Name: three-dimensionally printed microfluidic cross-flow system for ultrafiltration/nanofiltration membrane performance testing
Uploaded: 2016-02-13T14:00:00.000+00:00
Duration: 10 min 19 s
Description: Watch this Scientific Journal Video about Three-Dimensionally Printed Microfluidic Cross-flow System for Ultrafiltration/Nanofiltration Membrane Performance Testing at JoVE.com

作者感谢Stratasys公司（以色列雷霍沃特）​​为设备的立体印刷。我们对膜样品感谢Microdyne的最低点（德国）。这项研究是由以色列科学基金会（格兰特1474年至1413年），以支持CJA

1.设计和微流控测试系统的研制<ol><li>设计微流体装置作为两个独立的部分:一顶部，并在CAD程序底部（ 图1）。 </li><li>开始使用矩形工具绘制40毫米乘60毫米矩形使得底部。 </li><li>在一个角落里用圆形工​​具创建一个直径6.2毫米圆圈中央的边10毫米。与线性图案工具复制跨为20mm间距的矩形的孔，共6个孔。 </li><li>使用圆角工具圆角的矩形为1毫米的半径。 </li><li>挤出部10mm的挤压工具。 </li><li>在顶面的中央，用矩形刀具1毫米，并与挤压切口工具创建矩形30毫米切0.2毫米为所述流动通道。 </li><li>使用圆形工具使在流道的末端1毫米直径的圆。然后用直线工具构造圈连接到最近的一个路径40毫米10毫米面，包括与圆角工具制成4毫米半径。请随着席卷切割工具，这条道路切割。 </li><li>用圆形工具创建的流路的中心，3.9毫米直径的圆，切入部8毫米的挤压剪切工具允许配件。 </li><li>重复步骤1.7和1.8为所述流动通道的相对侧。 </li><li>与顶部重复步骤1.2-1.5。然后在顶面中心使用矩形工具创建一个矩形1×30m​​m的创建渗透通道，并使用挤压切割工具切割为0.5mm。 </li><li>使用圆形工具，制成1 mm直径圈从最终渗透通道5毫米中心。与线工具构造由6厘米面，包括与圆角工具制成4毫米半径连接圈的1厘米一个路径。请随着席卷切割工具的路径削减。 </li><li>用圆形工具创建额外的3.9毫米直径的圆与它的渗透路径上的中心和切入部8毫米恩特鲁德切割工具。 </li><li>在零件最40毫米边缘，用矩形工具，5mm的增加4毫米半径与圆角工具创建矩形40毫米。使用拉伸工具向下拉伸3毫米的手柄。 </li><li>使用硬透明聚合物，在0.05毫米对包含信道的每个部分的表面的软橡胶状聚合物涂用多材料光聚合物三维打印机的打印部分。使用制造商的标准协议，校准和设置。 </li><li>丝锥螺纹（M5）成饲料，滞留和渗透口。使用管道工的胶带1/8"接头到饲料和截留和1/16"接头连接到渗透。 </li><li>连接微流体装置泵，阀，压力换能器和背压调节器以1/8"管（ 图2）。 </li><li>连接0.45微米的过滤器进气管。 </li><li>放电渗透到流量计和烧杯上的结余1/16"管道。 </li><l我&gt;附加连续旋转伺服背压用螺丝和标准伺服三通阀领带线调节器。 </li><li>连接伺服系统和电源，伺服盾。 </li><li>压力传感器，开关和伺服屏蔽线连接至微控制器。 </li><li>微控制器，结余，流量计和泵连接到用于数据记录和系统控制的PC。 </li><li>配置余额数据打印到自己的串口。 </li></ol> 2.准备膜进行测试<ol><li>切膜40毫米×8毫米。 </li><li>用超声处理浸泡在超纯水（3×10分钟）的膜。 </li><li>然后浸泡在50/50超纯水/乙醇的膜1小时。 </li><li>冲洗在超纯水中，用超纯水和存储所述膜于4℃。8 </li></ol> 3.准备解决方案进行测试与纳滤膜<ol><li> 500毫升的超纯水加入到锥形瓶中。然后加入0.04克BSA的中ð0.29克氯化钠。 </li><li> 500毫升超纯水的添加到单独的Erlenmeyer烧瓶中。然后加入0.6克硫酸镁的。 </li><li> 500毫升的超纯水加入到第三个Erlenmeyer烧瓶。然后加入0.29克氯化钠。 </li><li>将搅拌棒插入轰动板每个烧瓶和地点瓶。在500rpm混合5分钟。 </li></ol> 4.执行纳污垢实验注:在室温（约24℃）下进行实验。第一配置系统通过关闭阀流向未连接到流量计测量细胞的单一膜。 <ol><li>插入一个泵入口管进入超纯水贮存器和其他入口管进入硫酸镁溶液（ 图2）。 </li><li>用注射器通过管道打水和硫酸镁溶液，以除去系统中的所有气泡。 </li><li>流动池的底部插入的纳米过滤膜，用有源侧朝向进给通道，并在流动池的顶部的地方。 </li><li>紧固用手螺母，然后用扳手均匀地紧固，以便尽量减少漏。 </li><li>选择与贮存器选择器开关的超纯水。 </li><li>设置泵的流速为2毫升/分钟，启动泵。 </li><li>调整压力调节器，以4杆。 </li><li>设置实验参数切换水库每45分钟开始与水水库。 </li><li>将水库切换为自动，并开始实验。 </li><li>在60分钟收集硫酸镁渗透在明年30分钟一管。 </li><li>在91分钟，含有BSA和NaCl的溶液烧瓶代替硫酸镁烧瓶中。 </li><li>迅速停止泵，并使用注射器通过入口管吸取BSA溶液以除去硫酸镁剩余在管。然后重新启动泵。 </li><li>在150分钟收集BSA渗透在明年30分钟一管。 </li><li> 225分钟后，关闭系​​统并卸下纳米<html>从流动池过滤膜。 </li><li>使用注射器，冲洗出测试溶液导入管，用超纯水。 </li><li>重复步骤4.1-4.15每个试验的附加膜。 </li><li>对于氯化钠只测试，重复步骤4.1-4.10，和4.14-4.16更换用NaCl溶液硫酸镁溶液中和结束90分钟而不是225分钟后的实验。 </li></ol>纳滤膜5.计算脱盐<ol><li>漂洗用超纯水的恒电位测试电池的电极。 </li><li>用移液管，存款5微升的硫酸镁溶液到测试电池电极。 </li><li>溶液的记录电阻。 </li><li>重复步骤5.1-5.3四次，并计算其平均值。 </li><li>为NaCl和BSA / NaCl溶液以及对重复步骤5.1-5.4每个渗透液中回收。 </li><li>计算的盐截留等式1: 6eq1.jpg"/&gt; 其中Ωs是测试溶液的电阻和Ωp是渗透的阻力。电阻成反比的溶液，其直接相关盐浓度的导电性。 </li></ol> 6.准备解决方案进行测试与超滤膜<ol><li> 1升的超纯水加入到4升烧杯中。然后加入0.32克BSA的。 </li><li>将搅拌棒插入小的轰动板烧杯和地点。在500rpm混合5分钟。 </li><li>添加额外的3升超纯水至烧杯中，并以500rpm进行5分钟再次混合。 </li></ol> 7.执行超滤实验污垢注:在室温（约24℃）进 ​​行实验。首先配置系统通过打开所有阀门的流动细胞来衡量并行4膜。 <ol><li>将一个泵入口管进入超纯水水库等进口管到日ËBSA溶液（ 图2）。 </li><li>用注射器通过管道吸取水和BSA溶液，以除去系统中的所有气泡。 </li><li>插入超滤膜上流动池的底部，朝向进料通道的活性侧面，并与微流体装置的顶半部关闭细胞。 </li><li>拧紧螺母手，然后用扳手拧紧均匀。不正确的紧缩可能导致漏水。 </li><li>与储层开关选择超纯水。 </li><li>设置泵流速8ml /分钟，并启动泵。 </li><li>调整压力调节到0.4吧。 </li><li>监视用根据制造商的协议数据采集软件膜的通量的值。 </li><li>调整压力调节器，直到平均通量为200的LMH±10％。 </li><li>如果流量不是200 LMH±20％，个别更换膜。 </li><li>进入实验运行参数。首先选择超纯水RESErvoir与200±20台基的恒定通量60分钟。然后，选择的BSA水库420分钟，压力调节器的手动控制。最后，选择超纯水贮存用于与实验结束时的压力调节到冲洗系统的手动控制15分钟。 </li><li>将水库切换为自动，并开始实验。 </li><li>运行完毕后，关闭系​​统关闭，并从流通池去除膜。 </li><li>用注射器，冲洗泵入口管与超纯水。 </li></ol>

