This research did not receive any specific grants from funding agencies in the public, commercial, or not-for-profit sectors. Special thanks to Florian Schmittner, Sandro Gorka, Gurinder Singh, Vincent Tran, and Dominik Vu for their contribution on an earlier prototype of the design.

<ol>
	<li>Brettel, M., Friederichsen, N., Keller, M., Rosenberg, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+Virtualization,+Decentralization+and+Network+Building+Change+the+Manufacturing+Landscape:+An+Industry+4.0+Perspective.">How Virtualization, Decentralization and Network Building Change the Manufacturing Landscape: An Industry 4.0 Perspective.</a> World Academy of Science, Engineering and Technology International Journal of Information and Communication Engineering. 8 (1), (2014).</li><li>Gilchrist, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Introducing+Industry+4.0.">Introducing Industry 4.0.</a> Industry 4.0. , 195-215 (2016).</li><li>Petrick, I. J., Simpson, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+Printing+Disrupts+Manufacturing:+How+Economies+of+One+Create+New+Rules+of+Competition.">3D Printing Disrupts Manufacturing: How Economies of One Create New Rules of Competition.</a> Research-Technology Management. 56 (6), 12-16 (2013).</li><li>Wong, K., Hernandez, A. <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+Additive+Manufacturing.">A Review of Additive Manufacturing.</a> ISRN Mechanical Engineering. 10, (2012).</li><li>Lanaro, M., Desselle, M. R., Woodruff, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+Printing+Chocolate:+Properties+of+Formulations+for+Extrusion,+Sintering,+Binding+and+Ink+Jetting.">3D Printing Chocolate: Properties of Formulations for Extrusion, Sintering, Binding and Ink Jetting.</a> Fundamentals of 3D Food printing and Applications. , (2018).</li><li>Godoi, F. C., Prakash, S., Bhandari, B. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3d+printing+technologies+applied+for+food+design:+Status+and+prospects.">3d printing technologies applied for food design: Status and prospects.</a> Journal of Food Engineering. 179, 44-54 (2016).</li><li>Stansbury, J. W., Idacavage, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+printing+with+polymers:+Challenges+among+expanding+options+and+opportunities.">3D printing with polymers: Challenges among expanding options and opportunities.</a> Dental Materials. 32 (1), 54-64 (2016).</li><li>Zhu, W., Ma, X., Gou, M., Mei, D., Zhang, K., Chen, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+printing+of+functional+biomaterials+for+tissue+engineering.">3D printing of functional biomaterials for tissue engineering.</a> Current Opinion in Biotechnology. 40, 103-112 (2016).</li><li>Lanaro, M., Booth, L., Powell, S. K., Woodruff, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrofluidodynamic+technologies+for+biomaterials+and+medical+devices:+melt+electrospinning.">Electrofluidodynamic technologies for biomaterials and medical devices: melt electrospinning.</a> Electrofluidodynamic Technologies (EFDTs) for Biomaterials and Medical Devices. , 37-69 (2018).</li><li>Malone, E., Lipson, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fab@Home:+the+personal+desktop+fabricator+kit+Article+information.">Fab@Home: the personal desktop fabricator kit Article information.</a> Rapid Prototyping Journal. 13 (4), 245-255 (2007).</li><li>Vilbrandt, T., Malone, E., Lipson, H., Pasko, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Universal+Desktop+Fabrication.">Universal Desktop Fabrication.</a> Heterogeneous Objects Modelling and Applications. , 259-284 (2008).</li><li>Jones, R., 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=RepRap-the+replicating+rapid+prototyper.">RepRap-the replicating rapid prototyper.</a> Robotica. 29, 177-191 (2011).</li><li>Lanaro, M., 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=3D+printing+complex+chocolate+objects:+Platform+design,+optimization+and+evaluation.">3D printing complex chocolate objects: Platform design, optimization and evaluation.</a> Journal of Food Engineering. , (2017).</li><li>Wu, W., DeConinck, A., Lewis, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Omnidirectional+Printing+of+3D+Microvascular+Networks.">Omnidirectional Printing of 3D Microvascular Networks.</a> Advanced Materials. 23 (24), H178-H183 (2011).</li><li>Paxton, N., Smolan, W., B&#246;ck, T., Melchels, F., Groll, J., Jungst, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proposal+to+assess+printability+of+bioinks+for+extrusion-based+bioprinting+and+evaluation+of+rheological+properties+governing+bioprintability.">Proposal to assess printability of bioinks for extrusion-based bioprinting and evaluation of rheological properties governing bioprintability.</a> Biofabrication. 9 (4), 044107 (2017).</li></ol>

The authors have nothing to disclose.

