The authors acknowledge support from the Office of Naval Research awards N00014-17-12306 and N00014-15-1-2502, as well as from the Air Force Office of Scientific Research award FA9550-13-1-0108 and the National Science Foundation Grant No. 1709238.

1. 3D-printing and Assembly of Syringe Pump
<ol>
	<li>Prepare and 3D-print the syringe pump components
	<ol>
		<li>Download the .STL design files from the Supplemental Files of this paper. 
		NOTE: There are six .STL files, titled &#39;JoVE_Syringe_Clamp_10mL_Size.stl&#39;, &#39;JoVE_Syringe_Platform.stl&#39;, &#39;JoVE_Syringe_Plunger_Connectors.stl&#39;, &#39;JoVE_Syringe_Pump_End_Stop.stl&#39;, &#39;JoVE_Syringe_Pump_Motor_Connector.stl&#39;, and &#39;JoVE_Syringe_Pump_Traveler...

<ol>
	<li>Sackmann, E. K., Fulton, A. L., Beebe, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+present+and+future+role+of+microfluidics+in+biomedical+research.">The present and future role of microfluidics in biomedical research.</a> Nature. 507 (7491), 181-189 (2014).</li><li>Duncombe, T. A., Tentori, A. M., Herr, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidics:+reframing+biological+enquiry.">Microfluidics: reframing biological enquiry.</a> Nature Reviews Molecular Cell Biology. 16 (9), 554-567 (2015).</li><li>Prakadan, S. M., Shalek, A. K., Weitz, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scaling+by+shrinking:+empowering+single-cell+'omics'+with+microfluidic+devices.">Scaling by shrinking: empowering single-cell 'omics' with microfluidic devices.</a> Nature Reviews Genetics. 18 (6), (2017).</li><li>Kim, Y., Langer, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidics+in+nanomedicine.">Microfluidics in nanomedicine.</a> Reviews in Cell Biology and Molecular Medicine. 1, 127-152 (2015).</li><li>Rusconi, R., Garren, M., Stocker, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidics+expanding+the+frontiers+of+microbial+ecology.">Microfluidics expanding the frontiers of microbial ecology.</a> Annual Review of Biophysics. 43, 65-91 (2014).</li><li>Skafte-Pedersen, P., Sabourin, D., Dufva, M., Snakenborg, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi-channel+peristaltic+pump+for+microfluidic+applications+featuring+monolithic+PDMS+inlay.">Multi-channel peristaltic pump for microfluidic applications featuring monolithic PDMS inlay.</a> Lab on a Chip. 9 (20), 3003-3006 (2009).</li><li>Heo, Y. J., Kang, J., Kim, M. J., Chung, W. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tuning-free+controller+to+accurately+regulate+flow+rates+in+a+microfluidic+network.">Tuning-free controller to accurately regulate flow rates in a microfluidic network.</a> Scientific Reports. 6, 23273 (2016).</li><li>Kuczenski, B., LeDuc, P. R., Messner, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pressure-driven+spatiotemporal+control+of+the+laminar+flow+interface+in+a+microfluidic+network.">Pressure-driven spatiotemporal control of the laminar flow interface in a microfluidic network.</a> Lab on a Chip. 7 (5), 647-649 (2007).</li><li>Lake, J. R., Heyde, K. C., Ruder, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-cost+feedback-controlled+syringe+pressure+pumps+for+microfluidics+applications.">Low-cost feedback-controlled syringe pressure pumps for microfluidics applications.</a> PLoS One. 12 (4), (2017).</li><li>Kong, D. S., 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=Open-source,+community-driven+microfluidics+with+metafluidics.">Open-source, community-driven microfluidics with metafluidics.</a> Nature Biotechnology. 35 (6), 523-529 (2017).</li><li>Wijnen, B., Hunt, E. J., Anzalone, G. C., Pearce, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Open-source+syringe+pump+library.">Open-source syringe pump library.</a> PLoS One. 9 (9), e107216 (2014).</li><li>Ferry, M. S., Razinkov, I. A., Hasty, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidics+for+synthetic+biology:+from+design+to+execution.">Microfluidics for synthetic biology: from design to execution.</a> Methods in Enzymology. , 295-372 (2011).</li><li>. Arduino Libraries for Timer.h Available from: <a target="_blank" href="https://github.com/JChristensen/Timer">https://github.com/JChristensen/Timer</a> (2018)</li><li>. Arduino Libraries for AccelStepper.h Available from: <a target="_blank" href="https://github.com/adafruit/AccelStepper">https://github.com/adafruit/AccelStepper</a> (2018)</li><li>Lin, F., 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=Generation+of+dynamic+temporal+and+spatial+concentration+gradients+using+microfluidic+devices.">Generation of dynamic temporal and spatial concentration gradients using microfluidic devices.</a> Lab on a Chip. 4 (3), 164-167 (2004).</li><li>Korczyk, P. M., Cybulski, O., Makulska, S., Garstecki, P. <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+unsteadiness+of+the+rates+of+flow+on+the+dynamics+of+formation+of+droplets+in+microfluidic+systems.">Effects of unsteadiness of the rates of flow on the dynamics of formation of droplets in microfluidic systems.</a> Lab on a Chip. 11 (1), 173-175 (2011).</li></ol>