<ol>
	<li>Guo, W., Ngo, H. -. H., Li, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+mini-review+on+membrane+fouling.">A mini-review on membrane fouling.</a> Bioresource technol. 122, 27-34 (2012).</li><li>Fane, A. G., Fell, C. J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+fouling+and+fouling+control+in+ultrafiltration.">A review of fouling and fouling control in ultrafiltration.</a> Desalination. 62, 117-136 (1987).</li><li>Tang, C. Y., Chong, T. H., Fane, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Colloidal+interactions+and+fouling+of+NF+and+RO+membranes:+a+review.">Colloidal interactions and fouling of NF and RO membranes: a review.</a> Adv. colloid interfac. 164 (1-2), 126-143 (2011).</li><li>De Jong, J., Lammertink, R. G. H., Wessling, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Membranes+and+microfluidics:+a+review.">Membranes and microfluidics: a review.</a> Lab on a chip. 6 (9), 1125-1139 (2006).</li><li>Haas, R., Gutman, 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=Glycosphingolipids+Enhance+Bacterial+Attachment+and+Fouling+of+Nanofiltration+Membranes.">Glycosphingolipids Enhance Bacterial Attachment and Fouling of Nanofiltration Membranes.</a> Environ. Sci. Technol. Lett. 2, (2015).</li><li>Nabe, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+modification+of+polysulfone+ultrafiltration+membranes+and+fouling+by+BSA+solutions.">Surface modification of polysulfone ultrafiltration membranes and fouling by BSA solutions.</a> J. Membr. Sci. 133 (1), 57-72 (1997).</li><li>Ang, W., Elimelech, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+(BSA)+fouling+of+reverse+osmosis+membranes:+Implications+for+wastewater+reclamation.">Protein (BSA) fouling of reverse osmosis membranes: Implications for wastewater reclamation.</a> J. Membr. Sci. 296 (1-2), 83-92 (2007).</li><li>Bernstein, R., Belfer, S., Freger, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+modification+of+dense+membranes+using+radical+graft+polymerization+enhanced+by+monomer+filtration.">Surface modification of dense membranes using radical graft polymerization enhanced by monomer filtration.</a> Langmuir. 26 (14), 12358-12365 (2010).</li><li>Kaufman, Y., Kasher, R., Lammertink, R. G. H., Freger, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidic+NF/RO+separation:+Cell+design,+performance+and+application.">Microfluidic NF/RO separation: Cell design, performance and application.</a> J. Membr. Sci. 396, 67-73 (2012).</li><li>Kaufman, Y., 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=Towards+supported+bolaamphiphile+membranes+for+water+filtration:+Roles+of+lipid+and+substrate.">Towards supported bolaamphiphile membranes for water filtration: Roles of lipid and substrate.</a> J. Membr. Sci. 457, 50-61 (2014).</li></ol>

