phase-shifter+calibration+and+error+detection+in+phase-shifting+applications:+a+new+method.">Phase-shifter calibration and error detection in phase-shifting applications: a new method.</a> Appl. 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作者没有什么可以披露的。

在所描述的技术中，如果样品上没有周期性图案，则一个具有挑战性的步骤是微/纳米尺度网格或光栅（缩写为格栅）制造26 。变形前网格间距应均匀，因为它是变形测量的重要参数。如果材料是金属，金属合金或陶瓷，UV或加热纳米压印光刻（NIL） 27 ，电子束光刻（EBL） 2 ，聚焦离子束（FIB）铣削6或网格重复法<sup class="xref"...

微/纳米尺度变形测量对于评估先进材料的机械性能，不稳定行为，残余应力和裂纹发生至关重要。由于光学技术是非接触的，全场的和非破坏性的，所以已经开发了用于近几十年的变形测量​​的各种光学方法。近年来，微纳米尺度变形测量技术主要包括莫尔方法1,2,3,4 ，几何相位分析（GPA） 5,6 ，傅里叶变换（FT），数字图像相关（DIC）和电子散斑图案干涉测量（ESPI）。在这些技术中，由于存在多个频率，所以GPA和FT不太适用于复杂的变形测量​​。 DIC方法是sim因为变形载体是随机斑点，而是无噪声。最后，ESPI对振动非常敏感。 在微/纳米级莫尔方法中，目前最常用的方法是显微镜扫描莫尔法，例如电子扫描莫尔7,8,9 ，激光扫描莫尔10,11和原子力显微镜（AFM）莫尔12 ，以及一些基于显微镜的莫尔方法，例如数字/重叠莫尔13,14,15方法和乘法/分数莫尔法16,17 。扫描莫尔法具有广泛的视野，高分辨率等诸多优点并且对随机噪声不敏感。然而，传统的扫描莫尔法对于2D应变测量是不方便的，因为需要将样品台或扫描方向旋转90°并扫描两次以在两个方向18上产生莫尔条纹。旋转和双重扫描过程引入旋转误差并花费很长时间，严重影响2D应变的测量精度，特别是对于剪切应变。虽然时间相移技术19,20可以提高变形测量精度，但是它需要时间和特殊的相移装置不适于动态测试。 采样莫尔法21,22在位移测量中具有高精度，并且现在主要用于当汽车p屁股。为了将采样莫尔法扩展到微尺度/纳米尺度的2D应变测量，从2像素采样莫尔条纹开始，新开发了一种重新构成的多重波纹法，其中测量是灵敏度的两倍，保持扫描波纹法。此外，空间相移采样莫尔法也是从多像素采样莫尔条纹开发的，允许进行高精度应变测量。该协议将介绍详细的应变测量程序，并有望帮助研究人员和工程师学习如何测量变形，改进材料和产品的制造过程。

<table><tbody><tr><td>Automatic Polishing Machine</td><td>Marumoto Struers K.K.</td><td>LaboPol-30, Labor Force-100</td><td></td></tr><tr><td>Carbon Fiber Reinforced Plastic</td><td>Mitsubishi Plastics, Inc.&amp;nbsp;</td><td>HYEJ16M95DHX1</td><td></td></tr><tr><td>Computer</td><td>DELL Japan</td><td>VOSTRO</td><td>Can be replaced with another computer with C++ programming language</td></tr><tr><td>Image Recording Software</td><td>Lasertec Corporation</td><td>LMEYE7</td><td>Installed in a laser scanning microscope</td></tr><tr><td>Ion Coater</td><td>Japan Electron Optics Laboratory Ltd.</td><td>JEC3000F</td><td></td></tr><tr><td>Laser Scanning Microscope</td><td>Lasertec Corporation</td><td>OPTELICS HYBRID</td><td></td></tr><tr><td>Nanoimprint Device</td><td>Japan Laser Corporation&amp;nbsp;</td><td>EUN-4200</td><td>Can be replaced with a electron beam lithography device or a focused ion beam milling device</td></tr><tr><td>Nanoimprint Mold</td><td>SCIVAX Corporation</td><td>3.0&amp;mu;m pitch</td><td>Customized</td></tr><tr><td>Nanoimprint Resist</td><td>Toyo Gosei Co., Ltd&amp;nbsp;</td><td>PAK01</td><td></td></tr><tr><td>Polishing Solution</td><td>Marumoto Struers K.K.</td><td>DP-Spray P 15&amp;mu;m, 1&amp;mu;m, 0.25&amp;mu;m</td><td>Use from coarse to fine</td></tr><tr><td>Pipet</td><td>AS ONE Corporation</td><td>10mL</td><td></td></tr><tr><td>Sand Paper</td><td>Marumoto Struers K.K.</td><td>SiC Foil #320, #800</td><td>Use from coarse to fine</td></tr><tr><td>Spin Coater</td><td>MIKASA Corporation</td><td>MS-A100</td><td></td></tr></tbody></table>