Here, we presented a new design for a syringe pump system with closed-loop pressure control. This was accomplished by integrating a 3D-printed syringe pump with a piezoresistive pressure sensor and an open-source microcontroller. By employing a PID controller, we were able to precisely control the inlet pressure and provide fast response times while simultaneously maintaining the stability about a set point.
Many experiments using microfluidic devices require a precise fluidic control and expl...

Microfluidic tools have become useful for scientists in biological and chemical research. Due to the low volume utilization, rapid measurement capabilities, and well-defined flow profiles, microfluidics has gained traction in genomic and proteomic research, high-throughput screening, medical diagnostics, nanotechnology, and single-cell analysis1,2,3,4. Furthermore, the flexibility of microfluidic device design readily enables basic science research, such as investigating the spatiotemporal dynamics of cultured bacterial colonies5.
Many types of fluid injection systems have been developed to accurately deliver flow to microfluidic devices. Examples of such injection systems include peristaltic and recirculation pumps6, pressure-controller systems7, and syringe pumps8. These injection systems, including syringe pumps, are often composed of expensive precision engineered components. Augmenting these systems with closed-loop feedback control of pressure in the output flow adds to the cost of these systems. In response, we previously developed a robust, low-cost syringe pump system that uses closed-loop feedback control to regulate outputted flow pressure. By using closed-loop pressure control, the need for expensive precision-engineered components is abrogated9.
The combination of affordable 3D-printing hardware and a significant growth in associated open-source software has made the design and fabrication of microfluidic devices increasingly accessible to researchers from a variety of disciplines10. However, the systems used to drive fluid through these devices remain expensive. To address this need for a low-cost fluid control system, we developed a design that can be fabricated by researchers in the lab, requiring only a small number of assembly steps. Despite its low-cost and straightforward assembly, this system can provide precise flow control and provides an alternative to commercially available, closed-loop syringe pump systems, which can be prohibitively expensive.
Here, we provide protocols for the construction and use of the closed-loop controlled syringe pump system we developed (Figure 1). The fluid handling system is composed of a physical syringe pump inspired by a previous study11, a microcontroller, and a piezoresistive pressure sensor. When assembled and programmed with a proportional-integral-derivative (PID) controller, the system is capable of delivering a well-regulated, pressure-driven flow to microfluidic devices. This provides a low-cost and flexible alternative to high-cost commercial products, enabling a broader group of researchers to use microfluidics in their work.

