Name: micro/nano-scale strain distribution measurement from sampling moir&#233; fringes
Uploaded: 2017-05-23T15:00:00
Description: Watch this Scientific Journal Video about Micro/Nano-scale Strain Distribution Measurement from Sampling MoirÃ© Fringes at JoVE.com

This work was supported by JSPS KAKENHI, grant numbers JP16K17988 and JP16K05996, and by the Cross-Ministerial Strategic Innovation Promotion Program, Unit D66, Innovative Measurement and Analysis for Structural Materials (SIP-IMASM), operated by the cabinet office. The authors are also grateful to Drs. Satoshi Kishimoto and Kimiyoshi Naito at NIMS for their CFRP material.

1. Confirmation of the Micro/Nano-scale Grid on the Specimen
<ol>
	<li>Machining of the Specimen
	<ol>
		<li>Cut the specimen to the size required by the specific loading device used under a microscope (e.g., 1 x 5 x 30 mm3), making the surface to be observed 1.5x greater than the region of interest.</li>
		<li>Polish the specimen surface to be observed (e.g., 1 x 30 mm2), successively using coarse and fine sand paper on an automatic polishing machine (e.g., ...

<ol>
	<li>Weller, R., Shepard, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Displacement+measurement+by+mechanical+interferometry.">Displacement measurement by mechanical interferometry.</a> Proc. Soc. Exp. Stress Anal. 6 (1), 35-38 (1948).</li><li>Kishimoto, S., Egashira, M., Shinya, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microcreep+deformation+measurements+by+a+moir&#233;+method+using+electron+beam+lithography+and+electron+beam+scan.">Microcreep deformation measurements by a moir&#233; method using electron beam lithography and electron beam scan.</a> Opt. Eng. 32 (3), 522-526 (1993).</li><li>Ifju, P., 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=Recent+applications+of+moir&#233;+interferometry.">Recent applications of moir&#233; interferometry.</a> Exp. Mech. 50 (8), 1129-1147 (2010).</li><li>Zhang, H., Wu, C., Liu, Z., Xie, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+curved+surface+micro-moir&#233;+method+and+its+application+in+evaluating+curved+surface+residual+stress.">A curved surface micro-moir&#233; method and its application in evaluating curved surface residual stress.</a> Meas. Sci. Technol. 25 (9), 095002 (2014).</li><li>Zhang, H., Liu, Z., Wen, H., Xie, H., Liu, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subset+geometric+phase+analysis+method+for+deformation+evaluation+of+HRTEM+images.">Subset geometric phase analysis method for deformation evaluation of HRTEM images.</a> Ultramicroscopy. 171, 34-42 (2016).</li><li>Wang, Q., Kishimoto, S., Xie, H., Liu, Z., Lou, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+high+temperature+creep+deformation+of+micro-structure+with+metal+film+wire+on+flexible+membrane+using+geometric+phase+analysis.">In situ high temperature creep deformation of micro-structure with metal film wire on flexible membrane using geometric phase analysis.</a> Microelectron. Reliab. 53 (4), 652-657 (2013).</li><li>Wang, Q., Kishimoto, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+analysis+of+residual+stress+and+stress+intensity+factor+in+a+resist+after+UV-nanoimprint+lithography+based+on+electron+moir&#233;+fringes.">Simultaneous analysis of residual stress and stress intensity factor in a resist after UV-nanoimprint lithography based on electron moir&#233; fringes.</a> J. Micromech. Microeng. 22 (10), 105021 (2012).</li><li>Kishimoto, S., Wang, Q., Xie, H., Zhao, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Study+of+the+surface+structure+of+butterfly+wings+using+the+scanning+electron+microscopic+moir&#233;+method.">Study of the surface structure of butterfly wings using the scanning electron microscopic moir&#233; method.</a> Appl. Opt. 46 (28), 7026-7034 (2007).</li><li>Li, C., Liu, Z., Xie, H., Wu, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+3D+SEM+Moir&#233;+method+for+micro+height+measurement.">Novel 3D SEM Moir&#233; method for micro height measurement.