Configurable 3D Printed Microfluidic Multiport Valves with Axial Compression

In the last decade, the fabrication of microfluidic chips was revolutionized by 3D printing. It is not only used for rapid prototyping of molds, but also for manufacturing of complex chips and even integrated active parts like pumps and valves, which are essential for many microfluidic applications. The manufacturing of multiport injection valves is of special interest for analytical microfluidic systems, as they can reduce the injection to detection dead volume and thus enhance the resolution and decrease the detection limit. Designs reported so far use radial compression of rotor and stator. However, commercially available nonprinted valves usually feature axial compression, as this allows for adjustable compression and the possibility to integrate additional sealing elements. In this paper, we transfer the axial approach to 3D-printed valves and compare two different printing techniques, as well as six different sealing configurations. The tightness of the system is evaluated with optical examination, weighing, and flow measurements. The developed system shows similar performance to commercial or other 3D-printed valves with no measurable leakage for the static case and leakages below 0.5% in the dynamic case, can be turned automatically with a stepper motor, is easy to scale up, and is transferable to other printing methods and materials without design changes.

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Engineering 3D Printed Microfluidic Chips for the Fabrication of Nanomedicines

Pharmaceutics ◽

10.3390/pharmaceutics13122134 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2134

Author(s):

Aytug Kara ◽

Athina Vassiliadou ◽

Baris Ongoren ◽

William Keeble ◽

Richard Hing ◽

...

Keyword(s):

3D Printing ◽

Polymeric Nanoparticles ◽

Scale Up ◽

Unmet Need ◽

Three Dimensional ◽

Cost Effective ◽

Particle Sizes ◽

Microfluidic Chips ◽

Acid Media ◽

3D Printed

Currently, there is an unmet need to manufacture nanomedicines in a continuous and controlled manner. Three-dimensional (3D) printed microfluidic chips are an alternative to conventional PDMS chips as they can be easily designed and manufactured to allow for customized designs that are able to reproducibly manufacture nanomedicines at an affordable cost. The manufacturing of microfluidic chips using existing 3D printing technologies remains very challenging because of the intricate geometry of the channels. Here, we demonstrate the manufacture and characterization of nifedipine (NFD) polymeric nanoparticles based on Eudragit L-100 using 3D printed microfluidic chips with 1 mm diameter channels produced with two 3D printing techniques that are widely available, stereolithography (SLA) and fuse deposition modeling (FDM). Fabricated polymeric nanoparticles showed good encapsulation efficiencies and particle sizes in the range of 50–100 nm. SLA chips possessed better channel resolution and smoother channel surfaces, leading to smaller particle sizes similar to those obtained by conventional manufacturing methods based on solvent evaporation, while SLA manufactured nanoparticles showed a minimal burst effect in acid media compared to nanoparticles fabricated with FDM chips. Three-dimensional printed microfluidic chips are a novel and easily amenable cost-effective strategy to allow for customization of the design process for continuous manufacture of nanomedicines under controlled conditions, enabling easy scale-up and reducing nanomedicine development times, while maintaining high-quality standards.

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Preparation of emulsion for nutrient delivery using 3D printed microfluidic chips

The Pharma Innovation ◽

10.22271/tpi.2021.v10.i2g.5710 ◽

2021 ◽

Vol 10 (2) ◽

pp. 490-494

Author(s):

C Drishya ◽

M Maria Leena ◽

JA Moses ◽

C Anandharamakrishnan

Keyword(s):

Microfluidic Chips ◽

Nutrient Delivery ◽

3D Printed

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Scale-up of High-Pressure FT Synthesis in 3D Printed Stainless Steel Microchannel Microreactors: Experiments and Modeling

Catalysis Today ◽

10.1016/j.cattod.2021.09.038 ◽

2021 ◽

Author(s):

Nafeezuddin Mohammad ◽

Chiemeka Chukwudoro ◽

Sujoy Bepari ◽

Omar Basha ◽

Shyam Aravamudhan ◽

...

Keyword(s):

High Pressure ◽

Stainless Steel ◽

Scale Up ◽

Ft Synthesis ◽

3D Printed

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Fabrication of microfluidic chips using controlled dissolution of 3D printed scaffolds

Journal of Applied Polymer Science ◽

10.1002/app.49524 ◽

2020 ◽

Vol 137 (46) ◽

pp. 49524 ◽

Cited By ~ 3

Author(s):

Tartela Alkayyali ◽

Ali Ahmadi

Keyword(s):

Microfluidic Chips ◽

3D Printed

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Low cost 3D printed clamps for external fixator for developing countries: a biomechanical study

3D Printing in Medicine ◽

10.1186/s41205-020-00084-3 ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

Felix J. Landaeta ◽

Jose Nauaki Shiozawa ◽

Arthur Erdman ◽

Cara Piazza

Keyword(s):