This protocol provides detailed instructions for constructing a low-cost melt extrusion-based 3D printer. Construction of the 3D printer can be broken down into subsections including frame, y-axis/bed, x-axis, extruder, electronics, and software. These subsections are presented with detailed diagrams, drawings, files and parts lists. The total price of an ADDME 3D printer comes to $343 AUD ($245 USD as of 01/17/2019), making this the cheapest, reservoir-based melt extrusion 3D printer currently known. It was aimed to mak...

Additive manufacturing is a powerful manufacturing technology that has the potential to provide significant value to the industrial landscape1,2. The attractive features of additive manufacturing involve no tooling costs, high levels of customization, complex geometries, and reduced barriers to entry costs. No retooling costs allow for the rapid manufacturing of prototypes, which is desirable when trying to decrease &#34;time to market&#34;, which is a critical aim of industries in developed nations trying to remain competitive against low-wage competitors1. High levels of customizability allow for a wide variety of products to be fabricated with complex geometries. When these factors are combined with the low costs for set-up, materials, and operator specialization, there is a clear value of additive manufacturing technologies3.
Additive manufacturing, also called 3D printing, involves layer-by-layer fabrication of an object in a computer numerical controlled (CNC) system3. Unlike traditional CNC processes such as milling, in which material is removed from a sheet or block of material, a 3D printing system adds material into the desired structure layer-by-layer.
3D printing can be facilitated through a range of methods including laser, flash, extrusion, or jetting technologies4. The specific technology employed determines the form of the raw material (i.e., powder or melt), as well as the rheological and thermal properties required for processing5. The extrusion-based 3D printing market is dominated by filament-based systems, which is due to filaments being easy to handle, process, and continuously supply large volumes of material to the extrusion head. However, this process is limited by the type of material able to be formed into filaments (mainly thermoplastics). Most materials do not exist in filament form, and the lack of modern low-cost platforms in the market represents a notable gap.
This protocol shows the construction of a reservoir-based extrusion system that allows materials to be stored in a syringe and extruded through a needle. This system is ideally suited to manufacture a wide range of materials including foods6, polymers7, and biomaterials8,9. Furthermore, reservoir-based extrusion techniques are typically less hazardous, lower in cost, and easier to operate than other 3D printing methods.
There is a growing number of university-led teams designing and releasing open-source 3D printing systems to the public. Beginning with the Fab@Home extrusion-based printer in 200710,11, researchers aimed to create a simple and cheap platform to drive rapid expansion in 3D printing technology and applications. Later in 2011, the RepRap project aimed to create a filament-based 3D printing platform designed with parts made by 3D printing, with the goal to create a self-replicating machine12. The cost of 3D printers has been dropping over the years, from $2300 USD for a Fab@Home (2006), $573 USD for a RepRap v1 (2005), and $400 USD for v2 (2011).