作者什么都没有透露。

这个协议描述了用于纳滤和超滤膜的测试的三维印刷的微流体横流装置的设计。最近，我们已经表明该协议与纳米过滤膜调理的变化的成功和鞘糖脂和脂多糖和随后的细菌培养物注入膜的性能差异结垢。5采用这种技术未来的应用可以用于评估具有不同污物膜的性能变化。相比较大的流动池此微流体装置需要更少的测试溶液，并可以显著降低污物和化合物，特别是那些仅在数量有限的成本。小格式也使得它方便了实验室规模的试验，可能是适合高吞吐量的测试。 被THR实现微流体横流装置的设计ough迭代原型，它是立体印刷的主要优势。通用设备的设计特点是基于采用纳滤膜应用先前发布的微横流设备。9,10最显著的设计差异进料和渗透通道但不能抵消而是直接覆盖对方，而的厚度的部件，在水密封方法。漏水的预防是通过用多材料光聚合物三维打印机打印设备克服在设计过程中的重大问题。这使得薄软聚合物是分别与所述膜接触的装置的表面上。在设备中的膜，并用6坚果（M6）的均匀紧固的放置后，被阻止水泄漏。为漏水等电位区是进料口和滞留物出口管路连接点，并且可以使用管道工的磁带被防止与小心不要过度拧紧油管，这将损坏螺纹的连接。该设备已测试压力高达5巴无泄漏。 重要的是，超纯水用于制备所有的解决方案。来自其他来源的水可能含有未知污染物质会导致膜性能降低。另外，过滤器（0.45 mm）需连接到进料管，以确保在该系统的情况下的颗粒物质。渗透流量计是为了使用纳米过滤膜更准确地测量在代表性实验低通量值使用。基于以前的研究鞘糖脂被选择的4条固定压力。使用不同的膜券5重复测量的平均值。在使用超滤膜的代表性实验中，使用0.4巴的压力下测得的膜的初始纯水通量。从膜通量为膜可以变化很大，因此每个膜的通量检查，以确保磁通差异不大于±20％大。落下所需的初始通​​量值以外的膜与新的膜的优惠券被替换。在结垢研究恒定通量可以优选在恒定的压力，因为与不同的初始通量测试膜可以以不同的速率犯规。然后压力调整为200台基的期望的平均初始渗透通量±10％，然而，这些初始起动条件可根据所需的实验条件来选择。随后改变进料溶液组合物中，并监测磁通量变化会给有价值的洞察膜的性能特征。

<html>膜技术是不可或缺需要从本体溶液的溶质中分离的工业等工序，但是，膜污染是一个重大的持续的挑战。其中，膜污染发生包括用于废水的大小基于分离使用超滤膜1常见的例子， 2，薄为离子，以及较大的溶质从微咸水或海水的分离膜复合膜。结垢3特性适应症包括在跨膜压力的增加和通量的下降。这减小了膜的生产效率和其寿命缩短，由于化学或其它清洁协议。因此膜的性能是一个很好的指标来评估污染和理解的机制和污染，生物污染和膜生物膜形成的影响。此外，绩效考核是新的膜设计或修改重要。 EFT"&gt; 在使用中的微流体装置的膜的兴趣一直4生长在过去十年中，最近，我们研究了微生物组分的脂多糖的效果，和鞘糖脂上结垢的纳米过滤膜的表面上，并且经调节的表面微生物的后续敏感性附件5的微流体横流装置是用来评估纳滤膜的性能。这使得仅使用少量的膜表面的污垢可用特殊的非商业脂质成分的，因为膜表面面积是很小的。该系统允许的大小有效地利用膜材料和解决方案的低卷。在这个协议中，我们描述了膜性能测试的微流体设备的设计和制造，并概述该装置的掺入压力流系统。该装置示范被TESTI显示纳克使用模型污物，BSA超滤膜和纳米过滤膜的性能。6,7-