micro/nano-scale strain distribution measurement from sampling moir&#233; fringes

这项工作描述了全场微/纳米尺度变形测量的采样莫尔技术的测量程序和原理。开发的技术可以通过两种方式进行:使用重建的多重莫尔法或空间相移采样莫尔法。当样本网格间距约为2像素时，产生2像素采样莫尔条纹以重建用于变形测量的乘法云纹图案。位移和应变灵敏度都是在同一广视野范围内的传统扫描波纹法的两倍。当样本网格间距大于或大于3像素时，产生多像素采样莫尔条纹，并组合空间相移技术进行全场变形测量。应变测量精度得到显着提高，并且易于实现自动批量测量。两种方法都可以像传统的莫尔技术一样，测量来自单点格栅图像的二维（2D）应变分布，而不旋转样品或扫描线。作为示例，在三点弯曲试验中测量了二维位移和应变分布，包括两个碳纤维增强塑料样品的剪切应变。所提出的技术预计将在各种材料的机械性能，裂纹发生和残余应力的非破坏性定量评估中发挥重要作用。

根据莫尔形成原理23和测量过程（ 图1 ）测量两种碳纤维增强塑料（CFRP）样品（＃1和＃2）的二维位移和应变分布。 CFRP样品由10-11μm直径的K13D碳纤维和环氧树脂制成。使用来自两步采样莫尔条纹的重建的叠加莫尔法确定CFRP＃1的变形，并且使用来自三步采样莫尔条纹的空间相移采样莫尔法测量CFRP＃2的变形。 <p class="jove_step" fo:kee...

Watch this Scientific Journal Video about Micro/Nano-scale Strain Distribution Measurement from Sampling MoirÃ© Fringes at JoVE.com

Micro/Nano-scale Strain Distribution Measurement from Sampling Moir&#233; Fringes

这里介绍了采用2像素和多像素采样方法进行微/纳米级高精度应变分布测量的采样莫尔技术。

微米/纳米尺度应变分布测量从采样莫尔条纹

This work describes the measurement procedure and principles of a sampling moir&#233; technique for full-field micro/nano-scale deformation measurements. ...

micronano-scale-strain-distribution-measurement-from-sampling-moir

Universidad San Sebastian

Research

JoVE Journal

Engineering

12.2K 次观看.  National Institute of Advanced Industrial Science and Technology (AIST). 这里介绍了采用2像素和多像素采样方法进行微/纳米级高精度应变分布测量的采样莫尔技术。 

视频: Micro/Nano-scale Strain Distribution Measurement from Sampling Moiré Fringes

Measuring Material Microstructure Under Flow Using 1-2 Plane Flow-Small Angle Neutron Scattering

