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>

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	<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 border="0" cellpadding="0" cellspacing="0" width="915">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:241px;">BSA</td>
			<td style="width:148px;">SIGMA-ALDRICH</td>
			<td style="width:143px;">A6003</td>
			<td style="width:383px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NaCl</td>
			<td>DAEJUNG</td>
			<td>7548-4100</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">MgSO4</td>
			<td>EMSURE</td>
			<td>1058861000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NF Membrane</td>
			<td>Filmtec</td>
			<td>NF200</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">30 kDa UF Membrane</td>
			<td>MICRODYN NADIR</td>
			<td>UH030</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">50 kDa UF Membrane</td>
			<td>MICRODYN NADIR</td>
			<td>UH050</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pressure Transducer</td>
			<td>Midas</td>
			<td>43006711</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ball Valves</td>
			<td>AV-RF</td>
			<td>Q91SA-PN6.4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">3-way Valve</td>
			<td>iLife Medical Devices</td>
			<td>902.071</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pressure Regulator</td>
			<td>Swagelok</td>
			<td>KCB1G0A2A5P20000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Flow-meter</td>
			<td>Bronkhorst</td>
			<td>L01-AGD-99-0-70S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Balances</td>
			<td>MRC</td>
			<td>BBA-1200</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pump</td>
			<td>Cole-Parmer</td>
			<td style="width:143px;">EW-00354-JI</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1/8&#34; Tubing</td>
			<td>Cole-Parmer</td>
			<td>EW-06605-27</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1/16&#34; Tubing</td>
			<td>Cole-Parmer</td>
			<td>EW-06407-41</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1/16&#34; Fittings</td>
			<td>Cole-Parmer</td>
			<td>EW-30486-70</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1/8&#34; Fittings</td>
			<td>Kiowa</td>
			<td>QSM-B-M5-3-20</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microcontroller</td>
			<td>Adafruit</td>
			<td>50</td>
			<td>Arduino UNO R3</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Continuous Rotation Servo</td>
			<td>Adafruit</td>
			<td>154</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Standard Servo</td>
			<td>Adafruit</td>
			<td>1142</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Power Supply</td>
			<td>Adafruit</td>
			<td>658</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Servo Shield</td>
			<td>SainSmart</td>
			<td>20-011-905</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Switches</td>
			<td>Parts Express</td>
			<td>060-376</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">0.45 Micron Filters</td>
			<td>EMD Millipore</td>
			<td>SLHV033RS</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Potentiostat</td>
			<td>Gamry</td>
			<td>PCI4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sonicator</td>
			<td>MRC</td>
			<td>DC-150H</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Connex 3D Printer</td>
			<td>Stratasys</td>
			<td>Objet Connex</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Veroclear&#160;</td>
			<td>Stratasys</td>
			<td>RGD810&#160;</td>
			<td>transparent polymer for printing flow cell</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">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.remotexs.ntu.edu.sg/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.remotexs.ntu.edu.sg/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.remotexs.ntu.edu.sg/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.remotexs.ntu.edu.sg/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

Nanyang Technological University

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 Picoliter Bioreactor for Microbial Single-cell Analysis: Fabrication, System Setup, and Operation

In this protocol the fabrication, experimental setup and basic operation of the recently introduced microfluidic picoliter bioreactor (PLBR) is described in detail. The PLBR can be utilized for the analysis of single bacteria and microcolonies to investigate biotechnological and microbiological related questions concerning, e.g.&#160;cell growth, morphology, stress response, and metabolite or protein production on single-cell level. The device features continuous media flow enabling constant environmental conditions for perturbation studies, but in addition allows fast medium changes as well as oscillating conditions to mimic any desired environmental situation. To fabricate the single use devices, a silicon wafer containing sub micrometer sized SU-8 structures served as the replication mold for rapid polydimethylsiloxane casting. Chips were cut, assembled, connected, and set up onto a high resolution and fully automated microscope suited for time-lapse imaging, a powerful tool for spatio-temporal cell analysis. Here, the biotechnological platform organism Corynebacterium glutamicum&#160;was seeded into the PLBR and cell growth and intracellular fluorescence were followed over several hours unraveling time dependent population heterogeneity on single-cell level, not possible with conventional analysis methods such as flow cytometry. Besides insights into device fabrication, furthermore, the preparation of the preculture, loading, trapping of bacteria, and the PLBR cultivation of single cells and colonies is demonstrated. These devices will add a new dimension in microbiological research to analyze time dependent phenomena of single bacteria under tight environmental control. Due to the simple and relatively short fabrication process the technology can be easily adapted at any microfluidics lab and simply tailored towards specific needs.