</a> Opt. Express. 21 (13), 15734-15746 (2013).</li><li>Xie, H., Wang, Q., Kishimoto, S., Dai, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+planar+periodic+structure+using+inverse+laser+scanning+confocal+microscopy+moir&#233;+method+and+its+application+in+the+structure+of+butterfly+wing.">Characterization of planar periodic structure using inverse laser scanning confocal microscopy moir&#233; method and its application in the structure of butterfly wing.</a> J. Appl. Phys. 101 (10), 103511 (2007).</li><li>Tang, M., Xie, H., Wang, Q., Zhu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phase-shifting+laser+scanning+confocal+microscopy+moir&#233;+method+and+its+applications.">Phase-shifting laser scanning confocal microscopy moir&#233; method and its applications.</a> Meas. Sci. Technol. 21 (5), 055110 (2010).</li><li>Xie, H., Kishimoto, S., Asundi, A., Boay, C. G., Shinya, N., Yu, J., Ngoi, B. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In-plane+deformation+measurement+using+the+atomic+force+microscope+moir&#233;+method.">In-plane deformation measurement using the atomic force microscope moir&#233; method.</a> Nanotechnology. 11 (1), 24 (2000).</li><li>Xie, H., Liu, Z., Fang, D., Dai, F., Gao, H., Zhao, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+study+on+the+digital+nano-moir&#233;+method+and+its+phase+shifting+technique.">A study on the digital nano-moir&#233; method and its phase shifting technique.</a> Meas. Sci. Technol. 15 (9), 1716 (2004).</li><li>Wang, Q., Kishimoto, S., Yamauchi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-directional+structural+characterization+of+hexagonal+packed+nanoparticles+by+hexagonal+digital+moir&#233;+method.">Three-directional structural characterization of hexagonal packed nanoparticles by hexagonal digital moir&#233; method.</a> Opt. Lett. 37 (4), 548-550 (2012).</li><li>Liu, Z., Lou, X., Gao, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deformation+analysis+of+MEMS+structures+by+modified+digital+moir&#233;+methods.">Deformation analysis of MEMS structures by modified digital moir&#233; methods.</a> Opt. 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. Opt. 51 (16), 3214-3223 (2012).</li><li>Wang, Q., Ri, S., Tsuda, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Digital+sampling+Moir&#233;+as+a+substitute+for+microscope+scanning+Moir&#233;+for+high-sensitivity+and+full-field+deformation+measurement+at+micron/nano+scales.">Digital sampling Moir&#233; as a substitute for microscope scanning Moir&#233; for high-sensitivity and full-field deformation measurement at micron/nano scales.</a> Appl. 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. Opt. 37 (32), 7624-7631 (1998).</li><li>Wang, Q., Kishimoto, S., Tanaka, Y., Kagawa, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micro/submicro+grating+fabrication+on+metals+for+deformation+measurement+based+on+ultraviolet+nanoimprint+lithography.">Micro/submicro grating fabrication on metals for deformation measurement based on ultraviolet nanoimprint lithography.</a> Opt. Lasers Eng. 51 (7), 944-948 (2013).</li><li>Min-Jin, T., Hui-Min, X., Yan-Jie, L., Xiao-Jun, L., Dan, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+grating+fabrication+technique+on+metal+films+using+UV-nanoimprint+lithography.">A new grating fabrication technique on metal films using UV-nanoimprint lithography.</a> Chin. Phys. Lett. 29 (9), 098101 (2012).</li></ol>

In the described technique, one challenging step is the micro/nano-scale grid or grating (abbreviated as grid) fabrication26 if no periodic pattern exists on the specimen. The grid pitch should be uniform before deformation because it is an important parameter for the deformation measurement. If the material is a metal, a metal alloy, or a ceramic, UV or heating nanoimprint lithography (NIL)27, electron beam lithography (EBL)2, focused ion beam (FIB)...