A new small-angle neutron scattering (SANS) sample environment optimized for studying the microstructure of complex fluids under simple shear flow is presented. The SANS shear cell consists of a concentric cylinder Couette geometry that is sealed and rotating about a horizontal axis so that the vorticity direction of the flow field is aligned with the neutron beam enabling scattering from the 1-2 plane of shear (velocity-velocity gradient, respectively). This approach is an advance over previous shear cell sample environments as there is a strong coupling between the bulk rheology and microstructural features in the 1-2 plane of shear. Flow-instabilities, such as shear banding, can also be studied by spatially resolved measurements. This is accomplished in this sample environment by using a narrow aperture for the neutron beam and scanning along the velocity gradient direction. Time resolved experiments, such as flow start-ups and large amplitude oscillatory shear flow are also possible by synchronization of the shear motion and time-resolved detection of scattered neutrons. Representative results using the methods outlined here demonstrate the useful nature of spatial resolution for measuring the microstructure of a wormlike micelle solution that exhibits shear banding, a phenomenon that can only be investigated by resolving the structure along the velocity gradient direction. Finally, potential improvements to the current design are discussed along with suggestions for supplementary experiments as motivation for future experiments on a broad range of complex fluids in a variety of shear motions.

A shear cell is developed for small-angle neutron scattering measurements in the velocity-velocity gradient plane of shear and is used to characterize complex fluids. Spatially resolved measurements in the velocity gradient direction are possible for studying shear-banding materials. Applications include investigations of colloidal dispersions, polymer solutions, and self-assembled structures.

测量材料在微流使用1-2面流小角中子散射

A new small-angle neutron scattering (SANS) sample environment optimized for studying the microstructure of complex fluids under simple shear flow is ...

科研

工程学

Implementation of a Reference Interferometer for Nanodetection

A thermally and mechanically stabilized fiber interferometer suited for examining ultra-high quality factor microcavities is fashioned. After assessing its free spectral range (FSR), the module is put in parallel with a fiber taper-microcavity system and then calibrated through isolating and eliminating random shifts in the laser frequency (i.e. laser jitter noise). To realize the taper-microcavity junction and to maximize the optical power that is transferred to the resonator, a single-mode optical fiber waveguide is pulled. Solutions containing polystyrene nanobeads are then prepared and flown to the microcavity in order to demonstrate the system&#8217;s ability to sense binding to the surface of the microcavity. Data is post-processed via adaptive curve fitting, which allows for high-resolution measurements of the quality factor as well as the plotting of time-dependent parameters, such as resonant wavelength and split frequency shifts. By carefully inspecting steps in the time-domain response and shifting in the frequency-domain response, this instrument can quantify discrete binding events.

A reference interferometer technique, which is designed to remove undesirable laser jitter noise for nanodetection, is utilized for probing an ultra-high quality factor microcavity. Instructions for assembly, setup, and data acquisition are provided, alongside the measurement process for specifying the cavity quality factor.

一个参考干涉仪的Nanodetection实施

A thermally and mechanically stabilized fiber interferometer suited for examining ultra-high quality factor microcavities is fashioned. After assessing ...

Stress Distribution During Cold Compression of Rocks and Mineral Aggregates Using Synchrotron-based X-Ray Diffraction

We report detailed procedures for performing compression experiments on rocks and mineral aggregates within a multi-anvil deformation apparatus (D-DIA) coupled with synchrotron X-radiation. A cube-shaped sample assembly is prepared and compressed, at room temperature, by a set of four X-ray transparent sintered diamond anvils and two tungsten carbide anvils, in the lateral and the vertical planes, respectively. All six anvils are housed within a 250-ton hydraulic press and driven inward simultaneously by two wedged guide blocks. A horizontal energy dispersive X-ray beam is projected through and diffracted by the sample assembly. The beam is commonly in the mode of either white or monochromatic X-ray. In the case of white X-ray, the diffracted X-rays are detected by a solid-state detector array that collects the resulting energy dispersive diffraction pattern. In the case of monochromatic X-ray, the diffracted pattern is recorded using a two-dimensional (2-D) detector, such as an imaging plate or a charge-coupled device (CCD) detector. The 2-D diffraction patterns are analyzed to derive lattice spacings. The elastic strains of the sample are derived from the atomic lattice spacing within grains. The stress is then calculated using the predetermined elastic modulus and the elastic strain. Furthermore, the stress distribution in two-dimensions allow for understanding how stress is distributed in different orientations. In addition, a scintillator in the X-ray path yields a visible light image of the sample environment, which allows for the precise measurement of sample length changes during the experiment, yielding a direct measurement of volume strain on the sample. This type of experiment can quantify the stress distribution within geomaterials, which can ultimately shed light on the mechanism responsible for compaction. Such knowledge has the potential to significantly improve our understanding of key processes in rock mechanics, geotechnical engineering, mineral physics, and material science applications where compactive processes are important.