<table><tbody><tr><td>BSA</td><td>SIGMA-ALDRICH</td><td>A6003</td><td></td></tr><tr><td>NaCl</td><td>DAEJUNG</td><td>7548-4100</td><td></td></tr><tr><td>MgSO&lt;sub&gt;4&lt;/sub&gt;</td><td>EMSURE</td><td>1058861000</td><td></td></tr><tr><td>NF Membrane</td><td>Filmtec</td><td>NF200</td><td></td></tr><tr><td>30 kDa UF Membrane</td><td>MICRODYN NADIR</td><td>UH030</td><td></td></tr><tr><td>50 kDa UF Membrane</td><td>MICRODYN NADIR</td><td>UH050</td><td></td></tr><tr><td>Pressure Transducer</td><td>Midas</td><td>43006711</td><td></td></tr><tr><td>Ball Valves</td><td>AV-RF</td><td>Q91SA-PN6.4</td><td></td></tr><tr><td>3-way Valve</td><td>iLife Medical Devices</td><td>902.071</td><td></td></tr><tr><td>Pressure Regulator</td><td>Swagelok</td><td>KCB1G0A2A5P20000</td><td></td></tr><tr><td>Flow-meter</td><td>Bronkhorst</td><td>L01-AGD-99-0-70S</td><td></td></tr><tr><td>Balances</td><td>MRC</td><td>BBA-1200</td><td></td></tr><tr><td>Pump</td><td>Cole-Parmer</td><td>EW-00354-JI</td><td></td></tr><tr><td>1/8&quot; Tubing</td><td>Cole-Parmer</td><td>EW-06605-27</td><td></td></tr><tr><td>1/16&quot; Tubing</td><td>Cole-Parmer</td><td>EW-06407-41</td><td></td></tr><tr><td>1/16&quot; Fittings</td><td>Cole-Parmer</td><td>EW-30486-70</td><td></td></tr><tr><td>1/8&quot; Fittings</td><td>Kiowa</td><td>QSM-B-M5-3-20</td><td></td></tr><tr><td>Microcontroller</td><td>Adafruit</td><td>50</td><td>Arduino UNO R3</td></tr><tr><td>Continuous Rotation Servo</td><td>Adafruit</td><td>154</td><td></td></tr><tr><td>Standard Servo</td><td>Adafruit</td><td>1142</td><td></td></tr><tr><td>Power Supply</td><td>Adafruit</td><td>658</td><td></td></tr><tr><td>Servo Shield</td><td>SainSmart</td><td>20-011-905</td><td></td></tr><tr><td>Switches</td><td>Parts Express</td><td>060-376</td><td></td></tr><tr><td>0.45 Micron Filters</td><td>EMD Millipore</td><td>SLHV033RS</td><td></td></tr><tr><td>Potentiostat</td><td>Gamry</td><td>PCI4</td><td></td></tr><tr><td>Sonicator</td><td>MRC</td><td>DC-150H</td><td></td></tr><tr><td>Connex 3D Printer</td><td>Stratasys</td><td>Objet Connex</td><td></td></tr><tr><td>Veroclear&amp;nbsp;</td><td>Stratasys</td><td>RGD810&amp;nbsp;</td><td>transparent polymer for printing flow cell</td></tr><tr><td>Tangoblack-plus</td><td>Stratasys</td><td>FLX980</td><td>soft rubbery polymer for gasket layers on flow cell</td></tr></tbody></table>

three-dimensionally printed microfluidic cross-flow system for ultrafiltration/nanofiltration membrane performance testing

最小化和膜污染的管理是在不同的工业生产过程和利用膜技术等做法一项艰巨的挑战。理解污染过程可能导致优化和基于膜过滤的更高的效率。这里，我们表明一个自动三维（3-D）印刷的微流体交叉流过滤系统，该系统可并行测试多达4膜的设计和制造。使用多材料光聚合物3-D打印技术，该技术用于在微流体细胞体的透明硬聚合物和掺入一个薄的橡胶状聚合物层，其在操作期间防止泄漏的微流体细胞打印。超滤的性能（UF）和纳滤（NF）膜进行了测试和膜污染可以用一个模型污物牛血清白蛋白（BSA）进行观察。含有BSA饲料的解决方案表现出膜的通量下降。该协议可能会延长ED测量污染或生物污染与许多其他有机，无机或含有微生物的解决方案。微流体设计用于测试材料是昂贵的或仅少量获得，例如多糖，蛋白质，或脂质由于膜的小的表面面积被测试特别有利的。这种模块化系统也可以容易地扩展为膜的高通量测试。