In previous work, we demonstrated how an off-the-self 3D printing system could be combined with a custom reservoir-based extrusion system to create complex 3D objects from chocolate13. Further design investigation has shown that considerable cost savings can be achieved compared to this prototype design.
The aim of this protocol is to provide instructions for the construction of a low-cost reservoir-based melt extrusion 3D printer. Presented here are detailed diagrams, drawings, files, and component lists to allow successfully construction and operation of a 3D printer. All components are hosted on the open-source (creative commons noncommercial) platform <a href="https://www.thingiverse.com/Addme/collections" target="_blank">https://www.thingiverse.com/Addme/collections</a>, which allows users to change or add additional features as desired. Viscous cream, chocolate, and Pluronic F-127 (a model for bioinks) are used to evaluate the performance of ADDME and demonstrate application of the ADDME 3D printer to the biomedical and food printing industries.
A laser cutter capable of cutting acrylic and a desktop 3D printer capable of printing PLA or ABS filaments are required for this protocol. A machined heating jacket and heater cartridge or silicone heater can be used to heat the material, depending on which equipment the operator has access to. All CAD files can be found at <a href="https://www.thingiverse.com/Addme/designs" target="_blank">https://www.thingiverse.com/Addme/designs</a>. For firmware and software to control the 3D printer, <a href="http://marlinfw.org/meta/download/" target="_blank">http://marlinfw.org/meta/download/</a> and <a href="https://www.repetier.com/" target="_blank">https://www.repetier.com/</a> are provided resources, respectively. For detailed instructions about the control board, see <a href="https://reprap.org/wiki/RAMPS_1.4" target="_blank">https://reprap.org/wiki/RAMPS_1.4</a>.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>15 W 12V DC 50x100mm Flexible Silicon Heater</td>
			<td>Banggood</td>
			<td>1280175</td>
			<td>Optional; AU$4.46</td>
		</tr>
		<tr>
			<td>3D Printer</td>
			<td>Lulzbot</td>
			<td></td>
			<td><a href="https://download.lulzbot.com/TAZ/6.02/documentation/manual/9780989378482_interior_r6.02.pdf" target="_blank">https://download.lulzbot.com/</a></td>
		</tr>
		<tr>
			<td>3D Printer</td>
			<td>Ultimaker</td>
			<td>Ultimaker 2+</td>
			<td></td>
		</tr>
		<tr>
			<td>AC 100-240V to DC 12V 5A 60W Power Supply</td>
			<td>Banggood</td>
			<td>994870</td>
			<td>AU$12.7</td>
		</tr>
		<tr>
			<td>Acrylic Sheet White Continuous Cast 1200x600mm</td>
			<td>Mulford Plastics</td>
			<td></td>
			<td>AU$36.95</td>
		</tr>
		<tr>
			<td>Allen Keys</td>
			<td>Metric</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Arduino MEGA2560 R3 with RAMPS 1.4 Controller</td>
			<td>Geekcreit</td>
			<td>984594</td>
			<td>AU$28.91</td>
		</tr>
		<tr>
			<td>Carbon Steel Linear Shaft 8mm x 350mm</td>
			<td>Banggood</td>
			<td>1119330</td>
			<td>AU$13.44</td>
		</tr>
		<tr>
			<td>Carbon Steel linear Shaft 8mm x 500mm</td>
			<td>Banggood</td>
			<td>1276011</td>
			<td>AU$19.42</td>
		</tr>
		<tr>
			<td>Chocolate</td>
			<td>Cadbury</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Computer with internet access</td>
			<td>Dell</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Coupler 5-8mm</td>
			<td>Banggood</td>
			<td>1070710</td>
			<td>AU$6.93</td>
		</tr>
		<tr>
			<td>Hand Cream</td>
			<td>Nivea</td>
			<td>80102</td>
			<td></td>
		</tr>
		<tr>
			<td>Heating Cartridge</td>
			<td>Creality 3D</td>
			<td>1192704</td>
			<td>AU$4.75</td>