We report detailed procedures for compression experiments on rocks and mineral aggregates within a multi-anvil deformation apparatus coupled with synchrotron X-radiation. Such experiments allow quantification of the stress distribution within samples, that ultimately sheds light on compaction processes in geomaterials.

基于同步辐射 x 射线衍射的岩石和矿物团聚体冷压缩应力分布

We report detailed procedures for performing compression experiments on rocks and mineral aggregates within a multi-anvil deformation apparatus (D-DIA) ...

环境科学

Observing and Quantifying Fibroblast-mediated Fibrin Gel Compaction

Cells embedded in collagen and fibrin gels attach and exert traction forces on the fibers of the gel. These forces can lead to local and global reorganization and realignment of the gel microstructure. This process proceeds in a complex manner that is dependent in part on the interplay between the location of the cells, the geometry of the gel, and the mechanical constraints on the gel. To better understand how these variables produce global fiber alignment patterns, we use time-lapse differential interference contrast (DIC) microscopy coupled with an environmentally controlled bioreactor to observe the compaction process between geometrically spaced explants (clusters of fibroblasts). The images are then analyzed with a custom image processing algorithm to obtain maps of the strain. The information obtained from this technique can be used to probe the mechanobiology of various cell-matrix interactions, which has important implications for understanding processes in wound healing, disease development, and tissue engineering applications.

Time-lapse microscopy and image processing techniques were used to observe and analyze fibroblast-mediated gel compaction and fibrin fiber realignment in an environmentally controlled bioreactor over a 48 hr&#160;period.

观察和量化纤维细胞介导的纤维素凝胶压实

Cells embedded in collagen and fibrin gels attach and exert traction forces on the fibers of the gel. These forces can lead to local and global ...

生物工程

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder microdiffraction two-dimensional (2D) maps at beamline 12.3.2 of the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory. Measurements can be performed on any sample that is less than 10 cm x 10 cm x 5 cm, with a flat exposed surface. The experimental geometry is calibrated using standard materials (elemental standards for XRF, and crystalline samples such as Si, quartz, or Al2O3 for diffraction). Samples are aligned to the focal point of the x-ray microbeam, and raster scans are performed, where each pixel of a map corresponds to one measurement, e.g., one XRF spectrum or one diffraction pattern. The data are then processed using the in-house developed software XMAS, which outputs text files, where each row corresponds to a pixel position. Representative data from moissanite and an olive snail shell are presented to demonstrate data quality, collection, and analysis strategies.

We describe a beamline setup meant to carry out rapid two-dimensional x-ray fluorescence and x-ray microdiffraction mapping of single crystal or powder samples using either Laue (polychromatic radiation) or powder (monochromatic radiation) diffraction. The resulting maps give information about strain, orientation, phase distribution, and plastic deformation.

矿物和岩石样品的同步辐射 x 射线 Microdiffraction 和荧光成像

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder ...

Full-field Strain Measurements for Microstructurally Small Fatigue Crack Propagation Using Digital Image Correlation Method

A novel measurement approach is used to reveal the cumulative deformation field at a sub-grain level and to study the influence of microstructure on the growth of microstructurally small fatigue cracks. The proposed strain field analysis methodology is based on the use of a unique pattering technique with a characteristic speckle size of approximately 10 &#181;m. The developed methodology is applied to study the small fatigue crack behavior in body centered cubic (bcc) Fe-Cr ferritic stainless steel with a relatively large grain size allowing a high spatial measurement accuracy at the sub-grain level. This methodology allows the measurement of small fatigue crack growth retardation events and associated intermittent shear strain localization zones ahead of the crack tip. In addition, this can be correlated with the grain orientation and size. Thus, the developed methodology can provide a deeper fundamental understanding of the small fatigue crack growth behavior, required for the development of robust theoretical models for the small fatigue crack&#160;propagation in polycrystalline materials.