Micro/nano-scale deformation measurements are vitally essential for evaluating the mechanical properties, instability behaviors, residual stresses, and crack occurrences of advanced materials. Since optical techniques are non-contact, full-field, and non-destructive, various optical methods have been developed for deformation measurement during the last few decades. In recent years, the micro/nano-scale deformation measurement techniques mainly include the moir&#233; methods1,2,3,4, geometric phase analysis (GPA)5,6, Fourier transformation (FT), digital image correlation (DIC), and electronic speckle pattern interferometry (ESPI). Among these techniques, GPA and FT are not well suited for complex deformation measurements because multiple frequencies exist. The DIC method is simple but powerless against noise because the deformation carrier is random speckle. Finally, ESPI is strongly sensitive to vibration.
Among micro/nano-scale moir&#233; methods, the most commonly used methods at present are the microscope scanning moir&#233; methods, such as electron scanning moir&#233;7,8,9, laser scanning moir&#233;10,11, and atomic force microscope (AFM) moir&#233;12, and some microscope-based moir&#233; methods, such as the digital/overlapping moir&#233;13,14,15 method and the multiplication/fractional moir&#233; method16,17. The scanning moir&#233; method has many advantages, such as a wide field of view, high resolution, and insensitivity to random noise. However, the traditional scanning moir&#233; method is inconvenient for 2D strain measurements because it is necessary to rotate the sample stage or the scanning direction by 90&#176; and to scan twice to generate moir&#233; fringes in two directions18. Rotation and the dual scanning processes introduce rotation error and take a long time, seriously influencing the measurement accuracy of the 2D strain, especially for the shear strain. Although the temporal phase-shifting technique19,20 can improve the deformation measurement accuracy, it requires time and a special phase-shift device unsuitable for dynamic tests.
The sampling moir&#233; method21,22 has a high accuracy in displacement measurements and is now mainly used for deflection measurements on bridges when automobiles pass. To extend the sampling moir&#233; method to micro/nano-scale 2D strain measurements, a reconstructed multiplication moir&#233; method has been newly developed23 from 2-pixel sampling moir&#233; fringes, in which the measurements are twice as sensitive and the wide field of view of the scanning moir&#233; method is kept. Moreover, the spatial phase-shifting sampling moir&#233; method is also developed from multi-pixel sampling moir&#233; fringes, allowing for high-accuracy strain measurements. This protocol will introduce the detailed strain measurement procedure and is expected to help researchers and engineers learn how to measure deformation, improving the manufacturing processes of materials and products.

<table border="0" cellpadding="0" cellspacing="0" width="737">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:208px;">Automatic Polishing Machine</td>
			<td style="width:161px;">Marumoto Struers K.K.</td>
			<td style="width:201px;">LaboPol-30, Labor Force-100</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="34">
			<td height="34" style="height:34px;width:208px;">Carbon Fiber Reinforced Plastic</td>
			<td style="width:161px;">Mitsubishi Plastics, Inc.&#160;</td>
			<td style="width:201px;">HYEJ16M95DHX1</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="85">
			<td height="85" style="height:85px;width:208px;">Computer</td>
			<td style="width:161px;">DELL Japan</td>
			<td style="width:201px;">VOSTRO</td>
			<td style="width:167px;">Can be replaced with another computer with C++ programming language</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:208px;">Image Recording Software</td>
			<td style="width:161px;">Lasertec Corporation</td>
			<td style="width:201px;">LMEYE7</td>
			<td style="width:167px;">Installed in a laser scanning microscope</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:208px;">Ion Coater</td>
			<td style="width:161px;">Japan Electron Optics Laboratory Ltd.</td>
			<td style="width:201px;">JEC3000F</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:208px;">Laser Scanning Microscope</td>
			<td style="width:161px;">Lasertec Corporation</td>
			<td style="width:201px;">OPTELICS HYBRID</td>
			<td></td>
		</tr>
		<tr height="90">
			<td height="90" style="height:90px;width:208px;">Nanoimprint Device</td>
			<td style="width:161px;">Japan Laser Corporation&#160;</td>
			<td style="width:201px;">EUN-4200</td>
			<td style="width:167px;">Can be replaced with a electron beam lithography device or a focused ion beam milling device</td>
		</tr>
		<tr height="90">
			<td height="90" style="height:90px;width:208px;">Nanoimprint Mold</td>
			<td style="width:161px;">SCIVAX Corporation</td>
			<td style="width:201px;">3.0&#956;m pitch</td>
			<td style="width:167px;">Customized</td>
		</tr>
		<tr height="90">
			<td height="90" style="height:90px;width:208px;">Nanoimprint Resist</td>
			<td style="width:161px;">Toyo Gosei Co., Ltd&#160;</td>
			<td style="width:201px;">PAK01</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:208px;">Polishing Solution</td>
			<td style="width:161px;">Marumoto Struers K.K.</td>
			<td style="width:201px;">DP-Spray P 15&#956;m, 1&#956;m, 0.25&#956;m</td>
			<td>Use from coarse to fine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:208px;">Pipet</td>
			<td style="width:161px;">AS ONE Corporation</td>
			<td style="width:201px;">10mL</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:208px;">Sand Paper</td>
			<td style="width:161px;">Marumoto Struers K.K.</td>
			<td style="width:201px;">SiC Foil #320, #800</td>
			<td>Use from coarse to fine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:208px;">Spin Coater</td>
			<td>MIKASA Corporation</td>
			<td style="width:201px;">MS-A100</td>
			<td></td>
		</tr>
	</tbody>
</table>