Developing Countries ◽

External Fixation ◽

Axial Compression ◽

External Fixator ◽

Low Cost ◽

Biomechanical Properties ◽

External Fixators ◽

The Novel ◽

Astm Standard ◽

3D Printed

Abstract Background External fixation is a mainstream limb reconstruction technique, most often used after a traumatic injury. Due to the high rates of trauma in developing countries, external fixation devices are often utilized for immediate fracture stabilization and soft tissue repair. Proper external fixation treatment too often still fails to be adopted in these regions due to the high cost and trauma complexity. A novel, inexpensive, unilateral fixator was constructed using 3D printed clamps and other readily available supporting components. ASTM standard F1541 tests were used to assess the biomechanical properties of this novel external fixator. Methods Applicable sections of ASTM standard F1541 were used to determine the biomechanical properties of the novel external fixator. 3D printed clamps modeled using SolidWorks and printed with chopped carbon fibers using a fuse deposition modeling (FDM) based 3D printer by Markforged (Boston, MA) were used. This study included 3 different testing configurations: axial compression, anterior-posterior (AP) bending, and medial-lateral (ML) bending. Using the novel unilateral fixator with 3D printed clamps previously sterilized by autoclave, an input load was applied at a rate of 20 N/s, starting at 0 N via a hydraulic MTS tester Model 359. Force and deformation data were collected at a sampling rate of 30 Hz. There was a load limit of 750 N, or until there was a maximum vertical deformation of 6 mm. Also, 4 key dimensions of the 3D printed clamps were measured pre and post autoclave: diameter, width, height and length. Results The novel external fixator had axial compression, AP and ML bending rigidities of 246.12 N/mm (σ = 8.87 N/mm), 35.98 N/mm (σ = 2.11 N/mm) and 39.60 N/mm (σ =2.60 N/mm), respectively. The 3D printed clamps shrunk unproportionally due to the autoclaving process, with the diameter, width, height and length dimensions shrinking by 2.6%, 0.2%, 1.7% and 0.3%, respectively. Conclusion Overall, the biomechanical properties of the novel fixator with 3D printed clamps assessed in this study were comparable to external fixators that are currently being used in clinical settings. While the biomechanics were comparable, the low cost and readily available components of this design meets the need for low cost external fixators in developing countries that current clinical options could not satisfy. However, further verification and validation routines to determine efficacy and safety must be conducted before this novel fixator can be clinically deployed. Also, the material composition allowed for the clamps to maintain the appropriate shape with minimal dimensional shrinkage that can be accounted for in clamp design.

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Simulation and practice of particle inertial focusing in 3D-printed serpentine microfluidic chips via commercial 3D-printers

Soft Matter ◽

10.1039/d0sm00084a ◽

2020 ◽

Vol 16 (12) ◽

pp. 3096-3105

Author(s):

Pengju Yin ◽

Lei Zhao ◽

Zezhou Chen ◽

Zhiqiang Jiao ◽

Hongyan Shi ◽

...

Keyword(s):

Microfluidic Chips ◽

Inertial Focusing ◽

Particle Focusing ◽

3D Printers ◽

3D Printed

Inertial microfluidic chips were fabricated using commercial 3D-printers and the particle focusing was implemented in channels.

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Typography-Like 3D-Printed Templates for the Lithography-Free Fabrication of Microfluidic Chips

SLAS TECHNOLOGY Translating Life Sciences Innovation ◽

10.1177/2472630319867903 ◽

2019 ◽

Vol 25 (1) ◽

pp. 82-87

Author(s):

Wenqiong Su ◽

Yulong Li ◽

Lulu Zhang ◽

Jiahui Sun ◽

Shuopeng Liu ◽

...

Keyword(s):

Processing Time ◽

Fused Deposition Modeling ◽

Three Dimensional ◽

Cost Effective ◽

Microfluidic Channels ◽

3D Printer ◽

Microfluidic Chips ◽

Fused Deposition ◽

Deposition Modeling ◽

3D Printed

Typography-like templates for polydimethylsiloxane (PDMS) microfluidic chips using a fused deposition modeling (FDM) three-dimensional (3D) printer are presented. This rapid and fast proposed scheme did not require complicated photolithographic fabrication facilities and could deliver resolutions of ~100 μm. Polylactic acid (PLA) was adopted as the material to generate the 3D-printed units, which were then carefully assembled on a glass substrate using a heat-melt-curd strategy. This craft of bonding offers a cost-effective way to design and modify the templates of microfluidic channels, thus reducing the processing time of microfluidic chips. Finally, a flexible microfluidic chip to be employed for cell-based drug screening was developed based on the modularized 3D-printed templates. The lithography-free, typography-like, 3D-printed templates create a modularized fabrication process and promote the prevalence of integrated microfluidic systems with minimal requirements and improved efficiency.

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Combining isotopic and sap flux data to estimate GPP: an alternative ecophysiological approach to eddy-covariance based data

10.5194/egusphere-egu2020-6776 ◽

2020 ◽

Author(s):

Antoine Vernay ◽

Xianglin Tian ◽

Jose Lopez ◽

Niles Hasselquist ◽

Annikki Mäkelä ◽

...

Keyword(s):

Eddy Covariance ◽

Gross Primary Production ◽

Scale Up ◽

Mesophyll Conductance ◽

Flow Measurements ◽

Intrinsic Water Use Efficiency ◽

Use Efficiency ◽

Scots Pine Forest ◽

Sap Flow Measurements ◽

Semi Empirical

<p>Stand-scale estimates of gross primary production (GPP) commonly depend on eddy-covariance or eddy-covariance derived models. Chamber-based methods provide an alternative, but they are tricky to scale up to the stand. We estimate GPP by combining isotopic &#948;<sup>13</sup>C of phloem sugars with sap-flow measurements. The method consists of calculating intrinsic water-use efficiency and transpiration to determine GPP. We have improved this approach by considering mesophyll conductance and seasonal variation in photosynthetic capacity and then compared our results to a semi-empirical eddy-covariance based model, PRELES. We compared a fertilised plot and an unfertilised plot in a monospecific Scots pine forest in northern Sweden. The method captured both the stand response to fertilisation and seasonal patterns, as PRELES did. Our results demonstrate the importance of considering a finite mesophyll conductance value to avoid an unreasonable overestimate of GPP. We have now applied the method in a mixed boreal forest where we will partition total stand GPP among the three dominant tree species (pine, spruce, and birch). This approach provides an independent test of GPP estimates and provides a means of estimating GPP where eddy-covariance assumptions are not met.</p>

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