Name: fabrication of compressed hosiery and measurement of its pressure characteristic exerted on the lower limbs
Uploaded: 2020-05-27T14:00:00
Description: Watch this Scientific Journal Video about Fabrication of Compressed Hosiery and Measurement of its Pressure Characteristic Exerted on the Lower Limbs at JoVE.com

The authors disclose receipt of the following financial support for the research, authorship, and/or publication of this article: National Key R&#38;D Program of China, Grants No. 2018YFC2000900, National Natural Science Foundation of China, Grants No. 11802171, Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, and the Talent Program of Shanghai University of Engineering Science.

1. Fabrication of CH
<ol>
	<li>Programming
	<ol>
		<li>Open the STAT-Ds 615 MP stocking software and select Plain fabric to create a new sock construction.</li>
		<li>Select the following contents in order: Double welt 1 feed, Transfer without pattern, Plain medical leg from double welt 1 feed, Begin heel from plain medical leg, End of heel and plain medical foot, Begin toe from plain foot 1f, ...

<ol>
	<li>Partsch, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+static+stiffness+index:+a+simple+method+to+assess+the+elastic+property+of+vcompression+material+in+vivo.">The static stiffness index: a simple method to assess the elastic property of vcompression material in vivo.</a> Dermatologic Surgery. 31 (6), 625-630 (2010).</li><li>Dissemond, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Compression+therapy+in+patients+with+venous+leg+ulcers.">Compression therapy in patients with venous leg ulcers.</a> Journal der Deutschen Dermatologischen Gesellschaft. 14 (11), 1072-1087 (2016).</li><li>Mosti, G., Picerni, P., Partsch, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Compression+stockings+with+moderate+pressure+are+able+to+reduce+chronic+leg+oedema.">Compression stockings with moderate pressure are able to reduce chronic leg oedema.</a> Phlebology. 27 (6), 289-296 (2012).</li><li>Rabe, E., Partsch, H., Hafner, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Therapy+with+compression+stockings+in+Germany-Results+from+the+Bonn+Vein+Studies.">Therapy with compression stockings in Germany-Results from the Bonn Vein Studies.</a> Journal der Deutschen Dermatologischen Gesellschaft. 11 (3), 257-261 (2013).</li><li>Liu, R., Lao, T. T., Kwok, Y. L., Li, Y., Ying, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+graduated+compression+stockings+with+different+pressure+profiles+on+lower-limb+venous+structures+and+haemodynamics.">Effects of graduated compression stockings with different pressure profiles on lower-limb venous structures and haemodynamics.</a> Advances in Therapy. 25 (5), 465 (2008).</li><li>Bera, M., Chattopadhyay, R., Gupta, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+linear+density+of+elastic+inlay+yarn+on+pressure+generation+on+human+body.">Influence of linear density of elastic inlay yarn on pressure generation on human body.</a> Journal of Industrial Textiles. 46 (4), 1053-1066 (2016).</li><li>Chattopadhyay, R., Gupta, D., Bera, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+input+tension+of+inlay+yarn+on+the+characteristics+of+knitted+circular+stretch+fabrics+and+pressure+generation.">Effect of input tension of inlay yarn on the characteristics of knitted circular stretch fabrics and pressure generation.</a> Journal of Textiles Institute. 103 (6), 636-642 (2012).</li><li>Ozbayraktar, N., Kavusturan, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+inlay+yarn+amount+and+yarn+count+on+extensibility+and+bursting+strength+of+compression+stockings.">The effects of inlay yarn amount and yarn count on extensibility and bursting strength of compression stockings.</a> Tekstil ve Konfeksiyon. 19 (2), 102-107 (2009).</li><li>Maleki, H., Aghajani, M., Sadeghi, A. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+pressure+behavior+of+tubular+weft+knitted+fabrics+constructed+from+textured+polyester+yarns.">On the pressure behavior of tubular weft knitted fabrics constructed from textured polyester yarns.</a> Journal of Engineered Fibers &amp; Fabrics. 6 (2), 30-39 (2011).</li><li>Bera, M., Chattopadhyay, R., Gupta, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+linear+density+of+inlay+yarns+on+structural+characteristics+of+knitted+fabric+tube+and+pressure+generation+on+cylinder.">Effect of linear density of inlay yarns on structural characteristics of knitted fabric tube and pressure generation on cylinder.</a> Journal of Textiles Institute. 106 (1), 39-46 (2015).</li><li>Thomas, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+use+of+the+Laplace+equation+in+the+calculation+of+sub-bandage+pressure.">The use of the Laplace equation in the calculation of sub-bandage pressure.</a> World Wide Wounds. 3 (1), 21-23 (1980).</li><li>Maklewska, E., Nawrocki, A., Ledwo&#324;, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modelling+and+designing+of+knitted+products+used+in+compressive+therapy.">Modelling and designing of knitted products used in compressive therapy.</a> Fibres &amp; Textiles in Eastern Europe. 14 (5), 111-113 (2006).</li><li>Leung, W. Y., Yuen, D. W., Shi, S. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pressure+prediction+model+for+compression+garment+design.">Pressure prediction model for compression garment design.</a> Journal of Burn Care Research. 31 (5), 716-727 (2010).</li><li>Dale, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multilayer+compression:+comparison+of+four+different+four-layer+bandage+systems+applied+to+the+leg.">Multilayer compression: comparison of four different four-layer bandage systems applied to the leg.</a> European Journal of Vascular &amp; Endovascular Surgery. 27 (1), 94-99 (2004).</li><li>Al-Khaburi, J., Nelson, E. A., Hutchinson, J., Dehghani-Sanij, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+multilayered+compression+bandages+on+sub-bandage+pressure:+a+model.">Impact of multilayered compression bandages on sub-bandage pressure: a model.</a> Phlebology. 26 (1), 75-83 (2011).</li><li>Al-Khaburi, J., Dehghani-Sanij, A. A., Nelson, E. A., Hutchinson, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+bandage+thickness+on+interface+pressure+applied+by+compression+bandages.">Effect of bandage thickness on interface pressure applied by compression bandages.</a> Medical Engineering &amp; Physics. 34 (3), 378-385 (2012).</li><li>Sikka, M. P., Ghosh, S., Mukhopadhyay, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mathematical+modeling+to+predict+the+sub-bandage+pressure+on+a+cone+limb+for+multi-layer+bandaging.">Mathematical modeling to predict the sub-bandage pressure on a cone limb for multi-layer bandaging.</a> Medical Engineering &amp; Physics. 38 (9), 917-921 (2016).</li><li>Zhang, L. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+structure+and+pressure+characteristics+of+graduated+compression+stockings:+experimental+and+numerical+study.">The structure and pressure characteristics of graduated compression stockings: experimental and numerical study.</a> Textile Research Journal. 89 (23-24), 5218-5225 (2019).</li></ol>