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

This work describes the measurement procedure and principles of a sampling moir&#233; technique for full-field micro/nano-scale deformation measurements. The developed technique can be performed in two ways: using the reconstructed multiplication moir&#233; method or the spatial phase-shifting sampling moir&#233; method. When the specimen grid pitch is around 2 pixels, 2-pixel sampling moir&#233; fringes are generated to reconstruct a multiplication moir&#233; pattern for a deformation measurement. Both the displacement and strain sensitivities are twice as high as in the traditional scanning moir&#233; method in the same wide field of view. When the specimen grid pitch is around or greater than 3 pixels, multi-pixel sampling moir&#233; fringes are generated, and a spatial phase-shifting technique is combined for a full-field deformation measurement. The strain measurement accuracy is significantly improved, and automatic batch measurement is easily achievable. Both methods can measure the two-dimensional (2D) strain distributions from a single-shot grid image without rotating the specimen or scanning lines, as in traditional moir&#233; techniques. As examples, the 2D displacement and strain distributions, including the shear strains of two carbon fiber-reinforced plastic specimens, were measured in three-point bending tests. The proposed technique is expected to play an important role in the non-destructive quantitative evaluations of mechanical properties, crack occurrences, and residual stresses of a variety of materials.

The 2D displacement and strain distributions of two carbon fiber-reinforced plastic (CFRP) specimens (#1 and #2) were measured according to the moir&#233; formation principle23 and the measurement process (Figure 1). The CFRP specimens were made up of 10-11 &#181;m-diameter K13D carbon fibers and epoxy resins. The deformation of CFRP #1 was determined using the reconstructed multiplication moir&#233; method from two-step sampling moir&...

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&amp;#233; Fringes

A sampling moir&#233; technique featuring 2-pixel and multi-pixel sampling methods for high-accuracy strain distribution measurements at the micro/nano-scale is presented here.

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

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

The overall goal of this experiment is to accurately measure the strain distributions of materials at the micro or nano scale using the two-pixel or multi-pixel sampling moir

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

Research

JoVE Journal

Engineering

Measurement of Scattering Nonlinearities from a Single Plasmonic Nanoparticle

Plasmonics, which are based on the collective oscillation of electrons due to light excitation, involve strongly enhanced local electric fields and thus have potential applications in nonlinear optics, which requires extraordinary optical intensity. One of the most studied nonlinearities in plasmonics is nonlinear absorption, including saturation and reverse saturation behaviors. Although scattering and absorption in nanoparticles are closely correlated by the Mie theory, there has been no report of nonlinearities in plasmonic scattering until very recently. 
Last year, not only saturation, but also reverse saturation of scattering in an isolated plasmonic particle was demonstrated for the first time. The results showed that saturable scattering exhibits clear wavelength dependence, which seems to be directly linked to the localized surface plasmon resonance (LSPR). Combined with the intensity-dependent measurements, the results suggest the possibility of a common mechanism underlying the nonlinear behaviors of scattering and absorption. These nonlinearities of scattering from a single gold nanosphere (GNS) are widely applicable, including in super-resolution microscopy and optical switches. 
In this paper, it is described in detail how to measure nonlinearity of scattering in a single GNP and how to employ the super-resolution technique to enhance the optical imaging resolution based on saturable scattering. This discovery features the first super-resolution microscopy based on nonlinear scattering, which is a novel non-bleaching contrast method that can achieve a resolution as low as l/8 and will potentially be useful in biomedicine and material studies.