In this protocol the fabrication, setup and basic operation of a microfluidic picoliter bioreactor (PLBR) for single-cell analysis of prokaryotic microorganisms is introduced. Industrially relevant microorganisms were analyzed as proof of principle allowing insights into growth rate, morphology, and phenotypic heterogeneity over certain time periods, hardly possible with conventional methods.

In this protocol the fabrication, experimental setup and basic operation of the recently introduced microfluidic picoliter bioreactor (PLBR) is described ...

科研

生物工程

Systematic Analysis of In Vitro Cell Rolling Using a Multi-well Plate Microfluidic System

A major challenge for cell-based therapy is the inability to systemically target a large quantity of viable cells with high efficiency to tissues of interest following intravenous or intraarterial infusion. Consequently, increasing cell homing is currently studied as a strategy to improve cell therapy. Cell rolling on the vascular endothelium is an important step in the process of cell homing and can be probed in-vitro using a parallel plate flow chamber (PPFC). However, this is an extremely tedious, low throughput assay, with poorly controlled flow conditions. Instead, we used a multi-well plate microfluidic system that enables study of cellular rolling properties in a higher throughput under precisely controlled, physiologically relevant shear flow1,2. In this paper, we show how the rolling properties of HL-60 (human promyelocytic leukemia) cells on P- and E-selectin-coated surfaces as well as on cell monolayer-coated surfaces can be readily examined. To better simulate inflammatory conditions, the microfluidic channel surface was coated with endothelial cells (ECs), which were then activated with tumor necrosis factor-&#945; (TNF-&#945;), significantly increasing interactions with HL-60 cells under dynamic conditions. The enhanced throughput and integrated multi-parameter software analysis platform, that permits rapid analysis of parameters such as rolling velocities and rolling path, are important advantages for assessing cell rolling properties in-vitro. Allowing rapid and accurate analysis of engineering approaches designed to impact cell rolling and homing, this platform may help advance exogenous cell-based therapy.

Systematic Analysis of In Vitro Cell Rolling Using a Multi-well Plate Microfluidic System

This study used a multi-well plate microfluidic system, significantly increasing throughput of cell rolling studies under physiologically relevant shear flow. Given the importance of cell rolling in the multi-step cell homing cascade and the importance of cell homing following systemic delivery of exogenous populations of cells in patients, this system offers potential as a screening platform to improve cell-based therapy.

的系统分析<em&gt;体外</em&gt;细胞滚动使用多孔板微流控系统

A major challenge for cell-based therapy is the inability to systemically target a large quantity of viable cells with high efficiency to tissues of ...

Luminescence Resonance Energy Transfer to Study Conformational Changes in Membrane Proteins Expressed in Mammalian Cells

Luminescence Resonance Energy Transfer, or LRET, is a powerful technique used to measure distances between two sites in proteins within the distance range of 10-100 &#197;. By measuring the distances under various ligated conditions, conformational changes of the protein can be easily assessed. With LRET, a lanthanide, most often chelated terbium, is used as the donor fluorophore, affording advantages such as a longer donor-only emission lifetime, the flexibility to use multiple acceptor fluorophores, and the opportunity to detect sensitized acceptor emission as an easy way to measure energy transfer without the risk of also detecting donor-only signal. Here, we describe a method to use LRET on membrane proteins expressed and assayed on the surface of intact mammalian cells. We introduce a protease cleavage site between the LRET fluorophore pair. After obtaining the original LRET signal, cleavage at that site removes the specific LRET signal from the protein of interest allowing us to quantitatively subtract the background signal that remains after cleavage. This method allows for more physiologically relevant measurements to be made without the need for purification of protein.

