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, Plain toe with rosso and clip, Sock release without turning device, and End of sock. Press OK button to complete the sock design.</li>
		<li>Select 200 for the Needle and export the program file onto a USB flash disk.</li>
		<li>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 CH with different structure, enter 500 in the Cylinder S and E columns and click OK to complete the setup.</li>
		<li>Click any one of blue buttons in the ELASTIC MOTORS row to open a new window and enter 800 in the WELT rows and 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 and the S and E column and click OK to complete the setup.</li>
		<li>Repeat steps 1.1.4 and 1.1.5. Respectively enter 350 and 650 when adjusting GRADUATION. Respectively enter 1000 and 1200 in the WELT row, and keep the ANKLE row as 650 when adjusting ELASTIC MOTORS. 
		NOTE: The elastic motors could control the tension of the elastane yarn. Fabricated CH should ensure that the tightness gradually increased from knee to ankle. Here, the elastic motor number in the ANKLE is fixed (650), while the elastic motor number in the WELT is changed (800, 1000, 1200) to fabricate CH samples with different tightness. The graduation could control the loop size of the whole CH sample. Larger loops usually result in looser CH, while smaller loops always generate a tight CH sample. Thus, we respectively input 350, 500, and 650 as the graduation. Finally, program files with altered elastic motors and graduation are generated.</li>
	</ol>
	</li>
	<li>Knitting
	<ol>
		<li>Prepare the ground yarn and elastane yarn on the CH fabrication machine.</li>
		<li>Turn on the machine, insert the USB flash disk, and select the program file obtained from step 1.1.3. The machine will automatically fabricates the CH sample. Alphabetically number these samples from A to I. 
		NOTE: Table 1 displays the fabrication parameters of these CH samples.</li>
	</ol>
	</li>
</ol>
2. Direct measurement
NOTE: All of the CH samples should be conditioned for 24 h in standard atmospheric environment (23 &#176;C, 65% relative humidity [RH]) prior to measurement. The CH samples are dressed on the artificial lower limb to test the pressure value. All measurements should be performed three times to calculate the average value and decrease the error.
<ol>
	<li>Mark the lines on the CH sample.
	<ol>
		<li>Place a sample onto an artificial lower limb.</li>
		<li>Mark six, evenly spaced, circle lines on the compressed hosiery sample dressings from the knee to the ankle. Number these lines as line 6, 5, 4.... These lines divide the CH sample into five parts, as shown in Figure 1a.</li>
	</ol>
	</li>
	<li>Pressure measurement
	<ol>
		<li>To perform a pressure measurement, place the interface pressure sensors under part 1 of the compressed hosiery sample in the anterior, posterior, medial, and lateral directions.</li>
		<li>In the measurement software, select the appropriate serial port COM and set the minimum threshold value as 0.</li>
		<li>Click Start Measurement. Real-time channel 1~4 will display the pressure data</li>
		<li>When the pressure is stable, click Stop Measurement. The software will automatically export the pressure data.</li>
		<li>Place the interface press sensors under other parts of CH sample and repeat steps 2.2.1&#8722;2.2.4.</li>
	</ol>
	</li>
	<li>After pressure measurement of the whole CH sample, remove the CH sample and then dress another CH sample on the artificial lower limb to prepare for the next measurement.</li>
</ol>
3. Indirect measurement
NOTE: The experiments here measure the necessary parameters of the cone and cylinder model. These parameters contain the deformation and structure parameters of the dressing and undressed CH samples, thickness, tension. All the CH samples should be conditioned for 24 h in standard atmospheric environment (23 &#176;C, 65% RH) prior to measurement. All measurements should be performed three times to calculate the average value and decrease the error.
<ol>
	<li>Structure parameter measurement of CH samples
	<ol>
		<li>Place a CH sample on the&#160;artificial lower limb.</li>
		<li>Use a measuring tape to measure the total length (L) of the sample.</li>
		<li>Use a pick glass to measure the course density and the Wales density of each divided part.</li>