Saturable and reverse saturable scattering were discovered in isolated plasmonic particles and adopted as a novel non-bleaching contrast method in super-resolution microscopy. Here the experimental procedures of detecting and extracting nonlinear scattering are explained in detail, as well as how to enhance resolution with the aid of saturated excitation microscopy.

Plasmonics, which are based on the collective oscillation of electrons due to light excitation, involve strongly enhanced local electric fields and thus ...

Strain Sensing Based on Multiscale Composite Materials Reinforced with Graphene Nanoplatelets

The electrical response of NH2-functionalized graphene nanoplatelets composite materials under strain was studied. Two different manufacturing methods are proposed to create the electrical network in this work: (a) the incorporation of the nanoplatelets into the epoxy matrix and (b) the coating of the glass fabric with a sizing filled with the same nanoplatelets. Both types of multiscale composite materials, with an in-plane electrical conductivity of ~10-3 S/m, showed an exponential growth of the electrical resistance as the strain increases due to distancing between adjacent functionalized graphene nanoplatelets and contact loss between overlying ones. The sensitivity of the materials analyzed during this research, using the described procedures, has been shown to be higher than commercially available strain gauges. The proposed procedures for self-sensing of the structural composite material would facilitate the structural health monitoring of components in difficult to access emplacements such as offshore wind power farms. Although the sensitivity of the multiscale composite materials was considerably higher than the sensitivity of metallic foils used as strain gauges, the value reached with NH2 functionalized graphene nanoplatelets coated fabrics was nearly an order of magnitude superior. This result elucidated their potential to be used as smart fabrics to monitor human movements such as bending of fingers or knees. By using the proposed method, the smart fabric could immediately detect the bending and recover instantly. This fact permits precise monitoring of the time of bending as well as the degree of bending.

The integration of conductive nanoparticles, such as graphene nanoplatelets, into glass fiber composite materials creates an intrinsic electrical network susceptible to strain. Here, different methods to obtain strain sensors based on the addition of graphene nanoplatelets into the epoxy matrix or as a coating on glass fabrics are proposed.

The electrical response of NH2-functionalized graphene nanoplatelets composite materials under strain was studied. Two different manufacturing methods are ...

Optical Trap Loading of Dielectric Microparticles In Air

We demonstrate a method to trap a selected dielectric microparticle in air using radiation pressure from a single-beam gradient optical trap. Randomly scattered dielectric microparticles adhered to a glass substrate are momentarily detached using ultrasonic vibrations generated by a piezoelectric transducer (PZT). Then, the optical beam focused on a selected particle lifts it up to the optical trap while the vibrationally excited microparticles fall back to the substrate. A particle may be trapped at the nominal focus of the trapping beam or at a position above the focus (referred to here as the levitation position) where gravity provides the restoring force. After the measurement, the trapped particle can be placed at a desired position on the substrate in a controlled manner. 
In this protocol, an experimental procedure for selective optical trap loading in air is outlined. First, the experimental setup is briefly introduced. Second, the design and fabrication of a PZT holder and a sample enclosure are illustrated in detail. The optical trap loading of a selected microparticle is then demonstrated with step-by-step instructions including sample preparation, launching into the trap, and use of electrostatic force to excite particle motion in the trap and measure charge. Finally, we present recorded particle trajectories of Brownian and ballistic motions of a trapped microparticle in air. These trajectories can be used to measure stiffness or to verify optical alignment through time domain and frequency domain analysis. Selective trap loading enables optical tweezers to track a particle and its changes over repeated trap loadings in a reversible manner, thereby enabling studies of particle-surface interaction.