		</tr>
		<tr>
			<td>K Type Temperature Sensor Thermocouple</td>
			<td>Banggood</td>
			<td>1212169</td>
			<td>AU$2.37</td>
		</tr>
		<tr>
			<td>Laser Cutter</td>
			<td>trotec</td>
			<td>Speedy 300</td>
			<td><a href="https://www.troteclaser.com/fileadmin/content/images/Contact_Support/Manuals/8047-speedy-400-redesign-manual-EN.pdf" target="_blank">https://www.troteclaser.com/</a></td>
		</tr>
		<tr>
			<td>M10 1mm Pitch Thread Metal Hex Nut + Washer</td>
			<td>UXCELL</td>
			<td></td>
			<td>AU$8.84</td>
		</tr>
		<tr>
			<td>M10 1mm Pitch Zinc Plated Pipe 400mm Length</td>
			<td>UXCELL</td>
			<td></td>
			<td>AU$11.62</td>
		</tr>
		<tr>
			<td>M2 - 0.4mm Internal Thread Brass Inserts</td>
			<td>Ebay</td>
			<td></td>
			<td>AU$5.65</td>
		</tr>
		<tr>
			<td>M2 Nuts</td>
			<td>Suleve</td>
			<td>1239291</td>
			<td>AU$9.17</td>
		</tr>
		<tr>
			<td>M2 x 10 mm Button Hex Screws</td>
			<td>Suleve</td>
			<td>1239291</td>
			<td>AU$9.17</td>
		</tr>
		<tr>
			<td>M2 x 5mm Button Hex Screws</td>
			<td>Suleve</td>
			<td>1239291</td>
			<td>AU$9.17</td>
		</tr>
		<tr>
			<td>M3 - 0.5mm Internal Thread Brass Inserts</td>
			<td>Suleve</td>
			<td>1262071</td>
			<td>AU$7.5</td>
		</tr>
		<tr>
			<td>M3 Nuts</td>
			<td>Suleve</td>
			<td>1109208</td>
			<td>AU$7.85</td>
		</tr>
		<tr>
			<td>M3 Washer</td>
			<td>Banggood</td>
			<td>1064061</td>
			<td>AU$3.05</td>
		</tr>
		<tr>
			<td>M3 x 10mm Button Hex Screws</td>
			<td>Suleve</td>
			<td>1109208</td>
			<td>AU$7.85</td>
		</tr>
		<tr>
			<td>M3 x 20mm Button Hex Screws</td>
			<td>Suleve</td>
			<td>1109208</td>
			<td>AU$7.85</td>
		</tr>
		<tr>
			<td>M3 x 6mm Button Hex Screws</td>
			<td>Suleve</td>
			<td>1109208</td>
			<td>AU$7.85</td>
		</tr>
		<tr>
			<td>M3 x 8mm Button Hex Screws</td>
			<td>Suleve</td>
			<td>1109208</td>
			<td>AU$7.85</td>
		</tr>
		<tr>
			<td>M4 x 8mm Button Hex Screws</td>
			<td>Suleve</td>
			<td>1273210</td>
			<td>AU$4.32</td>
		</tr>
		<tr>
			<td>Needle Luer Lock 18 - 27 Gauge</td>
			<td>Terumo</td>
			<td>TGA ARTG ID: 130227</td>
			<td>AU$3.57</td>
		</tr>
		<tr>
			<td>NEMA 17 Stepper Motor</td>
			<td>Casun</td>
			<td>42SHD0001-24B</td>
			<td>AU$54</td>
		</tr>
		<tr>
			<td>NEMA Stepper Motor Mounting Bracket</td>
			<td>Banggood</td>
			<td>ptNema17br90</td>
			<td>AU$4.79</td>
		</tr>
		<tr>
			<td>Pillow Block Flange Bearing 8mm</td>
			<td>Banggood</td>
			<td>KFL08</td>
			<td>AU$5.04</td>
		</tr>
		<tr>
			<td>PLA Filament</td>
			<td>Creality 3D</td>
			<td>1290153</td>
			<td>AU$24.95</td>
		</tr>
		<tr>
			<td>Pluronic F127</td>
			<td>Sigma Aldrich</td>
			<td>P2443-250G</td>
			<td></td>
		</tr>
		<tr>
			<td>SC8UU 8mm Linear Motion Ball Bearing</td>
			<td>Toolcool</td>
			<td>935967</td>
			<td>AU$21.6</td>
		</tr>
		<tr>
			<td>SG-5GL Micro Limit Switch</td>
			<td>Omron</td>
			<td>1225333</td>
			<td>AU$4.5</td>
		</tr>
		<tr>
			<td>Soldering Station</td>
			<td></td>
			<td></td>
			<td>Solder, Wires, Heat shrink e.c.t.</td>
		</tr>
		<tr>
			<td>Spring</td>
			<td>Banggood</td>
			<td>995375</td>
			<td>AU$2.53</td>
		</tr>
		<tr>
			<td>Syringe 3ml Luer Lock Polypropylene</td>
			<td>Brauhn</td>
			<td>9202618N</td>
			<td>AU$3.14</td>
		</tr>
		<tr>
			<td>Timing Pulley GT2 20 Teeth and Belt Set</td>
			<td>Banggood</td>
			<td>10811303</td>
			<td>AU$11.48</td>
		</tr>
		<tr>
			<td>Trapezoidal Lead Screw and Nut 8mm x 400mm</td>
			<td>Banggood</td>
			<td>1095315</td>
			<td>AU$29.02</td>
		</tr>
		<tr>
			<td>Variable Spanner</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