In this study, we provide two methods to measure the exerted pressure of CH samples and these methods can be used to measure the exerted pressure of other garment dressing on the skin. In the direct method, the CH sample is dressed on the artificial lower limb and the interface sensor is placed under the CH sample. The pressure value can be displayed on the screen using data collection software. To compare with the direct method, we also supply an indirect method. Two theories involving the cylinder model and the cone mo...

Compressed hosiery (CH) provides pressure on the lower limb. It can press the skin and further change the vein radius. Thus, the venous blood flow velocity is raised when the patient is dressed in compressed hosiery. CH and other compressed garments could improve venous circulation in the lower limbs1,2,3,4. The therapeutic performance was dependent on the pressure characteristics of the CH5. It was widely believed that raw material and CH structure have a great influence on CH pressure characteristics. Elastane yarn in CH was primarily responsible for the pressure characteristics according to some published research6. For example, Chattopadhyay7 reported the pressure characteristics of knitted circular stretch fabrics by adjusting the feed tension of elastane yarn. In addition, Ozbayraktar8 also determined that the density of elastane yarn increased while the extensibility of CH decreased. Additionally, loop length9, knitted pattern9, and linear density of the yarns7,10 also exhibited the effects on the pressure characteristics.
A numerical model was presented to inspect the generation mechanism of the pressure characteristics of the CH. Laplace&#8217;s Law was used for predicting the pressure values. Thomas11 introduced Laplace&#8217;s Law into pressure prediction by combining pressure, tension, and body limb size. Similar work also was reported by Maklewska12. To precisely predict the pressure values exerted by the fabric, they presented a semi-empirical equation that was composed of the fitted stress-strain equation and Laplace&#8217;s Law. Additionally, Young&#8217;s modulus was presented by Leung13 to describe elongation of the CH.
The above-mentioned numerical studies showed deviated experimental results due to ignorance of the CH thickness14. In addition, some researchers believed that the hypothetical cylinder involved in Laplace&#8217;s Law was inappropriate to describe the body limbs because the radius of the lower limbs from the thigh to the ankle is not constant but gradually decreases. By combining the thick cylinder theory and Laplace&#8217;s Law, Dale14 and Al Khaburi15,16 respectively proposed numerical models to investigate the pressure exerted by the CH with multiple layers. Sikka17 presented a new cone model with a gradually decreased radius from the thigh to the ankle.
The pressure characteristics intrinsic to CH were difficult to quantitatively study because most of the experimental CHs in previous studies were usually purchased commercially. The influences such as pattern, yarn, raw material were uncontrollable. Therefore, in this study, the experimental CHs were controllably fabricated in house. Moreover, this study aims to provide two methods involving direct method and indirect method to measure the pressure characteristics. In the direct method, an interface sensor (Table of Materials) is placed between the skin and textiles to directly measure the pressure value. On the other hand, in the indirect method, the tension and some structure parameters of the CH sample dressing on the artificial lower limb are firstly measured. Then, the results are substituted into the cone model and the cylinder model to calculate the pressure value. The pressure values obtained as a result of the two methods are contrasted and analyzed to find a more appropriate model. The presented methods provide a guideline to the experimental measurement of pressure exerted by the compressed garment.