A protocol for launching and stably trapping selected dielectric microparticles in air is presented.

We demonstrate a method to trap a selected dielectric microparticle in air using radiation pressure from a single-beam gradient optical trap. Randomly ...

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.

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 ...

Generation of Size-controlled Poly (ethylene Glycol) Diacrylate Droplets via Semi-3-Dimensional Flow Focusing Microfluidic Devices

Uniform and size-controllable poly (ethylene glycol) diacrylate (PEGDA) droplets could be produced via the flow focusing process in a microfluidic device. This paper proposes a semi-three-dimensional (semi-3D) flow-focusing microfluidic chip for droplet formation. The polydimethylsiloxane (PDMS) chip was fabricated using the multi-layer soft lithography method. Hexadecane containing surfactant was used as the continuous phase, and PEGDA with the ultraviolet (UV) photo-initiator was the dispersed phase. Surfactants allowed the local surface tension to drop and formed a more cusped tip which promoted breaking into tiny micro-droplets. As the pressure of dispersed phase was constant, the size of droplets became smaller with increasing continuous phase pressure before dispersed phase flow was broken off. As a result, droplets with size variation from 1 &#181;m to 80 &#181;m in diameter could be selectively achieved by changing the pressure ratio in two inlet channels, and the average coefficient of variation was estimated to be below 7%. Furthermore, droplets could turn into micro-beads by UV exposure for photo-polymerization. Conjugating biomolecules on such micro-beads surface have many potential applications in the fields of biology and chemistry.

Generation of Size-controlled Poly ethylene Glycol Diacrylate Droplets via Semi-3-Dimensional Flow Focusing Microfluidic Devices

Here, we present a protocol to illustrate the fabrication processes and verifying experiments of a semi-three-dimensional (semi-3D) flow-focusing microfluidic chip for droplet formation.

Uniform and size-controllable poly (ethylene glycol) diacrylate (PEGDA) droplets could be produced via the flow focusing process in a microfluidic device. ...

Cutting Procedures, Tensile Testing, and Ageing of Flexible Unidirectional Composite Laminates

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, where the yarns in each layer are oriented parallel to each other and held in place using binder resins and thin polymer films. The armor is constructed by stacking the unidirectional layers in different orientations. To date, only very preliminary work has been performed to characterize the ageing of the binder resins used in unidirectional laminates and the effects on their performance. For example, during the development of the conditioning protocol used in the National Institute of Justice Standard-0101.06, UD laminates showed visual signs of delamination and reductions in V50, which is the velocity at which half of the projectiles are expected to perforate the armor, after ageing. A better understanding of the material property changes in UD laminates is necessary to comprehend the long-term performance of armors constructed from these materials. There are no current standards recommended for mechanically interrogating unidirectional (UD) laminate materials. This study explores methods and best practices for accurately testing the mechanical properties of these materials and proposes a new test methodology for these materials. Best practices for ageing these materials are also described.

The goal of the study was to develop protocols to prepare consistent specimens for accurate mechanical testing of high-strength aramid or ultra-high-molar-mass polyethylene-based flexible unidirectional composite laminate materials and to describe protocols for performing artificial ageing on these materials.

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, ...

Intermediate Strain Rate Material Characterization with Digital Image Correlation

The mechanical response of a material under dynamic load is typically different than its behavior under static conditions; therefore, the common quasistatic equipment and procedures used for material characterization are not applicable for materials under dynamic loads. The dynamic response of a material depends on its deformation rate and is broadly categorized into high (i.e., greater than 200/s), intermediate (i.e., 10&#8722;200/s) and low strain rate regimes (i.e., below 10/s). Each of these regimes calls for specific facilities and testing protocols to ensure the reliability of the acquired data. Due to the limited access to high-speed servo-hydraulic facilities and validated testing protocols, there is a noticeable gap in the results at the intermediate strain rate. The current manuscript presents a validated protocol for the characterization of different materials at these intermediate strain rates. Strain gauge instrumentation and digital image correlation protocols are also included as complimentary modules to extract the utmost level of detailed data from every single test. Examples of raw data, obtained from a variety of materials and test setups (e.g., tensile and shear) is presented and the analysis procedure used to process the output data is described. Finally, the challenges of dynamic characterization using the current protocol, along with the limitations of the facility and methods of overcoming potential problems are discussed.