design of an open-source, low-cost bioink and food melt extrusion 3d printer

Three-dimensional (3D) printing is an increasingly popular manufacturing technique that allows highly complex objects to be fabricated with no retooling costs. This increasing popularity is partly driven by falling barriers to entry such as system set-up costs and ease of operation. The following protocol presents the design and construction of an Additive Manufacturing Melt Extrusion (ADDME) 3D printer for the fabrication of custom parts and components. ADDME has been designed with a combination of 3D-printed, laser-cut, and online-sourced components. The protocol is arranged into easy-to-follow sections, with detailed diagrams and parts lists under the headings of framing, y-axis and bed, x-axis, extrusion, electronics, and software. The performance of ADDME is evaluated through extrusion testing and 3D printing of complex objects using viscous cream, chocolate, and Pluronic F-127 (a model for bioinks). The results indicate that ADDME is a capable platform for the fabrication of materials and constructs for use in a wide range of industries. The combination of detailed diagrams and video content facilitates access to low-cost, easy-to-operate equipment for individuals interested in 3D printing of complex objects from a wide range of materials.

The performance of ADDME during 3D printing was evaluated using a viscous cream (150 mL, Nivea hand cream), chocolate (Cadbury, plain milk), and Pluronic F-127 (Sigma Aldrich). The viscous cream and chocolate were used as is, and the Pluronic was dissolved into a 20% wt solution with ultrapure water and stored refrigerated at 5 &#176;C until needed14,15.
Line testing inv...

Watch this Scientific Journal Video about Design of an Open-Source, Low-Cost Bioink and Food Melt Extrusion 3D Printer at JoVE.com

Design of an Open-Source, Low-Cost Bioink and Food Melt Extrusion 3D Printer

The aim of this work is to design and construct a reservoir-based melt extrusion three-dimensional printer made from open-source and low-cost components for applications in the biomedical and food printing industries.

Three-dimensional (3D) printing is an increasingly popular manufacturing technique that allows highly complex objects to be fabricated with no retooling ...

design-an-open-source-low-cost-bioink-food-melt-extrusion-3d

Research

JoVE Journal

Bioengineering

9.7K Views.  Queensland University of Technology (QUT). The aim of this work is to design and construct a reservoir-based melt extrusion three-dimensional printer made from open-source and low-cost components for applications in the biomedical and food printing industries.

Video: Design of an Open-Source, Low-Cost Bioink and Food Melt Extrusion 3D Printer

Low-Cost Cryo-Light Microscopy Stage Fabrication for Correlated Light/Electron Microscopy

The coupling of cryo-light microscopy (cryo-LM) and cryo-electron microscopy (cryo-EM) poses a number of advantages for understanding cellular 
dynamics and ultrastructure. First, cells can be imaged in a near native environment for both techniques. Second, due to the vitrification process, samples are
 preserved by rapid physical immobilization rather than slow chemical fixation. Third, imaging the same sample with both cryo-LM and cryo-EM provides correlation of
 data from a single cell, rather than a comparison of "representative samples". While these benefits are well known from prior studies, the widespread use of correlative 
 cryo-LM and cryo-EM remains limited due to the expense and complexity of buying or building a suitable cryogenic light microscopy stage. Here we demonstrate the 
 assembly, and use of an inexpensive cryogenic stage that can be fabricated in any lab for less than $40 with parts found at local hardware and grocery stores. This 
 cryo-LM stage is designed for use with reflected light microscopes that are fitted with long working distance air objectives. For correlative cryo-LM and cryo-EM 
 studies, we adapt the use of carbon coated standard 3-mm cryo-EM grids as specimen supports. After adsorbing the sample to the grid, previously established protocols 
 for vitrifying the sample and transferring/handling the grid are followed to permit multi-technique imaging. As a result, this setup allows any laboratory with a 
 reflected light microscope to have access to direct correlative imaging of frozen hydrated samples.

We demonstrate the fabrication of a low-cost cryogenic stage designed to fit most reflected light microscopes. This lab-built cryogenic stage enables efficient and reliable correlative imaging between cryo-light and cryo-electron microscopy.

The coupling of cryo-light microscopy (cryo-LM) and cryo-electron microscopy (cryo-EM) poses a number of advantages for understanding cellular 
dynamics ...