<table>
	<tbody>
		<tr>
			<td>Artificial lower limb</td>
			<td>Dayuan, Laizhou Electron Instrument Co., Ltd.</td>
			<td>YG065C</td>
			<td>Used for measuring the strength of stockings. The employing test standard is ISO 13934-1-2013, metioned this in section 3.3</td>
		</tr>
		<tr>
			<td>CH fabrication machine</td>
			<td>Hongda, Co., Ltd.</td>
			<td>YG14N</td>
			<td>Used for measuring the thickness of stockings, the test standard is ISO 5084:1996, metioned this in section 3.2</td>
		</tr>
		<tr>
			<td>Elastane yarn</td>
			<td>MathWorks, Co., Ltd.</td>
			<td>2018a</td>
			<td>Used for calculating the pressure, mentioned this in section 4.</td>
		</tr>
		<tr>
			<td>FlexiForce interface pressure sensors</td>
			<td>Qile, Co., Ltd.</td>
			<td>Y115B</td>
			<td>It is composed of magnifying glass with a fixed ruler. Used for counting the loops number per cm in the fabricated CH, metioned this in the sction 3.1.3 and 3.1.7.</td>
		</tr>
		<tr>
			<td>FlexiForce measurement software</td>
			<td>Santoni, Co., Ltd.</td>
			<td>GOAL 615MP</td>
			<td>Used for fabricating stockings, metioned this in section 1.2</td>
		</tr>
		<tr>
			<td>Ground yarn</td>
			<td>Santoni, Co., Ltd.</td>
			<td></td>
			<td>It is a kind of coverd yarn which is composed of 80% rubber and 20% viscose, metioned this in section 1.2.1</td>
		</tr>
		<tr>
			<td>Matlab software</td>
			<td>Santoni, Co., Ltd.</td>
			<td></td>
			<td>It is a kind of coverd yarn which is composed of 30% polyamide and 70% cotton, metioned this in section 1.2.1</td>
		</tr>
		<tr>
			<td>Mechanical testing instrument and software</td>
			<td>Santoni, Co., Ltd.</td>
			<td>GOAL 615MP</td>
			<td>Used for programing the fabrication parameters, metioned this in section.1.1</td>
		</tr>
		<tr>
			<td>Pick glass</td>
			<td>Shenmei, Inc.</td>
			<td>F002</td>
			<td>A standard artificial femal with 160 cm height. The size was consited with Chinese Standard GB 10000-1988. The artificial femal was made by glass-reinforced plywood and covered by fabric. Mentioned this in section 2.1.</td>
		</tr>
		<tr>
			<td>STAT-Ds 615 MP stocking software</td>
			<td>Tekscan, Inc.</td>
			<td>A201</td>
			<td>Used for measuring the pressure on the skin, metioned this in section 2.2.1</td>
		</tr>
		<tr>
			<td>Thickness gauge</td>
			<td>Weike, Co., Ltd.</td>
			<td>1lbs</td>
			<td>Used for recording the pressure, metioned this in section 2.2.2-2.2.4.</td>
		</tr>
	</tbody>
</table>

fabrication of compressed hosiery and measurement of its pressure characteristic exerted on the lower limbs