Here we present a methodology for the dynamic characterization of tensile specimens at intermediate strain rates using a high-speed servo-hydraulic load frame. Procedures for strain gauge instrumentation and analysis, as well as for digital image correlation strain measurements on the specimens, are also defined.

The mechanical response of a material under dynamic load is typically different than its behavior under static conditions; therefore, the common ...

Method Development for Contactless Resonant Cavity Dielectric Spectroscopic Studies of Cellulosic Paper

The current analytical techniques for characterizing printing and graphic arts substrates are largely ex situ and destructive. This limits the amount of data that can be obtained from an individual sample and renders it difficult to produce statistically relevant data for unique and rare materials. Resonant cavity dielectric spectroscopy is a non-destructive, contactless technique which can simultaneously interrogate both sides of a sheeted material and provide measurements which are suitable for statistical interpretations. This offers analysts the ability to quickly discriminate between sheeted materials based on composition and storage history. In this methodology article, we demonstrate how contactless resonant cavity dielectric spectroscopy may be used to differentiate between paper analytes of varying fiber species compositions, to determine the relative age of the paper, and to detect and quantify the amount of post-consumer waste (PCW) recycled fiber content in manufactured office paper.

A protocol for the non-destructive analysis of the fiber content and relative age of paper.

The current analytical techniques for characterizing printing and graphic arts substrates are largely ex situ and destructive. This limits the amount of ...

Measuring Sub-23 Nanometer Real Driving Particle Number Emissions Using the Portable DownToTen Sampling System

The current particle size threshold of the European Particle Number (PN) emission standards is 23 nm. This threshold could change because future combustion engine vehicle technology may emit large amounts of sub-23 nm particles. The Horizon 2020 funded project DownToTen (DTT) developed a sampling and measurement method to characterize particle emissions in this currently unregulated size range. A PN measurement system was developed based on an extensive review of the literature and laboratory experiments testing a variety of PN measurement and sampling approaches. The measurement system developed is characterized by high particle penetration and versatility, which enables the assessment of primary particles, delayed primary particles, and secondary aerosols, starting from a few nanometers in diameter. This paper provides instruction on how to install and operate this Portable Emission Measurement System (PEMS) for Real Drive Emissions (RDE) measurements and assess particle number emissions below the current legislative limit of 23 nm.

Presented here is the DownToTen (DTT) portable emission measurement system to assess real driving automotive emissions of sub-23 nm particles.

The current particle size threshold of the European Particle Number (PN) emission standards is 23 nm. This threshold could change because future ...

Calibration Procedures for Orthogonal Superposition Rheology

Orthogonal superposition (OSP) rheology is an advanced rheological technique that involves superimposing a small-amplitude oscillatory shear deformation orthogonal to a primary shear flow. This technique allows the measurement of structural dynamics of complex fluids under non-linear flow conditions, which is important for the understanding and prediction of the performance of a wide range of complex fluids. The OSP rheological technique has a long history of development since the 1960s, mainly through the custom-built devices that highlighted the power of this technique. The OSP technique is now commercially available to the rheology community. Given the complicated design of the OSP geometry and the non-ideal flow field, users should understand the magnitude and sources of measurement error. This study presents calibration procedures using Newtonian fluids that includes recommendations for best practices to reduce measurement errors. Specifically, detailed information on the end-effect factor determination method, sample filling procedure, and identification of the appropriate measurement range (e.g., shear rate, frequency, etc.) are provided.

We present a detailed calibration protocol for a commercial orthogonal superposition rheology technique using Newtonian fluids including end-effect correction factor determination methods and recommendations for best practices to reduce experimental error.

Orthogonal superposition (OSP) rheology is an advanced rheological technique that involves superimposing a small-amplitude oscillatory shear deformation ...