High Throughput Microfluidic Rapid and Low Cost Prototyping Packaging Methods

In this work, 3 different packaging and assembly techniques are presented. They can be classified into two categories: one-time use and reusable packaging techniques.
The one-time use packaging technique employs UV-based and temperature curing epoxies to connect microtubes to access holes, wire-bonding for integrated circuit connections, and silver epoxy for electrical connections. This method is based on a robust assembly technique that can support relatively high pressure close to 1 psi and does not need any support to strengthen the microfluidic architecture.
Reusable packaging techniques consist of PDMS-based microtube interconnectors and anisotropic adhesive films for electrical connections. These devices are more sensitive and fragile. Consequently, Plexiglas support is added to the microfluidic structure to improve the electrical contact when anisotropic adhesive films are used, and also to strengthen the microfluidic architecture. In addition, a micromanipulator is needed to maintain tubes while using a thin PDMS layer to connect them to the access holes. Different PDMS layer thicknesses, ranging from 0.45-3 mm, are tested to compare the best adherence versus injection rates. Applied injection rates are varied from 50-300 &#956;l/hr for 0.45-3 mm PDMS layers, respectively. These techniques are mainly applicable for low-pressure applications. However, they can be extended for high-pressure ones through plasma-oxygen process to permanently seal the PDMS to glass substrates. The main advantage of this technique, besides the fact that it is reusable, consists of keeping the device observable when the microchannel length is very short (in the range of 3 mm or lower).

In this article we describe different techniques for microfluidic rapid prototyping platforms. The proposed techniques are based on ultraviolet (UV) sensitive and temperature curing epoxies, polydimethylsiloxane (PDMS) based tubing, wire-bonding, and anisotropic adhesive films. The assembling procedures presented are developed for both one-time use devices as well as reusable microfluidic systems.

In this work, 3 different packaging and assembly techniques are presented. They can be classified into two categories: one-time use and reusable packaging ...

Rapid and Low-cost Prototyping of Medical Devices Using 3D Printed Molds for Liquid Injection Molding

Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications.

We have devised a method for low-cost and rapid prototyping of liquid elastomer rubber injection molded devices by using fused deposition modeling 3D printers for mold design and a modified desiccator as a liquid injection system.

Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using ...

Bioprinting of Cartilage and Skin Tissue Analogs Utilizing a Novel Passive Mixing Unit Technique for Bioink Precellularization

Bioprinting is a powerful technique for the rapid and reproducible fabrication of constructs for tissue engineering applications. In this study, both cartilage and skin analogs were fabricated after bioink pre-cellularization utilizing a novel passive mixing unit technique. This technique was developed with the aim to simplify the steps involved in the mixing of a cell suspension into a highly viscous bioink. The resolution of filaments deposited through bioprinting necessitates the assurance of uniformity in cell distribution prior to printing to avoid the deposition of regions without cells or retention of large cell clumps that can clog the needle. We demonstrate the ability to rapidly blend a cell suspension with a bioink prior to bioprinting of both cartilage and skin analogs. Both tissue analogs could be cultured for up to 4 weeks. Histological analysis demonstrated both cell viability and deposition of tissue specific extracellular matrix (ECM) markers such as glycosaminoglycans (GAGs) and collagen I respectively.

Cartilage and skin analogs were bioprinted using a nanocellulose-alginate based bioink. The bioinks were cellularized prior to printing via a single step passive mixing unit. The constructs were demonstrated to be uniformly cellularized, have high viability, and exhibit favorable markers of differentiation.

Bioprinting is a powerful technique for the rapid and reproducible fabrication of constructs for tissue engineering applications. In this study, both ...

Applications for Open Source Microplate-Compatible Illumination Panels

Microplates are commonly used in the modern laboratory environment for a wide variety of tasks both in small-scale laboratory benchtop operations as well as large-scale high-throughput screening (HTS) campaigns. Though laboratory automation has greatly increased the utility of microplates there remain instances where automation-based instrumentation is not feasible, cost-effective or compatible with microplate formatting needs. In these cases, microplates must be manually prepared. Problematic to manual microplate manipulations is that a number of difficulties can arise pertaining to the accurate tracking of sample operations, data record keeping and quality control (QC) inspection for well artifacts or formatting errors. As microplate well densities increase (i.e., 96-well, 384-well, 1536-well) the potential for introducing errors also drastically increases.&#160; Moreover, for small bench-top laboratory operations there exists a need to improve the ease and accuracy of sample handling in a cost-effective fashion. Herein, we describe a system that acts as a semi-automated pipetting guide referred to as the Microplate Assistive Pipetting Light Emitter (M.A.P.L.E.). &#160;M.A.P.L.E. has multiple uses for supporting compound hit-picking and microplate preparation for assay development in high-throughput screening or laboratory benchtop operations, as well as QC/quality assurance (QA) diagnostic evaluation of microplate quality or visualizing well formatting errors.