Microstructurally small fatigue crack growth behavior is investigated using a novel methodological approach combining crack growth rate measurement and strain-field analysis to reveal the cumulative deformation field at sub-grain level.

基于数字图像相关的微结构小疲劳裂纹扩展的全场应变测量

A novel measurement approach is used to reveal the cumulative deformation field at a sub-grain level and to study the influence of microstructure on the ...

Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures

Photonic crystals are periodic nanostructures that can support a variety of confined electromagnetic modes. Such confined modes are usually accompanied by local enhancement of electric field intensity that strengthens light-matter interactions, enabling applications such as surface-enhanced Raman scattering (SERS) and surface plasmon enhanced sensing. In the presence of magneto-optically active materials, the local field enhancement gives rise to anomalous magneto-optical activity. Typically, the confined modes of a given photonic crystal depend strongly on the wavelength and incidence angle of the incident electromagnetic radiation. Thus, spectral and angular-resolved measurements are needed to fully identify them as well as to establish their relationship with the magneto-optical activity of the crystal. In this article, we describe how to use a Fourier-plane (back focal plane) microscope to characterize magneto-optically active samples. As a model system, here we use a plasmonic grating built out of magneto-optically active Au/Co/Au multilayer. In the experiments, we apply a magnetic field on the grating in situ and measure its reciprocal space response, obtaining the magneto-optical response of the grating over a range of wavelengths and incident angles. This information enables us to build a complete map of the plasmonic band structure of the grating and the angle and wavelength dependent magneto-optical activity. These two images allow us to pinpoint the effect that the plasmon resonances have on the magneto-optical response of the grating. The relatively small magnitude of magneto-optical effects requires a careful treatment of the acquired optical signals. To this end, an image processing protocol for obtaining magneto-optical response from the acquired raw data is laid out.

Photonic band structure enables understanding how confined electromagnetic modes propagate within a photonic crystal. In photonic crystals that incorporate magnetic elements, such confined and resonant optical modes are accompanied by enhanced and modified magneto-optical activity. We describe a measurement procedure to extract the magneto-optical band structure by Fourier space microscopy.

光子纳米结构的光谱和角度解析磁-光学特性

Photonic crystals are periodic nanostructures that can support a variety of confined electromagnetic modes. Such confined modes are usually accompanied by ...

Production of a Strain-Measuring Device with an Improved 3D Printer

A traditional strain measurement sensor needs to be electrified and is susceptible to electromagnetic interference. In order to solve the fluctuations in the analog electrical signal in a traditional strain gauge operation, a new strain measurement method is presented here. It uses a photographic technique to display the strain change by amplifying the change of the pointer displacement of the mechanism. A visual polydimethylsiloxane (PDMS) lens with a focal length of 7.16 mm was added to a smartphone camera to generate a lens group acting as a microscope to capture images. It had an equivalent focal length of 5.74 mm. Acrylonitrile butadiene styrene (ABS) and nylon amplifiers were used to test the influence of different materials on the sensor performance. The production of the amplifiers and PDMS lens is based on improved 3D printing technology. The data obtained were compared with the results from finite element analysis (FEA) to verify their validity. The sensitivity of the ABS amplifier was 36.03 &plusmn; 1.34 &#181;&epsilon;/&#181;m, and the sensitivity of the nylon amplifier was 36.55 &plusmn; 0.53 &#181;&epsilon;/&#181;m.

This work presents a strain measurement sensor consisting of an amplification mechanism and a polydimethylsiloxane microscope manufactured using an improved 3D printer.

使用改进的 3D 打印机生产应变测量设备

A traditional strain measurement sensor needs to be electrified and is susceptible to electromagnetic interference. In order to solve the fluctuations in ...