<table border="0" cellpadding="0" cellspacing="0" width="1268">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:289px;">Arduino IDE</td>
			<td style="width:245px;">Arduino.org</td>
			<td style="width:169px;"></td>
			<td style="width:565px;">Arduino Uno R3 control software</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Header Connector, 2 Positions</td>
			<td>Digi-Key</td>
			<td>WM4000-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Header Connector, 3 Positions</td>
			<td>Digi-Key</td>
			<td>WM4001-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Header Connector, 4 Positions</td>
			<td>Digi-Key</td>
			<td>WM4002-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hook-up Wire, 22 Gauge, Black</td>
			<td>Digi-Key</td>
			<td>1528-1752-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hook-up Wire, 22 Gauge, Blue</td>
			<td>Digi-Key</td>
			<td>1528-1757-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hook-up Wire, 22 Gauge, Red</td>
			<td>Digi-Key</td>
			<td>1528-1750-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hook-up Wire, 22 Gauge, White</td>
			<td>Digi-Key</td>
			<td>1528-1768-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hook-up Wire, 22 Gauge, Yellow</td>
			<td>Digi-Key</td>
			<td>1528-1751-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Instrumentation Amplifier</td>
			<td>Texas Instruments</td>
			<td>INA122P</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microcontroller, Arduino Uno R3</td>
			<td>Arduino.org</td>
			<td>A000066</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Mini Breadboard</td>
			<td>Amazon</td>
			<td>B01IMS0II0</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Power Supply</td>
			<td>BK Precision</td>
			<td>1550</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pressure Sensor</td>
			<td>PendoTech</td>
			<td>PRESS-S-000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Rectangular Connectors, Housings</td>
			<td>Digi-Key</td>
			<td>WM2802-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Rectangular Connectors, Male</td>
			<td>Digi-Key</td>
			<td>WM2565CT-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Resistors, 10k Ohm&#160;</td>
			<td>Digi-Key</td>
			<td>1135-1174-1-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Resistors, 330 Ohm&#160;</td>
			<td>Digi-Key</td>
			<td>330ADCT-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Stepper Motor Driver, EasyDriver</td>
			<td>Digi-Key</td>
			<td>1568-1108-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">USB 2.0 Cable, A-Male to B-Male</td>
			<td>Amazon</td>
			<td>PC045</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">3D Printed Material, Z-ABS&#160;</td>
			<td>Zortrax</td>
			<td></td>
			<td>A variety of colors are available</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">3D Printer</td>
			<td>Zortrax</td>
			<td>M200</td>
			<td>Printing out the syringe pump components</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ball Bearing, 17x6x6mm</td>
			<td>Amazon</td>
			<td>B008X18NWK</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hex Machine Screws, M3x16mm&#160;</td>
			<td>Amazon</td>
			<td>B00W97MTII</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hex Machine Screws, M3x35mm&#160;</td>
			<td>Amazon</td>
			<td>B00W97N2UW</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hex Nut, M3 0.5&#160;</td>
			<td>Amazon</td>
			<td>B012U6PKMO</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hex Nut, M5&#160;</td>
			<td>Amazon</td>
			<td>B012T3C8YQ</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Lathe Round Rod</td>
			<td>Amazon</td>
			<td>B00AUB73HW</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Linear Ball Bearing</td>
			<td>Amazon</td>
			<td>B01IDKG1WO</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Linear Flexible Coupler</td>
			<td>Amazon</td>
			<td>B010MZ8SQU</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Steel Lock Nut, M3 0.5</td>
			<td>Amazon</td>
			<td>B000NBKLOQ</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Stepper Motor, NEMA-17, 1.8o/step</td>
			<td>Digi-Key</td>
			<td>1568-1105-ND</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Syringe, 10mL, Luer-Lok Tip</td>
			<td>BD</td>
			<td>309604</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Threaded Rod</td>
			<td>Amazon</td>
			<td>B01MA5XREY</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1H,1H,2H,2H-Perfluorooctyltrichlorosilane</td>
			<td>FisherScientific</td>
			<td>AAL1660609</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Camera Module</td>
			<td>Raspberry Pi Foundation</td>
			<td>V2</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Compact Oven</td>
			<td>FisherScientific</td>
			<td>PR305220G</td>
			<td>Baking PDMS pre-polymer mixture and the device</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dispensing Needle, 22 Gauge</td>
			<td>McMaster-Carr</td>
			<td>75165A682</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dispensing Needle, 23 Gauge</td>
			<td>McMaster-Carr</td>
			<td>75165A684</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fisherbrand Premium Cover Glasses</td>
			<td>FisherScientific</td>
			<td>12-548-5C</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glass Culture Petri Dish, 130x25mm</td>
			<td>American Educational Products</td>
			<td>7-1500-5</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Plasma Cleaner</td>
			<td>Harrick Plasma</td>
			<td>PDC-32G</td>
			<td>Binding the cover glass with the PDMS device</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Razor Blades</td>
			<td>FisherScientific</td>
			<td>7071A141&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Scotch Magic Tape</td>
			<td>Amazon</td>
			<td>B00RB1YAL6</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Single-board Computer</td>
			<td>Raspberry Pi Foundation</td>
			<td>Raspberry Pi 2 model B</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Smart Spatula</td>
			<td>FisherScientific</td>
			<td>EW-06265-12</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sylgard 184 Silicone Elastomer Kit</td>
			<td>FisherScientific</td>
			<td>NC9644388</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Syringe Filters</td>
			<td>Thermo Scientific</td>
			<td>7252520</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tygon Tubing</td>
			<td>ColeParmer&#160;</td>
			<td>EW-06419-01</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Vacuum Desiccator</td>
			<td>FisherScientific</td>
			<td>08-594-15C</td>
			<td>Degasing PDMS pre-polymer mixture and coating fluorosilane on the master mold</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Weighing Dishes</td>
			<td>FisherScientific</td>
			<td>S67090A</td>
			<td></td>
		</tr>
	</tbody>
</table>

three-dimensional printing of thermoplastic materials to create automated syringe pumps with feedback control for microfluidic applications