Microplate Assistive Pipetting Light Emitter (M.A.P.L.E.) is a computer-driven device that systematically illuminates microtiter wells to provide guidance for the manual preparation of microplates.&#160; M.A.P.L.E. improves the accuracy of microplate preparation while automating data recordkeeping. &#160;In addition, it can assist with examining microplate quality or aid in the detection of errors.&#160; &#160;

Microplates are commonly used in the modern laboratory environment for a wide variety of tasks both in small-scale laboratory benchtop operations as well ...

Pancreatic Tissue-Derived Extracellular Matrix Bioink for Printing 3D Cell-Laden Pancreatic Tissue Constructs

The transplantation of pancreatic islets is a promising treatment for patients who suffer from type 1 diabetes accompanied by hypoglycemia and secondary complications. However, islet transplantation still has several limitations such as the low viability of transplanted islets due to poor islet engraftment and hostile environments. In addition, the insulin-producing cells differentiated from human pluripotent stem cells have limited ability to secrete sufficient hormones that can regulate the blood glucose level; therefore, improving the maturation by culturing cells with proper microenvironmental cues is strongly required. In this article, we elucidate protocols for preparing a pancreatic tissue-derived decellularized extracellular matrix (pdECM) bioink to provide a beneficial microenvironment that can increase glucose sensitivity of pancreatic islets, followed by describing the processes for generating 3D pancreatic tissue constructs using a microextrusion-based bioprinting technique.

Decellularized extracellular matrix (dECM) can provide suitable microenvironmental cues to recapitulate the inherent functions of target tissues in an engineered construct. This article elucidates the protocols for the decellularization of pancreatic tissue, evaluation of pancreatic tissue-derived dECM bioink, and generation of 3D pancreatic tissue constructs using a bioprinting technique.

The transplantation of pancreatic islets is a promising treatment for patients who suffer from type 1 diabetes accompanied by hypoglycemia and secondary ...

An Open Source Technology Platform to Manufacture Hydrogel-Based 3D Culture Models in an Automated and Standardized Fashion

Current mixing steps of viscous materials rely on repetitive and time-consuming tasks which are performed mainly manually in a low throughput mode. These issues represent drawbacks in workflows that can ultimately result in irreproducibility of research findings. Manual-based workflows are further limiting the advancement and widespread adoption of viscous materials, such as hydrogels used for biomedical applications. These challenges can be overcome by using automated workflows with standardized mixing processes to increase reproducibility. In this study, we present step-by-step instructions to use an open source protocol designer, to operate an open source workstation, and to identify reproducible mixtures. Specifically, the open source protocol designer guides the user through the experimental parameter selection and generates a ready-to-use protocol code to operate the workstation. This workstation is optimized for pipetting of viscous materials to enable automated and highly reliable handling by the integration of temperature docks for thermoresponsive materials, positive displacement pipettes for viscous materials, and an optional tip touch dock to remove excess material from the pipette tip. The validation and verification of mixtures are performed by a fast and inexpensive absorbance measurement of Orange G. This protocol presents results to obtain 80% (v/v) glycerol mixtures, a dilution series for gelatin methacryloyl (GelMA), and double network hydrogels of 5% (w/v) GelMA and 2% (w/v) alginate. A troubleshooting guide is included to support users with protocol adoption. The described workflow can be broadly applied to a number of viscous materials to generate user-defined concentrations in an automated fashion.

This protocol serves as a comprehensive tutorial for standardized and reproducible mixing of viscous materials with a novel open source automation technology. Detailed instructions are provided on the operation of a newly developed open source workstation, the usage of an open source protocol designer, and the validation and verification to identify reproducible mixtures.

Current mixing steps of viscous materials rely on repetitive and time-consuming tasks which are performed mainly manually in a low throughput mode. These ...