This article reports the pressure characteristic measurement of compressed hosiery via direct and indirect methods. In the direct method, an interface sensor is used to measure the pressure value exerted on the lower limbs. In the indirect method, the necessary parameters mentioned by the cone and cylinder model are tested to calculate the pressure value. The necessary parameters involve course density, wales density, circumference, length, thickness, tension, and deformation of the compressed hosiery. Compared with the results of the direct method, the cone model in the indirect method is more suitable for calculating the pressure value because the cone model considers the change in radius of the lower limb from the knee to the ankle. Based on this measurement, the relationship among fabrication, structure, and pressure is further investigated in this study. We find that graduation is the main influence that can change the wales density. On the other hand, elastic motors directly affect the course density and the circumference of the stockings. Our reported work provides the fabrication-structure-pressure relationship and a design guide for gradually compressed hosiery.

Course density gradually increases from the knee to the ankle in Figure 2a. This is explained by the influence of the elastic motor. From the knee to the ankle, the increased elastic motor gradually generates increasing tension from part 5 to part 1 in the CH fabrication process. Thus, the CH sample is gradually frapped and the loop number per cm is increased in the course direction. The experimental lines in Figure 2b can be divided into three groups: ABC, DEF,...

Watch this Scientific Journal Video about Fabrication of Compressed Hosiery and Measurement of its Pressure Characteristic Exerted on the Lower Limbs at JoVE.com

Fabrication of Compressed Hosiery and Measurement of its Pressure Characteristic Exerted on the Lower Limbs

This article reports fabrication, structure and pressure measurement of compressed hosiery by employing direct and indirect methods.

This article reports the pressure characteristic measurement of compressed hosiery via direct and indirect methods. In the direct method, an interface ...

Two different methods are used to measure the prior characteristics of compressed hosiery. As differences exist between the two methods, it is important to quantitatively analyze these differences. The compressed hosiery used for most studies is purchased from the market.The material and structure of these hosieries are uncontrollable. We have fabricated the compressed hosiery samples ourselves. This method could also be used to measure other compression garments, such as compress pants and waistcoats.We're sure demonstration of this method will help viewer to better understand the method and our work. Demonstrating the procedure will be Jiecong Li and Qi Fang, the graduate students from my laboratory. To create a new sock construction, open the Atlas MP615 stocking software and select Plain Fabric.Select DOUBLE WELT 1 FEED, Transfer without pattern, PLAIN MEDICAL LEG FROM DOUBLE WELT 1 FEED, BEGIN HEEL FROM PLAIN MEDICAL LEG, END OF HEEL AND PLAIN MEDICAL FOOT, BEGIN TOE FROM PLAIN FOOT 1F, PLAIN TOE WITH ROSSO AND CLIP, SOCK RELEASE WITHOUT TURNING DEVICE, and END OF SOCK. Then, click OK to complete the sock design. Select 200 for the needle and export the program file onto a USB flash disk.Switch to Quasar to change the fabrication parameters and click any blue button in the GRADUATION row to open a new window. For fabricating the compressed hosiery with a different structure, enter 500 in the Cylinder S and E columns and click OK.Click any one of blue buttons in the ELASTIC MOTORS row and enter 800 in the WELT rows in the Cylinder S and E columns. In the MEDICAL LEG row, enter 800 in the S column and 650 in column E.Then, enter 650 in the ANKLE row in the S and E column and click OK to complete the setup.To prepare the ground and elastane yarns on the compressed hosiery fabrication machine, turn on the machine, insert the USB drive, and select the compressed hosiery fabrication program file. The machine will automatically fabricate the compressed hosiery sample. When all of the samples have been acquired, condition the samples for 24 hours in a standard atmospheric environment.The next day, place a sample onto an artificial lower limb and mark six evenly spaced circle lines on the compressed hosiery sample dressings from the knee to the ankle. These lines divide the compressed hosiery samples into five parts. To perform a pressure measurement, place the interface pressure sensors under part one of the compressed hosiery sample in the anterior, posterior, medial, and lateral directions.Be sure to take care when placing the hosiery onto the artificial leg, as the sensor is very soft and may become folded and damaged during the dressing process. In the measurement software, select the appropriate serial port COM and set the minimum threshold value as zero. Click Start Measurement.A one-to-four real-time channel will display the pressure data. When the pressure is stable, click Stop Measurement. The software will automatically export the pressure data.For structure parameter measurement of the compressed hosiery samples, place a directly measured sample onto the artificial lower limb and use a tape measure to measure the total length of the sample. Use a pick glass to measure the course density and the wales density of each divided part and use the measuring tape to measure the circumference of each circle line. When all of the structure parameter measurements have been acquired, remove the sample from the limb and measure the circumference of each circle line and the course and wales densities of the undressed sample.To acquire a thickness measurement, smooth a compressed hosiery sample onto the steel round table of the thickness gauge and turn on the gauge. Let another steel round slowly fall down to press onto the sample piece. The screen will display the thickness data.To perform a tensile experiment, first cut the compressed hosiery sample along the marked circle lines and clamp one piece of sample into the tensile testing instrument. Next, open the software of the tensile instrument and enter five Newtons as the initial tension, 60 millimeters per minute as the tensile speed, and 200 millimeters as the initial tensile strength. When all of the measurement parameters have been set, click Start.The computer will export the real-time stress and strain on the screen, and the tensile experiment will automatically stop when the compressed hosiery piece is broken. Then, replace the broken piece of sample with a new sample piece for the next round of testing. The course density of the fabricated compressed hosiery sample gradually increases from the knee to the ankle.In the fabrication process, the graduation affects the sinking depth of the needle. Thus, the compressed hosiery samples fabricated with the highest graduation value demonstrate the lowest wales densities and vice versa. The use of an elastic motor has a significant effect on the circumference and cross density of the divided parts, while graduation exerts a significant effect on the wales density.Here, representative pressure data obtained from direct and indirect measurements can be observed. From the ankle to the knee, the exerted pressure magnitude of all of the compressed hosiery samples gradually declined, and it is clear that the cylinder model measurements slightly deviated from the direct measurements, indicating that the predicted pressure data from the cylinder model was inconsistent with the measured pressure. To further quantitatively study the differences between the cone and cylinder models, the Spearman correlation method can be used.For example, in this analysis, the correlation coefficient between the cone model and the measured pressure was higher than the correlation between the cylinder model and the measured pressure, indicating that the cone model is a better model for predicting the pressure characteristic than the cylinder model. The samples should be knitted or woven and acquired not commercially. The pressure can be measured on human skin.The result will differ from those measured for artificial legs, as the former provides a softer surface than the latter. The cone model more accurately than the cylinder model. Therefore, future compression garment pressure measurements should be performed directly on the cone model.