We describe here an improved Luminescence Resonance Energy Transfer (LRET) method where we introduce a protease cleavage site between the donor and acceptor fluorophore sites. This modification allows us to obtain specific LRET signals arising from membrane proteins of interest, allowing for the study of membrane proteins without protein purification.

荧光共振能量转移研究构象变化的膜蛋白在哺乳动物细胞中表达

Luminescence Resonance Energy Transfer, or LRET, is a powerful technique used to measure distances between two sites in proteins within the distance range ...

Use of a High-throughput In Vitro Microfluidic System to Develop Oral Multi-species Biofilms

There are few high-throughput in vitro systems which facilitate the development of multi-species biofilms that contain numerous species commonly detected within in vivo oral biofilms. Furthermore, a system that uses natural human saliva as the nutrient source, instead of artificial media, is particularly desirable in order to support the expression of cellular and biofilm-specific properties that mimic the in vivo communities. We describe a method for the development of multi-species oral biofilms that are comparable, with respect to species composition, to supragingival dental plaque, under conditions similar to the human oral cavity. Specifically, this methods article will describe how a commercially available microfluidic system can be adapted to facilitate the development of multi-species oral biofilms derived from and grown within pooled saliva. Furthermore, a description of how the system can be used in conjunction with a confocal laser scanning microscope to generate 3-D biofilm reconstructions for architectural and viability analyses will be presented. Given the broad diversity of microorganisms that grow within biofilms in the microfluidic system (including Streptococcus, Neisseria, Veillonella, Gemella, and Porphyromonas), a protocol will also be presented describing how to harvest the biofilm cells for further subculture&#160;or DNA extraction and analysis. The limits of both the microfluidic biofilm system and the current state-of-the-art data analyses will be addressed. Ultimately, it is envisioned that this article will provide a baseline technique that will improve the study of oral biofilms and aid in the development of additional technologies that can be integrated with the microfluidic platform.

Use of a High-throughput In Vitro Microfluidic System to Develop Oral Multi-species Biofilms

The goal of this methods paper is to describe the use of a microfluidic system for the development of multi-species biofilms that contain species typically identified in human supragingival dental plaque.&#160;Methods to describe biofilm architecture, biofilm viability, and an approach to harvest biofilm for culture-dependent or culture-independent analyses are highlighted.

使用高通量的<em&gt;在体外</em&gt;微流控系统开发口服多物种生物膜

There are few high-throughput in vitro systems which facilitate the development of multi-species biofilms that contain numerous species commonly detected ...

Robotic Production of Cancer Cell Spheroids with an Aqueous Two-phase System for Drug Testing

Cancer cell spheroids present a relevant in vitro model of avascular tumors for anti-cancer drug testing applications. A detailed protocol for producing both mono-culture and co-culture spheroids in a high throughput 96-well plate format is described in this work. This approach utilizes an aqueous two-phase system to confine cells into a drop of the denser aqueous phase immersed within the second aqueous phase. The drop rests on the well surface and keeps cells in close proximity to form a single spheroid. This technology has been adapted to a robotic liquid handler to produce size-controlled spheroids and expedite the process of spheroid production for compound screening applications. Spheroids treated with a clinically-used drug show reduced cell viability with increase in the drug dose. The use of a standard micro-well plate for spheroid generation makes it straightforward to analyze viability of cancer cells of drug-treated spheroids with a micro-plate reader. This technology is straightforward to implement both robotically and with other liquid handling tools such as manual pipettes.

A protocol for robotic printing of cancer cell spheroids in a high throughput 96-well plate format using an aqueous two-phase system is presented.