微流体流动池用CAD程序设计和印刷用多材料光聚合物三维（3-D）的打印机。该电池的设计分为两部分，使膜可以很容易地插入并从设备中删除（图1）。每一部分为1厘米厚，从结构完整性硬的，透明的聚合物打印和侧面对着膜被涂覆了橡胶状聚合物的非常薄的50微米层。进行的复涂提供具有密封能力，从而防止漏水的细胞。流动通道被设计为0.2毫米深，宽1毫米和30毫米长，以测试膜的30 平方毫米面积。 8毫米和洗涤协议切割该膜至40mm后，测试膜插入到设备中。六不锈钢螺栓和螺母（M6）被用来拧紧装置，它是连接到系统的（ 图2）。以这种方式，所述细胞是PErmanently连接到系统，而膜可以很容易地更换。一个单元是为纳滤膜实验操作，四个单元在超滤膜的实验平行进行操作。 对于纳米过滤膜，流量计被连接以测量渗透通量。向在2毫升/分钟的速率进行实验，纯水。发起和压力调节至4巴。这导致了〜40 LMH（图3）;渗透液流量，并对应于〜10 LMH /巴。平衡和恒定通量（约45分钟）的观察后，将溶液改为用MgSO 4（10毫米），以测试排斥和验证膜的完整性，并渗透收集。该溶液的电阻率经测定它是成反比的导电性。在所测试的盐浓度，电导率是线性地正比于浓度和％盐ř喷射可以计算。在本实验中测试的膜，得到83％±4％，和64％分别用MgSO 4和NaCl，±3％的拒绝。然后该系统进料返回到纯水直至稳定通量达到了，然后变更为BSA（0.08克/升）的氯化钠（10毫摩尔）的水溶液。相比的10mM的NaCl的条件下的控制膜的通量的通量的下降表明膜由于BSA的结垢。 对于超滤膜，四微流体装置被并联连接，具有渗透通量用天平进行测定。这些余额分别连接到计算机，并促进连续数据收集。用8毫升纯净水进料速率/分的系统，该系统为2毫升/每流动池分钟，将压力以获得200 LMH（图4）的平均通量调节。每个膜的通量被评估，并且该​​膜被替换，如果通量差异＆＃62; 20％的从200台基的初始选择的磁通的平均值。该溶液变为BSA（0.08克/升），并监测磁通减少。然后将进料溶液变回纯净水。为代表性的结果，我们比较了30和50kDa的亲水性聚醚砜的超滤膜，并观察到，虽然50 kDa的膜在实验结束（初始磁通26.5％）与用于30 kDa的膜的23％相比，有较高的归一化的磁通，差异不显著。 <img alt="图1" src="/files/ftp_upload/53556/53556fig1.jpg" /> 图1 的设计和所使用的微流体设备的图像。使用CAD程序所作的设计和使用的三维光聚合物打印机打印。 （A）含有的进给通道（顶视图）底部一部分。 （B）含渗透陈顶部<html>道（顶视图）。设备（侧视图）（三）大会。 （D）包括膜优惠券，用螺母和螺栓固定在一起的部分功能设备的图像。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/53556/53556fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图2" src="/files/ftp_upload/53556/53556fig2.jpg" /> 图2. 该系统的示意图。使用流细胞1.使用所有4个流动池并联进行该超滤膜试验进行该纳米过滤膜的测试。未显示电脑数据记录。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/53556/53556fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> lways"&gt; <img alt="图3" src="/files/ftp_upload/53556/53556fig3.jpg" /> 图3. 性能和横流的条件下，纳米过滤膜的结垢完整的运行（黑色正方形）实验条件:ⅰ）的超纯水，以2ml /分钟，4巴。 ⅱ）的10mM硫酸镁4,2毫升/分钟，4巴。 ⅲ）的超纯水，以2ml /分钟，4巴。 ⅳ）BSA的10mM的氯化钠，以2ml /分钟，4巴（0.08克/升）。 ⅴ）的超纯水，以2ml /分钟，4巴。控制膜10毫摩尔NaCl，以2ml /分钟，4巴（蓝色圆圈）。误差线表示标准偏差。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/53556/53556fig3large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图4" src="/files/ftp_upload/53556/53556fig4.jpg" /> 图4. 污垢超滤膜30千道尔顿（ </s仲&gt; 红色方形 ）和 横流条件下 50 kDa的（ 蓝钻 ）。调整我）压力，使平均初始纯水渗透通量为200 LMH。 ⅱ）的BSA（0.08克/升）2毫升/分。误差线表示标准偏差。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/53556/53556fig4large.jpg" target="_blank">请点击此处查看该图的放大版本。</a>

Watch this Scientific Journal Video about Three-Dimensionally Printed Microfluidic Cross-flow System for Ultrafiltration/Nanofiltration Membrane Performance Testing at JoVE.com

Three-Dimensionally Printed Microfluidic Cross-flow System for Ultrafiltration/Nanofiltration Membrane Performance Testing

设计和三维（3-D）的制造印刷的微流体交叉流过滤系统被证明。该系统用于测试性能和观察超滤和纳滤（薄膜复合）膜的结垢。

超滤/纳滤膜性能测试三维印刷微流控横流系统

Minimization and management of membrane fouling is a formidable challenge in diverse industrial processes and other practices that utilize membrane ...

three-dimensionally-printed-microfluidic-cross-flow-system-for

Universidad San Sebastian

Research

JoVE Journal

Bioengineering

11.2K 次观看.  Ben-Gurion University of the Negev, Sede-Boqer Campus. 设计和三维（3-D）的制造印刷的微流体交叉流过滤系统被证明。该系统用于测试性能和观察超滤和纳滤（薄膜复合）膜的结垢。 

视频: Three-Dimensionally Printed Microfluidic Cross-flow System for Ultrafiltration/Nanofiltration Membrane Performance Testing

Microfluidic Chips Controlled with Elastomeric Microvalve Arrays

Miniaturized microfluidic systems provide simple and effective solutions for low-cost point-of-care diagnostics and high-throughput biomedical assays. Robust flow control and precise fluidic volumes are two critical requirements for these applications. We have developed microfluidic chips featuring elastomeric polydimethylsiloxane (PDMS) microvalve arrays that: 1) need no extra energy source to close the fluidic path, hence the loaded device is highly portable; and 2) allow for microfabricating deep (up to 1 mm) channels with vertical sidewalls and resulting in very precise features.

The PDMS microvalves-based devices consist of three layers: a fluidic layer containing fluidic paths and microchambers of various sizes, a control layer containing the microchannels necessary to actuate the fluidic path with microvalves, and a middle thin PDMS membrane that is bound to the control layer. Fluidic layer and control layers are made by replica molding of PDMS from SU-8 photoresist masters, and the thin PDMS membrane is made by spinning PDMS at specified heights. The control layer is bonded to the thin PDMS membrane after oxygen activation of both, and then assembled with the fluidic layer. The microvalves are closed at rest and can be opened by applying negative pressure (e.g., house vacuum). Microvalve closure and opening are automated via solenoid valves controlled by computer software.