Microfluidics has become a critical tool in research across the biological, chemical, and physical sciences. One important component of microfluidic experimentation is a stable fluid handling system capable of accurately providing an inlet flow rate or inlet pressure. Here, we have developed a syringe pump system capable of controlling and regulating the inlet fluid pressure delivered to a microfluidic device. This system was designed using low-cost materials and additive manufacturing principles, leveraging three-dimensional (3D) printing of thermoplastic materials and off-the-shelf components whenever possible. This system is composed of three main components: a syringe pump, a pressure transducer, and a programmable microcontroller. Within this paper, we detail a set of protocols for fabricating, assembling, and programming this syringe pump system. Furthermore, we have included representative results that demonstrate high-fidelity, feedback control of inlet pressure using this system. We expect this protocol will allow researchers to fabricate low-cost syringe pump systems, lowering the entry barrier for the use of microfluidics in biomedical, chemical, and materials research.

Here, we present a protocol for the construction of a feedback-controlled syringe pump system and demonstrate its potential uses for microfluidic applications. Figure 1 shows the connected system of the syringe pump, pressure sensor, microfluidic device, microcontroller, pressure sensor circuit, and stepper motor driver. Detailed callouts for the syringe pump assembly are shown in Figure 2 and the electronic circuit schematic for...

Watch this Scientific Journal Video about Three-dimensional Printing of Thermoplastic Materials to Create Automated Syringe Pumps with Feedback Control for Microfluidic Applications at JoVE.com

Three-dimensional Printing of Thermoplastic Materials to Create Automated Syringe Pumps with Feedback Control for Microfluidic Applications

Here we present a protocol to construct a pressure-controlled syringe pump to be used in microfluidic applications. This syringe pump is made from an&#160;additively manufactured body, off-the-shelf hardware, and open-source electronics. The resulting system is low-cost, straightforward to build, and delivers well-regulated fluid flow to enable rapid microfluidic research.

Microfluidics has become a critical tool in research across the biological, chemical, and physical sciences. One important component of microfluidic ...