		<li>Measure the circumference (c) of each circle line with measuring tape. Then, calculate the circumference (w) of each divided part of the CH sample by averaging the circumferences (c) of the neighboring circle lines.</li>
		<li>When all of the structure parameter measurements have been acquired, remove the sample from the limb. And then dress another sample on the artificial lower limb to prepare for next measurement.</li>
		<li>Measure the circumference (c&#8217;) of each circle line of an undressed CH sample. Then, calculate the circumference (w&#8217;) of each divided part of CH sample by averaging the circumferences of the neighboring circle lines.</li>
		<li>Measure the course density and the wales density of the same divided part of the undressed CH sample.</li>
	</ol>
	</li>
	<li>Thickness measurement
	<ol>
		<li>Smooth a compressed hosiery sample onto the steel round table of the thickness gauge.</li>
		<li>Turn on the thickness gauge to let another steel round slowly fall down to&#160;press onto&#160;the sample piece. The screen will display&#160;the thickness data (t).</li>
		<li>Move the sample and repeat steps 3.2.1 and 3.2.2 to test the thickness of other parts.</li>
	</ol>
	</li>
	<li>Tensile experiment
	<ol>
		<li>Cut all the CH samples along the marked circle lines.</li>
		<li>Clamp one piece of sample into the tensile testing instrument.</li>
		<li>Open the software for tensile experiment, input 5 N as the initial tension, 60 mm/,min&#160;as the tensile speed, and 200 mm as the initial tensile length. Keep the default setup for the other fields.</li>
		<li>When all of the measurement parameters have been set, click START to run tensile experiment automatically. The computer will export real-time stress and strain on the screen. The tensile experiment will automatically stop when the CH piece is broken.</li>
		<li>Then replace the broken piece of sample with a new sample piece for the next round of testing and repeat steps 3.3.3&#8722;3.3.4.</li>
	</ol>
	</li>
</ol>
4. Theoretical calculation
NOTE: The cylinder model and cone model are employed in the indirect measurement to calculate the exerted pressure. Each CH sample is separated into five parts from the knee to the ankle. In the cylinder model, human limbs are described as a cylinder with a constant radius while the radius of the limb is variable in the cone model. The schematic diagrams are illustrated in Figure 1b and Figure 1c. All calculation steps are performed in Matlab 2018a and the calculation program can be found in the Supplemental Coding File.
<ol>
	<li>Cylinder model
	<ol>
		<li>According to the measured results obtained from step 3.1.3&#8722;3.1.5, calculate the circumference difference (D) between the dressed CH and the undressed CH using the following equation: 
		<img alt="Equation 1" src="/files/ftp_upload/60852/60852equ01.jpg" /> 
		where i is the number of CH piece that is separated by marked circle lines. It is numbered according to the circle line number.</li>
		<li>Fit the stress-strain curve obtained in step 3.3.4 using an appropriate linear equation. The slope of the linear equation is the tensile modulus E.</li>
		<li>Calculate the tension in the dressing CH (T) by employing the equation: 
		<img alt="Equation 2" src="/files/ftp_upload/60852/60852equ02.jpg" /> 
		NOTE: Supplemental Table 1 displays the obtained original tensile modulus E and tension T.</li>
		<li>Based on the cylinder model and the thin wall assumption15, express the exerted pressure of CH piece i as: 
		<img alt="Equation 3" src="/files/ftp_upload/60852/60852equ03.jpg" /> 
		where r is the radius of divided part and equals to <img alt="Equation 5" src="/files/ftp_upload/60852/60852equ05.jpg" />, t is the thickness of CH sample, and T is the tension calculated from step 4.1.3.</li>
		<li>Calculate all the exerted pressure of CH pieces following steps 4.1.1&#8722;4.1.4.</li>
	</ol>
	</li>
	<li>Cone model
	<ol>
		<li>Calculate the exerted pressure of the CH piece i by the following equation14: 
		<img alt="Equation 4" src="/files/ftp_upload/60852/60852equ04.jpg" /> 
		where rc is the radius of circle line and equals to <img alt="Equation 6" src="/files/ftp_upload/60852/60852equ06.jpg" />, T is the tension calculated from step 4.1.3, l is the length of each divided piece and can be calculated by l = L/5 (herein, L is measured following step 3.1.2).</li>
	</ol>
	</li>
</ol>