Here, we demonstrate two microvalve-based microfluidic chips for two different applications. The first chip allows for storing and mixing precise sub-nanoliter volumes of aqueous solutions at various mixing ratios. The second chip allows for computer-controlled perfusion of microfluidic cell cultures.

The devices are easy to fabricate and simple to control. Due to the biocompatibility of PDMS, these microchips could have broad applications in miniaturized diagnostic assays as well as basic cell biology studies.

We demonstrate protocols for manufacturing and automating elastomeric polydimethylsiloxane (PDMS)-based microvalve arrays that need no extra energy to close and feature photolithographically defined precise volumes. A parallel subnanoliter-volume mixer and an integrated microfluidic perfusion system are presented.

微流控芯片控制，弹性微阀阵列

Miniaturized microfluidic systems provide simple and effective solutions for low-cost point-of-care diagnostics and high-throughput biomedical assays.  ...

科研

生物学

Procedure for the Development of Multi-depth Circular Cross-sectional Endothelialized Microchannels-on-a-chip

Efforts have been focused on developing in vitro assays for the study of microvessels because in vivo animal studies are more time-consuming, expensive, and observation and quantification are very challenging. However, conventional in vitro microvessel assays have limitations when representing in vivo microvessels with respect to three-dimensional (3D) geometry and providing continuous fluid flow. Using a combination of photolithographic reflowable photoresist technique, soft lithography, and microfluidics, we have developed a multi-depth circular cross-sectional endothelialized microchannels-on-a-chip, which mimics the 3D geometry of in vivo microvessels and runs under controlled continuous perfusion flow. A positive reflowable photoresist was used to fabricate a master mold with a semicircular cross-sectional microchannel network. By the alignment and bonding of the two polydimethylsiloxane (PDMS) microchannels replicated from the master mold, a cylindrical microchannel network was created. The diameters of the microchannels can be well controlled. In addition, primary human umbilical vein endothelial cells (HUVECs) seeded inside the chip showed that the cells lined the inner surface of the microchannels under controlled perfusion lasting for a time period between 4 days to 2 weeks.

A microchannels-on-a-chip platform was developed by the combination of photolithographic reflowable photoresist technique, soft lithography, and microfluidics. The endothelialized microchannels platform mimics the three-dimensional (3D) geometry of in vivo microvessels, runs under controlled continuous perfusion flow, allows for high-quality and real-time imaging&#160;and can be applied for microvascular research.

发展多深的圆形横截面微内皮化的一个芯片的程序

Efforts have been focused on developing in vitro assays for the study of microvessels because in vivo animal studies are more time-consuming, expensive, ...

生物工程

The Submerged Printing of Cells onto a Modified Surface Using a Continuous Flow Microspotter

The printing of cells for microarray applications possesses significant challenges including the problem of maintaining physiologically relevant cell phenotype after printing, poor organization and distribution of desired cells, and the inability to deliver drugs and/or nutrients to targeted areas in the array. Our 3D microfluidic printing technology is uniquely capable of sealing and printing arrays of cells onto submerged surfaces in an automated and multiplexed manner. The design of the microfluidic cell array (MFCA) 3D fluidics enables the printhead tip to be lowered into a liquid-filled well or dish and compressed against a surface to form a seal. The soft silicone tip of the printhead behaves like a gasket and is able to form a reversible seal by applying pressure or backing away. Other cells printing technologies such as pin or ink-jet printers are unable to print in submerged applications. Submerged surface printing is essential to maintain phenotypes of cells and to monitor these cells on a surface without disturbing the material surface characteristics. By printing onto submerged surfaces, cell microarrays are produced that allow for drug screening and cytotoxicity assessment in a multitude of areas including cancer, diabetes, inflammation, infections, and cardiovascular disease.

This 3D microfluidic printing technology prints arrays of cells onto submerged surfaces. We describe how arrays of cells are delivered microfluidically in 3D flow cells onto submerged surfaces. By printing onto submerged surfaces, cell microarrays were produced that allow for drug screening and cytotoxicity assessment in a multitude of areas.

细胞的浸入式印刷到改性表面采用连续流动Microspotter

The printing of cells for microarray applications possesses significant challenges including the problem of maintaining physiologically relevant cell ...

A Multi-Parametric Islet Perifusion System within a Microfluidic Perifusion Device

A microfluidic islet perifusion device was developed for the assessment of dynamic insulin secretion of multiple islets and simultaneous fluorescence imaging of calcium influx and mitochondrial potential changes. The device consists of three layers: first layer contains an array of microscale wells (500 &mu;m diameter and 150 &mu;m depth) that help to immobilize the islets while exposed to flow and maximize the exposed surface area of the islets; the second layer contains a circular perifusion chamber (3 mm deep, 7 mm diameter); and the third layer contains an inlet-mixing channel that fans out before injection into the perifusion chamber (2 mm in width, 19 mm in length, and 500 &mu;m in height) for optimizing the mixing efficiency prior to entering the perifusion chamber. The creation of various glucose gradients including a linear, bell shape, and square shapes also can be created in the microfluidic perifusion network and is demonstrated.

A microfluidic islet perifusion device was developed for the assessment of dynamic insulin secretion of multiple islets and simultaneous fluorescence imaging of calcium influx and mitochondrial potential changes.

一个多参数的胰岛内的微流控Perifusion装置Perifusion系统

A microfluidic islet perifusion device was developed for the assessment of dynamic insulin secretion of multiple islets and simultaneous fluorescence ...