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Synthesis and Microdiffraction at Extreme Pressures and Temperatures

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary interiors, design materials with novel properties, understand the mechanical behavior of materials exposed to very high stresses as in explosions or impacts. Synthesis and structural analysis of materials at extreme conditions of pressure and temperature entails remarkable technical challenges. In the laser heated diamond anvil cell (LH-DAC), very high pressure is generated between the tips of two opposing diamond anvils forced against each other; focused infrared laser beams, shined through the diamonds, allow to reach very high temperatures on samples absorbing the laser radiation. When the LH-DAC is installed in a synchrotron beamline that provides extremely brilliant x-ray radiation, the structure of materials under extreme conditions can be probed in situ. LH-DAC samples, although very small, can show highly variable grain size, phase and chemical composition. In order to obtain the high resolution structural analysis and the most comprehensive characterization of a sample, we collect diffraction data in 2D grids and combine powder, single crystal and multigrain diffraction techniques. Representative results obtained in the synthesis of a new iron oxide, Fe4O5 1 will be shown.

The laser heated diamond anvil cell combined with synchrotron micro-diffraction techniques allows researchers to explore the nature and properties of new phases of matter at extreme pressure and temperature (PT) conditions. Heterogeneous samples can be characterized in situ under high pressure by 2D mapping and combined powder, single-crystal and multigrain diffraction approaches.

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary ...

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Here, we present a protocol to measure, with high spatial resolution, the unsteady surface pressure in turbulent flows. This method demonstrates the construction of a remote microphone probe (RMP) and the determination of its frequency-dependent, complex transfer function. An analytical determination of the dynamic response is presented and validated.

Microphones are widely applied to measure pressure fluctuations at the walls of solid bodies immersed in turbulent flows. Turbulent motions with various ...

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 ...

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A protocol is presented demonstrating a two-step fabrication technique to grow large-sized single-layer rectangular shaped SnSe flakes on low-cost SiO2/Si dielectrics wafers in an atmospheric pressure quartz tube furnace system.