癌症细胞球体机器人生产与药物测试的双水相系统

Cancer cell spheroids present a relevant in vitro model of avascular tumors for anti-cancer drug testing applications. A detailed protocol for producing ...

Multi-step Variable Height Photolithography for Valved Multilayer Microfluidic Devices

Microfluidic systems have enabled powerful new approaches to high-throughput biochemical and biological analysis. However, there remains a barrier to entry for non-specialists who would benefit greatly from the ability to develop their own microfluidic devices to address research questions. Particularly lacking has been the open dissemination of protocols related to photolithography, a key step in the development of a replica mold for the manufacture of polydimethylsiloxane (PDMS) devices. While the fabrication of single height silicon masters has been explored extensively in literature, fabrication steps for more complicated photolithography features necessary for many interesting device functionalities (such as feature rounding to make valve structures, multi-height single-mold patterning, or high aspect ratio definition) are often not explicitly outlined. 
Here, we provide a complete protocol for making multilayer microfluidic devices with valves and complex multi-height geometries, tunable for any application. These fabrication procedures are presented in the context of a microfluidic hydrogel bead synthesizer and demonstrate the production of droplets containing polyethylene glycol (PEG diacrylate) and a photoinitiator that can be polymerized into solid beads. This protocol and accompanying discussion provide a foundation of design principles and fabrication methods that enables development of a wide variety of microfluidic devices. The details included here should allow non-specialists to design and fabricate novel devices, thereby bringing a host of recently developed technologies to their most exciting applications in biological laboratories.

Multilayer microfluidic devices often involve the fabrication of master molds with complex geometries for functionality. This article presents a complete protocol for multi-step photolithography with valves and variable height features tunable to any application. As a demonstration, we fabricate a microfluidic droplet generator capable of producing hydrogel beads.

多级可变高度的光刻多层带瓣微流体装置

Microfluidic systems have enabled powerful new approaches to high-throughput biochemical and biological analysis. However, there remains a barrier to ...

A High-performance Compact Photoacoustic Tomography System for In Vivo Small-animal Brain Imaging

In vivo small-animal imaging has an important role to play in preclinical studies. Photoacoustic tomography (PAT) is an emerging hybrid imaging modality that shows great potential for both preclinical and clinical applications. Conventional optical parametric oscillator-based PAT (OPO-PAT) systems are bulky and expensive and cannot provide high-speed imaging. Recently, pulsed-laser diodes (PLDs) have been successfully demonstrated as an alternative excitation source for PAT. Pulsed-laser diode PAT (PLD-PAT) has been successfully demonstrated for high-speed imaging on photoacoustic phantoms and biological tissues. This work provides a visualized experimental protocol for in vivo brain imaging using PLD-PAT. The protocol includes the compact PLD-PAT system configuration and its description, animal preparation for brain imaging, and a typical experimental procedure for 2D cross-sectional rat brain imaging. The PLD-PAT system is compact and cost-effective and can provide high-speed, high-quality imaging. Brain images collected in vivo at various scan speeds are presented.

A High-performance Compact Photoacoustic Tomography System for In Vivo Small-animal Brain Imaging

A compact pulsed-laser diode-based photoacoustic tomography (PLD-PAT) system for high-speed in vivo brain imaging in small animals is demonstrated.

高性能紧凑型光声层析成像系统<em&gt;体内</em&gt;小动物脑成像

In vivo small-animal imaging has an important role to play in preclinical studies. Photoacoustic tomography (PAT) is an emerging hybrid imaging modality ...

A Performance-testing Platform for a Conduction Micropump with an FR-4 Copper-clad Electrode Plate

Here, a conduction micropump with symmetric planar electrode pairs prepared on flame-retardant glass-reinforced epoxy (FR-4) copper-clad laminate (CCL) is fabricated. It is used to investigate the influence of chamber dimensions on the performance of a conduction micropump and to determine the reliability of the conduction pump when acetone is used as the working fluid. A testing platform is set up to evaluate conduction micropump performance under different conditions. When the chamber height is 0.2 mm, the pump pressure reaches its peak value.