Low-Cost, Volume-Controlled Dipstick Urinalysis for Home-Testing

Dipstick urinalysis provides quick and affordable estimations of multiple physiological conditions but requires good technique and training to use accurately. Manual performance of dipstick urinalysis relies on good human color vision, proper lighting control, and error-prone, time-sensitive comparisons to chart colors. By automating the key steps in the dipstick urinalysis test, potential sources of error can be eliminated, allowing self-testing at home. We describe the steps necessary to create a customizable device to perform automated urinalysis testing in any environment. The device is cheap to manufacture and simple to assemble. We describe the key steps involved in customizing it for the dipstick of choice and for customizing a mobile phone app to analyze the results. We demonstrate its use to perform urinalysis and discuss the critical measurements and fabrication steps necessary to ensure robust operation. We then compare the proposed method to the dip-and-wipe method, the gold standard technique for dipstick urinalysis.

Dipstick urinalysis is a quick and affordable method of assessing one&#8217;s personal state of health. We present a method to perform accurate, low-cost dipstick urinalysis that removes the primary sources of error associated with traditional dip-and-wipe protocols and is simple enough to be performed by lay users at home.

Dipstick urinalysis provides quick and affordable estimations of multiple physiological conditions but requires good technique and training to use ...

Open-source Toolkit: Benchtop Carbon Fiber Microelectrode Array for Nerve Recording

Conventional peripheral nerve probes are primarily fabricated in a cleanroom, requiring the use of multiple expensive and highly specialized tools. This paper presents a cleanroom "light" fabrication process of carbon fiber neural electrode arrays that can be learned quickly by an inexperienced cleanroom user. This carbon fiber electrode array fabrication process requires just one cleanroom tool, a Parylene C deposition machine, that can be learned quickly or outsourced to a commercial processing facility at marginal cost. This fabrication process also includes hand-populating printed circuit boards, insulation, and tip optimization. 
The three different tip optimizations explored here (Nd:YAG laser, blowtorch, and UV laser) result in a range of tip geometries and 1 kHz impedances, with blowtorched fibers resulting in the lowest impedance. While previous experiments have proven laser and blowtorch electrode efficacy, this paper also shows that UV laser-cut fibers can record neural signals in vivo. Existing carbon fiber arrays either do not have individuated electrodes in favor of bundles or require cleanroom fabricated guides for population and insulation. The proposed arrays use only tools that can be used at a benchtop for fiber population. This carbon fiber electrode array fabrication process allows for quick customization of bulk array fabrication at a reduced price compared to commercially available probes.

Here, we describe fabrication methodology for customizable carbon fiber electrode arrays for recording in vivo in nerve and brain.

Conventional peripheral nerve probes are primarily fabricated in a cleanroom, requiring the use of multiple expensive and highly specialized tools. This ...

Preparation and Characterization of Graphene-Based 3D Biohybrid Hydrogel Bioink for Peripheral Neuroengineering

Peripheral neuropathies can occur as a result of axonal damage, and occasionally due to demyelinating diseases. Peripheral nerve damage is a global problem that occurs in 1.5%-5% of emergency patients and may lead to significant job losses. Today, tissue engineering-based approaches, consisting of scaffolds, appropriate cell lines, and biosignals, have become more applicable with the development of three-dimensional (3D) bioprinting technologies. The combination of various hydrogel biomaterials with stem cells, exosomes, or bio-signaling molecules is frequently studied to overcome the existing problems in peripheral nerve regeneration. Accordingly, the production of injectable systems, such as hydrogels, or implantable conduit structures formed by various bioprinting methods has gained importance in peripheral neuro-engineering. Under normal conditions, stem cells are the regenerative cells of the body, and their number and functions do not decrease with time to protect their populations; these are not specialized cells but can differentiate upon appropriate stimulation in response to injury. The stem cell system is under the influence of its microenvironment, called the stem cell niche. In peripheral nerve injuries, especially in neurotmesis, this microenvironment cannot be fully rescued even after surgically binding severed nerve endings together. The composite biomaterials and combined cellular therapies approach increases the functionality and applicability of materials in terms of various properties such as biodegradability, biocompatibility, and processability. Accordingly, this study aims to demonstrate the preparation and use of graphene-based biohybrid hydrogel patterning and to examine the differentiation efficiency of stem cells into nerve cells, which can be an effective solution in nerve regeneration.

In this manuscript, we demonstrate the preparation of a biohybrid hydrogel bioink containing graphene for use in peripheral tissue engineering. Using this 3D biohybrid material, the neural differentiation protocol of stem cells is performed. This can be an important step in bringing similar biomaterials to the clinic.

Peripheral neuropathies can occur as a result of axonal damage, and occasionally due to demyelinating diseases. Peripheral nerve damage is a global ...