Tin selenide (SnSe) belongs to the family of layered metal chalcogenide materials with a buckled structure like phosphorene, and has shown potential for ...

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. ...

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.

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

Fabrication of Flexible Image Sensor Based on Lateral NIPIN Phototransistors

Flexible photodetectors have been intensely studied for the use of curved image sensors, which are a crucial component in bio-inspired imaging systems, but several challenging points remain, such as a low absorption efficiency due to a thin active layer and low flexibility. We present an advanced method to fabricate a flexible phototransistor array with an improved electrical performance. The outstanding electrical performance is driven by a low dark current owing to deep impurity doping. Stretchable and flexible metal interconnectors simultaneously offer electrical and mechanical stabilities in a highly deformed state. The protocol explicitly describes the fabrication process of the phototransistor using a thin silicon membrane. By measuring I-V characteristics of the completed device in deformed states, we demonstrate that this approach improves the mechanical and electrical stabilities of the phototransistor array. We expect that this approach to a flexible phototransistor can be widely used for the applications of not only next-generation imaging systems/optoelectronics but also wearable devices such as tactile/pressure/temperature sensors and health monitors.

We present a detailed method to fabricate a deformable lateral NIPIN phototransistor array for curved image sensors. The phototransistor array with an open mesh form, which is composed of thin silicon islands and stretchable metal interconnectors, provides flexibility and stretchability. The parameter analyzer characterizes the electrical property of the fabricated phototransistor.

Flexible photodetectors have been intensely studied for the use of curved image sensors, which are a crucial component in bio-inspired imaging systems, ...

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 ...

Fabrication of Surface Acoustic Wave Devices on Lithium Niobate

Manipulation of fluids and particles by acoustic actuation at small scale is aiding the rapid growth of lab-on-a-chip applications. Megahertz-order surface acoustic wave (SAW) devices generate enormous accelerations on their surface, up to 108 m/s2, in turn responsible for many of the observed effects that have come to define acoustofluidics: acoustic streaming and acoustic radiation forces. These effects have been used for particle, cell, and fluid handling at the microscale&#8212;and even at the nanoscale. In this paper we explicitly demonstrate two major fabrication methods of SAW devices on lithium niobate: the details of lift-off and wet etching techniques are described step-by-step. Representative results for the electrode pattern deposited on the substrate as well as the performance of SAW generated on the surface are displayed in detail. Fabrication tricks and troubleshooting are covered as well. This procedure offers a practical protocol for high frequency SAW device fabrication and integration for future microfluidics applications.

Two fabrication techniques, lift-off and wet etching, are described in producing interdigital electrode transducers upon a piezoelectric substrate, lithium niobate, widely used to generate surface acoustic waves now finding broad utility in micro to nanoscale fluidics. The as-produced electrodes are shown to efficiently induce megahertz order Rayleigh surface acoustic waves.&#160;

Manipulation of fluids and particles by acoustic actuation at small scale is aiding the rapid growth of lab-on-a-chip applications. Megahertz-order ...

In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a-VOx

Resistive switching crossbar architecture is highly desired in the field of digital memories due to low cost and high-density benefits. Different materials show variability in resistive switching properties due to the intrinsic nature of the material used, leading to discrepancies in the field because of underlying operation mechanisms. This highlights a need for a reliable technique to understand mechanisms using nanostructural observations. This protocol explains a detailed process and methodology of in&#160;situ nanostructural analysis as a result of electrical biasing using transmission electron microscopy (TEM). It provides visual and reliable evidence of underlying nanostructural changes in real time memory operations. Also included is the methodology of fabrication and electrical characterizations for asymmetric crossbar structures incorporating amorphous vanadium oxide. The protocol explained here for vanadium oxide films can be easily extended to any other materials in a metal-dielectric-metal sandwiched structure. Resistive switching crossbars are predicted to serve the programmable logic and neuromorphic circuits for next-generation memory devices, given the understanding of the operation mechanisms. This protocol reveals the switching mechanism in a reliable, timely, and cost-effective way in any type of resistive switching materials, and thereby predicts the device&#39;s applicability.

In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a-VOx

Presented here is a protocol for analyzing nanostructural changes during in&#160;situ biasing with transmission electron microscopy (TEM) for a stacked metal-insulator-metal structure. It has significant applications in resistive switching crossbars for the next generation of programmable logic circuits and neuromimicking hardware, to reveal their underlying operation mechanisms and practical applicability.