Window on a Microworld: Simple Microfluidic Systems for Studying Microbial Transport in Porous Media

Microbial growth and transport in porous media have important implications for the quality of groundwater and surface water, the recycling of nutrients in the environment, as well as directly for the transmission of pathogens to drinking water supplies. Natural porous media is composed of an intricate physical topology, varied surface chemistries, dynamic gradients of nutrients and electron acceptors, and a patchy distribution of microbes. These features vary substantially over a length scale of microns, making the results of macro-scale investigations of microbial transport difficult to interpret, and the validation of mechanistic models challenging. Here we demonstrate how simple microfluidic devices can be used to visualize microbial interactions with micro-structured habitats, to identify key processes influencing the observed phenomena, and to systematically validate predictive models. Simple, easy-to-use flow cells were constructed out of the transparent, biocompatible and oxygen-permeable material poly(dimethyl siloxane). Standard methods of photolithography were used to make micro-structured masters, and replica molding was used to cast micro-structured flow cells from the masters. The physical design of the flow cell chamber is adaptable to the experimental requirements: microchannels can vary from simple linear connections to complex topologies with feature sizes as small as 2 &mu;m. Our modular EcoChip flow cell array features dozens of identical chambers and flow control by a gravity-driven flow module. We demonstrate that through use of EcoChip devices, physical structures and pressure heads can be held constant or varied systematically while the influence of surface chemistry, fluid properties, or the characteristics of the microbial population is investigated. Through transport experiments using a non-pathogenic, green fluorescent protein-expressing Vibrio bacterial strain, we illustrate the importance of habitat structure, flow conditions, and inoculums size on fundamental transport phenomena, and with real-time particle-scale observations, demonstrate that microfluidics offer a compelling view of a hidden world.

Microfluidic devices can be used to visualize complex natural processes in real time and at the appropriate physical scales. We have developed a simple microfluidic device that mimics key features of natural porous media for studying growth and transport of bacteria in the subsurface.

窗口上的一个微观世界：简单的微流体系统为研究多孔介质中的微生物运输

Microbial growth and transport in porous media have important implications for the quality of groundwater and surface water, the recycling of nutrients in ...

Design and Development of a Three-Dimensionally Printed Microscope Mask Alignment Adapter for the Fabrication of Multilayer Microfluidic Devices

This project aims to develop an easy-to-use and cost-effective platform for the fabrication of precise, multilayer microfluidic devices, which typically can only be achieved using costly equipment in a clean room setting. The key part of the platform is a three dimensionally (3D) printed microscope mask alignment adapter (MMAA) compatible with regular optical microscopes and ultraviolet (UV) light exposure systems. The overall process of creating the device has been vastly simplified because of the work done to optimize the device design. The process entails finding the proper dimensions for the equipment available in the laboratory and 3D-printing the MMAA with the optimized specifications. Experimental results show that the optimized MMAA designed and manufactured by 3D printing performs well with a common microscope and light exposure system. Using a master mold prepared by the 3D-printed MMAA, the resulting microfluidic devices with multilayered structures contain alignment errors of &lt;10 &#181;m, which is sufficient for common microchips. Although human error through transportation of the device to the UV light exposure system can cause larger fabrication errors, the minimal errors achieved in this study are attainable with practice and care. Furthermore, the MMAA can be customized to fit any microscope and UV exposure system by making changes to the modeling file in the 3D printing system. This project provides smaller laboratories with a useful research tool as it only requires the use of equipment that is typically already available to laboratories that produce and use microfluidic devices. The following detailed protocol outlines the design and 3D printing process for the MMAA. In addition, the steps for procuring a multilayer master mold using the MMAA and producing poly(dimethylsiloxane) (PDMS) microfluidic chips is also described herein.

This project allows small laboratories to develop an easy-to-use platform for the fabrication of precise multilayer microfluidic devices. The platform consists of a three-dimensionally printed microscope mask alignment adapter using which multilayer microfluidic devices with alignment errors of &lt;10 &#181;m were achieved.

设计和开发用于制造多层微流体设备的三维打印显微镜面膜对齐适配器

This project aims to develop an easy-to-use and cost-effective platform for the fabrication of precise, multilayer microfluidic devices, which typically ...

工程学

Fabrication of Three-dimensional Paper-based Microfluidic Devices for Immunoassays

Paper wicks fluids autonomously due to capillary action. By patterning paper with hydrophobic barriers, the transport of fluids can be controlled and directed within a layer of paper. Moreover, stacking multiple layers of patterned paper creates sophisticated three-dimensional microfluidic networks that can support the development of analytical and bioanalytical assays. Paper-based microfluidic devices are inexpensive, portable, easy to use, and require no external equipment to operate. As a result, they hold great promise as a platform for point-of-care diagnostics. In order to properly evaluate the utility and analytical performance of paper-based devices, suitable methods must be developed to ensure their manufacture is reproducible and at a scale that is appropriate for laboratory settings. In this manuscript, a method to fabricate a general device architecture that can be used for paper-based immunoassays is described. We use a form of additive manufacturing (multi-layer lamination) to prepare devices that comprise multiple layers of patterned paper and patterned adhesive. In addition to demonstrating the proper use of these three-dimensional paper-based microfluidic devices with an immunoassay for human chorionic gonadotropin (hCG), errors in the manufacturing process that may result in device failures are discussed. We expect this approach to manufacturing paper-based devices will find broad utility in the development of analytical applications designed specifically for limited-resource settings.