<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>

The authors have nothing to disclose.

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,...

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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 ...

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2.2K Views.  Shanghai University of Engineering Science. This article reports fabrication, structure and pressure measurement of compressed hosiery by employing direct and indirect methods.

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

Patterning via Optical Saturable Transitions - Fabrication and Characterization

This protocol describes the fabrication and characterization of nanostructures using a novel nanolithographic technique called Patterning via Optical Saturable Transitions (POST). In this technique the chemical properties of organic photochromic molecules that undergo single-photon reactions are exploited, enabling rapid top-down nanopatterning over large areas at low light intensities, thereby, allowing for the circumvention of the far-field diffraction barrier.4 Simple, cost-effective, high throughput and resolution alternatives to nanopatterning are being explored, such as, two-photon polymerization5,6, beam pen lithography (BPL)7, scanning electron beam lithography (SEBL), and focused ion beam (FIB) patterning. However, multi-photon approaches require high light intensities, which limit their potential for high throughput and offer low image contrast. Although, electron and ion beam lithographic processes offer increased resolution, the serial nature of the process is limited to slow writing speeds, which also prevents patterning of features over large areas. Beam-pen lithography is an approach towards parallel near-field optical lithography. However, the gap between the source of the beam and the surface of the photoresist needs to be controlled extremely precisely for good pattern uniformity and this is very challenging to accomplish for large arrays of beams. Patterning via Optical Saturable Transitions (POST) is an alternative optical nanopatterning technique for patterning sub-wavelength features1-3. Since this technique uses single photons instead of electrons, it is extremely fast and does not require high light intensities1-3, opening the door to massive parallelization.

We report that the diffraction limit of conventional optical lithography can be overcome by exploiting the transitions of organic photochromic derivatives induced by their photoisomerization at low light intensities.1-3 This paper outlines our fabrication technique and two locking mechanisms, namely: dissolution of one photoisomer and electrochemical oxidation.

This protocol describes the fabrication and characterization of nanostructures using a novel nanolithographic technique called Patterning via Optical ...

The Measurement of Unsteady Surface Pressure Using a Remote Microphone Probe

Microphones are widely applied to measure pressure fluctuations at the walls of solid bodies immersed in turbulent flows. Turbulent motions with various characteristic length scales can result in pressure fluctuations over a wide frequency range. This property of turbulence requires sensing devices to have sufficient sensitivity over a wide range of frequencies. Furthermore, the small characteristic length scales of turbulent structures require small sensing areas and the ability to place the sensors in very close proximity to each other. The complex geometries of the solid bodies, often including large surface curvatures or discontinuities, require the probe to have the ability to be set up in very limited spaces. The development of a remote microphone probe, which is inexpensive, consistent, and repeatable, is described in the present communication. It allows for the measurement of pressure fluctuations with high spatial resolution and dynamic response over a wide range of frequencies. The probe is small enough to be placed within the interior of typical wind tunnel models. The remote microphone probe includes a small, rigid, and hollow tube that penetrates the model surface to form the sensing area. This tube is connected to a standard microphone, at some distance away from the surface, using a "T" junction. An experimental method is introduced to determine the dynamic response of the remote microphone probe. In addition, an analytical method for determining the dynamic response is described. The analytical method can be applied in the design stage to determine the dimensions and properties of the RMP components.

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 ...

Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes

Tin selenide (SnSe) belongs to the family of layered metal chalcogenide materials with a buckled structure like phosphorene, and has shown potential for applications in two-dimensional nanoelectronics devices. Although many methods to synthesize SnSe nanocrystals have been developed, a simple way to fabricate large-sized single-layer SnSe flakes remains a great challenge. Herein, we show the experimental method to directly grow large-sized single-layer rectangular SnSe flakes on commonly used SiO2/Si insulating substrates using a straightforward two-step fabrication method in an atmospheric pressure quartz tube furnace system. The single-layer rectangular SnSe flakes with an average thickness of ~6.8 &#197; and lateral dimensions of about 30 &#181;m &#215; 50 &#181;m were fabricated by a combination of vapor transport deposition technique and nitrogen etching route. We characterized the morphology, microstructure, and electrical properties of the rectangular SnSe flakes and obtained excellent crystallinity and good electronic properties. This article about the two-step fabrication method can help researchers grow other similar two-dimensional, large-sized, single-layer materials using an atmospheric pressure system.

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, ...

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.