This method can help enable research in any field requiring precision liquid handling including molecular, cell, and systems biology, chemical engineering and microfabrication. The main advantage of this approach is that we are able to fabricate low-cost pressure-regulated syringe pumps. This technique should save money across a wide range of disciplines.This technique showcases how we can couple additive manufacturing with open-source electronics to make a useful piece of laboratory instrumentation. To begin, download the STL design files from the supplemental files of this publication. Prepare these files for printing by opening them in a software package dedicated to the conversion of STL model files to executable instruction sets for the 3D printer being used.Ensure that the proper software is being used as some printers will require proprietary software whereas others may be able to print directly from the STL file. Now print the plastic components using acrylonitrile butadiene styrene with a high-quality 3D printer setting. If other common 3D printing materials are being used such as polylactic acid or other thermoplastic elastomers, make sure that the finished mechanical properties are comparable.Once complete, detach the printed parts from the printing platform of the 3D printer. Remove the printed supporting structure from the finished parts. Smooth the printed components by sanding any rough edges using sandpaper.For best results, use sandpaper with a grit size below 220. Make sure all components are smooth before assembling and ensure that all seven parts have been printed. Fasten the stepper motor to a threaded rod using a motor shaft z-axis flexible coupler with set screws.Before continuing, make sure that rotating the stepper motor shaft drives the threaded rod without slippage. Connect the syringe platform to the motor connector by firmly pressing the syringe platform's connection pegs into the mating holes on top of the motor connector. Attach the two parts by fastening four 16 millimeter screws through the motor connector.Now insert two linear ball bearings and a 0.8 millimeter hex nut into the openings located on the bottom of the traveler push. Align the threaded rod on the motor connector through the 0.8 millimeter hex nut in the traveler push. Then insert the two linear shafts through the traveler push in the motor connector.Now place two hex nuts in the hexagonal spaces of the motor connector piece and then use two 16 millimeter screws to tighten the connections securing the linear shafts from moving. Insert the ball bearing into the middle opening of the end stop. Connect the end stop with the assembled components.Place two hex nuts in the hexagonal spaces of the end stop piece and then use two 16 millimeter screws to tighten the connections to affix the end stop to the assembly. Next, attach the syringe plunger female connector piece to the traveler push piece using two steel locknuts and two 16 millimeter screws. Place a 10 milliliter syringe on the top of the pump.Ensure the head of the plunger is aligned into the notch of the syringe plunger female connector piece and that the top of the syringe barrel is fixed into the slot of the motor connector. Now insert the syringe plunger male connector piece into the syringe plunger female connector. Connect the syringe clamp to the syringe platform using two hex nuts and two 35 millimeter screws ensuring the syringe barrel is fixed into the slot of the syringe clamp.Ensure that there is a tight fit between the male and female components securing the plunger in place. Proceed to microfluidic device preparation as detailed in the text protocol. To begin the syringe pump system assembly, remove 80%of the length of the wire insulation and shielding from the pressure sensor's electrical cable using a razor.Be gentle when cutting to ensure the wires are not compromised above the desired length. Once the insulation and shielding are removed, connect the wires to male rectangular connectors. Using a similar approach, remove one to two centimeters of the wire insulation from a stepper motor's leads and connect the wires to male rectangular connectors.Now affix the syringe onto the inlet side of the pressure sensor. Connect the 22 gauge dispensing needle onto the outlet side of the pressure sensor. Slide one end of 0.51 centimeter diameter tubing over the 22 gauge dispensing needle attached to the pressure sensor.Slide the other end of the tubing over a 22 gauge dispensing needle that can be connected to the microfluidic device. Then connect the needle to the inlet port of the microfluidic device. Connect the outlet port of the microfluidic device to a waste disposal reservoir using a 22 gauge needle and 0.51 centimeter diameter tubing similar to the inlet port's connection.Next, assemble the electronic circuit on a prototyping breadboard according to the diagram in the text protocol. Connect the wires from the stepper motor with the stepper motor driver. Then connect the wires from the pressure sensor and the stepper motor driver to the breadboard.Now connect the output signal from the breadboard with the analog input pin on the microcontroller. Connect the logic input pins from the stepper motor driver with the digital pins on the microcontroller. The step input on the stepper motor driver is connected with a pulse width modulated port of digital pins on the microcontroller denoted by a tilde sign.Connect the power supply to the breadboard as shown in the text. Then set the power supply to 10 volts for the breadboard and the stepper motor driver. To control the syringe pressure pumps, first open the Integrated Development Environment or IDE for the open-source microcontroller.Download the Timer. h and ExcelStepper. h libraries to the microcontroller's IDE library directory.Download the controller code titled Dual Pump PID Control.INO. This code is used to control the feedback-controlled syringe pump system with two pumps. Program the controller code so that it fits the experiment being conducted.Modify the control parameters for the timing parameters to fit the desired response and duration of the experiment. Compile and upload the code to the microcontroller before running the experiment. Turn on the power supply for the syringe pump system.Finally, set the voltage to 10 volts for the stepper motor power supply. Shown here are representative results showing how control parameters may be tuned. Modifying the proportional coefficients as shown here lead to different response profiles for the pressure signals.Modifying the integral and differential coefficients also lead to changes in the response profiles. Parameters may be optimized for different experimental designs. Shown here are representative results showing the control and modulation of a laminar flow profile in a microfluidic device.By controlling the inlet pressure at two inlet ports of a Y-shaped microfluidic device, the interface position may be precisely controlled downstream. Following this procedure, other techniques such as cell culturing and microscopy can be performed in order to answer questions related to synthetic gene network regulatory dynamics, cell physiology and biological regulatory networks. These syringe pump systems have enabled more rapid development of microfluidic procedures within our lab group.These devices are an inexpensive and time-efficient way for groups to control flow through many different microfluidic devices. We hope that researchers across a wide range of disciplines will be able to use and extend these pressure-regulated syringe pumps for their microfluidic needs.

three-dimensional-printing-thermoplastic-materials-to-create

Research

JoVE Journal

Bioengineering

12.1K vistas.  University of Pittsburgh. This method can help enable research in any field requiring precision liquid handling including molecular, cell, and systems biology, chemical engineering and microfabrication. The main advantage of this approach is that we are able to fabricate low-cost pressure-regulated syringe pumps. This technique should save money across a wide range of disciplines.This technique showcases how we can couple additive manufacturing with open-source electronics to make a useful piece of laboratory i...