This paper presents a protocol for the fabrication of a conduction micropump using symmetric planar electrodes on flame-retardant glass-reinforced epoxy (FR-4) copper-clad laminate (CCL) to test the influence of chamber dimensions on the performance of a conduction micropump.

FR-4 铜包电极板导电微泵性能测试平台

Here, a conduction micropump with symmetric planar electrode pairs prepared on flame-retardant glass-reinforced epoxy (FR-4) copper-clad laminate (CCL) is ...

A Millimeter Scale Flexural Testing System for Measuring the Mechanical Properties of Marine Sponge Spicules

Many load bearing biological structures (LBBSs)&#8212;such as feather rachises and spicules&#8212;are small (&#60;1 mm) but not microscopic. Measuring the flexural behavior of these LBBSs is important for understanding the origins of their remarkable mechanical functions.
We describe a protocol for performing three-point bending tests using a custom-built mechanical testing device that can measure forces ranging from 10-5 to 101 N and displacements ranging from 10-7 to 10-2 m. The primary advantage of this mechanical testing device is that the force and displacement capacities can be easily adjusted for different LBBSs. The device&#39;s operating principle is similar to that of an atomic force microscope. Namely, force is applied to the LBBS by a load point that is attached to the end of a cantilever. The load point displacement is measured by a fiber optic displacement sensor and converted into a force using the measured cantilever stiffness. The device&#39;s force range can be adjusted by using cantilevers of different stiffnesses.
The device&#39;s capabilities are demonstrated by performing three-point bending tests on the skeletal elements of the marine sponge Euplectella aspergillum. The skeletal elements&#8212;known as spicules&#8212;are silica fibers that are approximately 50 &#181;m in diameter. We describe the procedures for calibrating the mechanical testing device, mounting the spicules on a three-point bending fixture with a &#8776;1.3 mm span, and performing a bending test. The force applied to the spicule and its deflection at the location of the applied force are measured.

We present a protocol for performing three-point bending tests on sub-millimeter scale fibers using a custom-built mechanical testing device. The device can measure forces ranging from 20 &#181;N up to 10 N and can therefore accommodate a variety of fiber sizes.

测量海洋海绵针力学性能的毫米尺度弯曲试验系统

Many load bearing biological structures (LBBSs)&#8212;such as feather rachises and spicules&#8212;are small (&#60;1 mm) but not microscopic. Measuring the ...

Microfluidic Model to Mimic Initial Event of Neovascularization

Neovascularization is usually initialized from an existing normal vasculature and the biomechanical microenvironment of endothelial cells (ECs) in the initial stage varies dramatically from the following process of neovascularization. Although there are plenty of models to simulate different stages of neovascularization, an in vitro 3D model that capitulates the initial process of neovascularization under the corresponding stimulations of normal vasculature microenvironments is still lacking. Here, we reconstructed an in vitro 3D model that mimics the initial event of neovascularization (MIEN). The MIEN model contains a microfluidic sprouting chip and an automatic control, highly efficient circulation system. A functional, perfusable microchannel coated with endothelium was formed and the process of sprouting was simulated in the microfluidic sprouting chip. The initially physiological microenvironment of neovascularization was recapitulated with the microfluidic control system, by which ECs would be exposed to high luminal shear stress, physiological transendothelial flow, and various vascular endothelial growth factor (VEGF) distributions simultaneously. The MIEN model can be readily applied to the study of neovascularization mechanism and holds a potential promise as a low-cost platform for drug screening and toxicology applications.

Here, we provide a microfluidic chip and an automatically controlled, highly efficient circulation microfluidic system that recapitulates the initial microenvironment of neovascularization, allowing endothelial cells (ECs) to be stimulated by high luminal shear stress, physiological level of transendothelial flow, and various vascular endothelial growth factor (VEGF) distribution simultaneously.

模仿神经血管化初始事件的微流体模型

Neovascularization is usually initialized from an existing normal vasculature and the biomechanical microenvironment of endothelial cells (ECs) in the ...