Microtensiometer for Confocal Microscopy Visualization of Dynamic Interfaces

Adsorption of surface-active molecules to fluid-fluid interfaces is ubiquitous in nature. Characterizing these interfaces requires measuring surfactant adsorption rates, evaluating equilibrium surface tensions as a function of bulk surfactant concentration, and relating how surface tension changes with changes in the interfacial area following equilibration. Simultaneous visualization of the interface using fluorescence imaging with a high-speed confocal microscope allows the direct evaluation of structure-function relationships. In the capillary pressure microtensiometer (CPM), a hemispherical air bubble is pinned at the end of the capillary in a 1 mL volume liquid reservoir. The capillary pressure across the bubble interface is controlled via a commercial microfluidic flow controller that allows for model-based pressure, bubble curvature, or bubble area control based on the Laplace equation. Compared to previous techniques such as the Langmuir trough and pendant drop, the measurement and control precision and response time are greatly enhanced; capillary pressure variations can be applied and controlled in milliseconds. The dynamic response of the bubble interface is visualized via a second optical lens as the bubble expands and contracts. The bubble contour is fit to a circular profile to determine the bubble curvature radius, R, as well as any deviations from circularity that would invalidate the results. The Laplace equation is used to determine the dynamic surface tension of the interface. Following equilibration, small pressure oscillations can be imposed by the computer-controlled microfluidic pump to oscillate the bubble radius (frequencies of 0.001-100 cycles/min) to determine the dilatational modulus The overall dimensions of the system are sufficiently small that the microtensiometer fits under the lens of a high-speed confocal microscope allowing fluorescently tagged chemical species to be quantitatively tracked with submicron lateral resolution.

This manuscript describes the design and operation of a microtensiometer/confocal microscope to do simultaneous measurements of interfacial tension and surface dilatational rheology while visualizing the interfacial morphology. This provides the real-time construction of structure-property relationships of interfaces important in technology and physiology.

用于动态界面共聚焦显微镜可视化的微量天体测量仪

Adsorption of surface-active molecules to fluid-fluid interfaces is ubiquitous in nature. Characterizing these interfaces requires measuring surfactant ...

Controlled Strain of 3D Hydrogels under Live Microscopy Imaging

External forces are an important factor in tissue formation, development, and maintenance. The effects of these forces are often studied using specialized in vitro stretching methods. Various available systems use 2D substrate-based stretchers, while the accessibility of 3D techniques to strain soft hydrogels, is more restricted. Here, we describe a method that allows external stretching of soft hydrogels from their circumference, using an elastic silicone strip as the sample carrier. The stretching system utilized in this protocol is constructed from 3D-printed parts and low-cost electronics, making it simple and easy to replicate in other labs. The experimental process begins with polymerizing thick (&#62;100 &#956;m) soft fibrin hydrogels (Elastic Modulus of ~100 Pa) in a cut-out at the center of a silicone strip. Silicone-gel constructs are then attached to the printed-stretching device and placed on the confocal microscope stage. Under live microscopy the stretching device is activated, and the gels are imaged at various stretch magnitudes. Image processing is then used to quantify the resulting gel deformations, demonstrating relatively homogenous strains and fiber alignment throughout the gel&#8217;s 3D thickness (Z-axis). Advantages of this method include the ability to strain extremely soft hydrogels in 3D while executing in situ microscopy, and the freedom to manipulate the geometry and size of the sample according to the user&#8217;s needs. Additionally, with proper adaptation, this method can be used to stretch other types of hydrogels (e.g., collagen, polyacrylamide or polyethylene glycol) and can allow for analysis of cells and tissue response to external forces under more biomimetic 3D conditions.

The presented method involves uniaxial stretching of 3D soft hydrogels embedded in silicone rubber while allowing live confocal microscopy. Characterization of the external and internal hydrogel strains as well as fiber alignment are demonstrated. The device and protocol developed can assess the response of cells to various strain regimes.

实时显微镜成像下的 3D 水凝胶控制应变

External forces are an important factor in tissue formation, development, and maintenance. The effects of these forces are often studied using specialized ...