We detail a method to fabricate three-dimensional paper-based microfluidic devices for use in the development of immunoassays. Our approach to device assembly is a type of multilayer, additive manufacturing. We demonstrate a sandwich immunoassay to provide representative results for these types of paper-based devices.

三维纸基微流体装置的制造用于免疫分析

Paper wicks fluids autonomously due to capillary action. By patterning paper with hydrophobic barriers, the transport of fluids can be controlled and ...

Rapid Fabrication of Custom Microfluidic Devices for Research and Educational Applications

Microfluidic devices allow for the manipulation of fluids, particles, cells, micro-sized organs or organisms in channels ranging from the nano to submillimeter scales. A rapid increase in the use of this technology in the biological sciences has prompted a need for methods that are accessible to a wide range of research groups. Current fabrication standards, such as PDMS bonding, require expensive and time consuming lithographic and bonding techniques. A viable alternative is the use of equipment and materials that are easily affordable, require minimal expertise and allow for the rapid iteration of designs. In this work we describe a protocol for designing and producing PET-laminates (PETLs), microfluidic devices that are inexpensive, easy to fabricate, and consume significantly less time to generate than other approaches to microfluidics technology. They consist of thermally bonded film sheets, in which channels and other features are defined using a craft cutter. PETLs solve field-specific technical challenges while dramatically reducing obstacles to adoption. This approach facilitates the accessibility of microfluidics devices in both research and educational settings, providing a reliable platform for new methods of inquiry.

Here we present a protocol to design and fabricate custom microfluidic devices with minimal financial and time investment. The aim is to facilitate the adoption of microfluidic technologies in biomedical research laboratories and educational settings.

用于研究和教育应用的定制微流体器件的快速制造

Microfluidic devices allow for the manipulation of fluids, particles, cells, micro-sized organs or organisms in channels ranging from the nano to ...

A Microphysiological System to Study Leukocyte-Endothelial Cell Interaction during Inflammation

Leukocyte-endothelial cell interactions play an important role in inflammatory diseases such as sepsis. During inflammation, excessive migration of activated leukocytes across the vascular endothelium into key organs can lead to organ failure. A physiologically relevant biomimetic microfluidic assay (bMFA) has been developed and validated using several experimental and computational techniques, which can reproduce the entire leukocyte rolling/adhesion/migration cascade to study leukocyte-endothelial cell interactions. Microvascular networks obtained from in vivo images in rodents were digitized using a Geographic Information System (GIS) approach and microfabricated with polydimethylsiloxane (PDMS) on a microscope slide. To study the effect of shear rate and vascular topology on leukocyte-endothelial cell interactions, a Computational Fluid Dynamics (CFD) model was developed to generate a corresponding map of shear rates and velocities throughout the network. The bMFA enables the quantification of leukocyte-endothelial cells interactions, including rolling velocity, number of adhered leukocytes in response to different shear rates, number of migrated leukocytes, endothelial cell permeability, adhesion molecule expression and other important variables. Furthermore, by using human-related samples, such as human endothelial cells and leukocytes, bMFA provides a tool for rapid screening of potential therapeutics to increase their clinical translatability.

In this protocol, a biomimetic microfluid assay, which can reproduce a physiologically relevant microvascular environment and reproduce the entire leukocyte adhesion/migration cascade, is employed to study leukocyte-endothelial cell interactions in inflammatory disease.

一种研究炎症期间白细胞-内皮细胞相互作用的微生理系统

Leukocyte-endothelial cell interactions play an important role in inflammatory diseases such as sepsis. During inflammation, excessive migration of ...

具有开孔和微流控模式的可重构屏障组织平台

Transforming Static Barrier Tissue Models into Dynamic Microphysiological Systems

Microphysiological systems are miniaturized cell culture platforms used to mimic the structure and function of human tissues in a laboratory setting. However, these platforms have not gained widespread adoption in bioscience laboratories where open-well, membrane-based approaches serve as the gold standard for mimicking tissue barriers, despite lacking fluid flow capabilities. This issue can be primarily attributed to the incompatibility of existing microphysiological systems with standard protocols and tools developed for open-well systems.
Here, we present a protocol for creating a reconfigurable membrane-based platform with an open-well structure, flow enhancement capability, and compatibility with conventional protocols. This system utilizes a magnetic assembly approach that enables reversible switching between open-well and microfluidic modes. With this approach, users have the flexibility to begin an experiment in the open-well format using standard protocols and add or remove flow capabilities as needed. To demonstrate the practical usage of this system and its compatibility with standard techniques, an endothelial cell monolayer was established in an open-well format. The system was reconfigured to introduce fluid flow and then switched to the open-well format to conduct immunostaining and RNA extraction. Due to its compatibility with conventional open-well protocols and flow enhancement capability, this reconfigurable design is expected to be adopted by both engineering and bioscience laboratories.

作者聚焦：开发独特的模块化微生理系统来模拟人体屏障组织

This protocol describes a reconfigurable membrane-based cell culture platform that integrates the open-well format with fluid flow capabilities. This platform is compatible with standard protocols and allows for reversible transitions between open-well and microfluidic culture modes, accommodating the needs of both engineering and bioscience laboratories.

将静态屏障组织模型转化为动态微生理系统

Microphysiological systems are miniaturized cell culture platforms used to mimic the structure and function of human tissues in a laboratory setting. ...