Pneumatic valves in folded 2D and 3D fluidic devices made from plastic films and tapes

Lab on a Chip ◽  
2014 ◽  
Vol 14 (10) ◽  
pp. 1665-1668 ◽  
Author(s):  
Gregory A. Cooksey ◽  
Javier Atencia
Keyword(s):  
Microfluidic Devices ◽  
Plastic Films ◽  
Fluidic Devices ◽  
Pneumatic Valves ◽  
2D And 3D

Elastomeric valves integrated into foldable microfluidic devices built with tapes.

scholarly journals 3D Printed Microfluidics

2020 ◽  
Vol 13 (1) ◽  
pp. 45-65 ◽  
Author(s):  
Anna V. Nielsen ◽  
Michael J. Beauchamp ◽  
Gregory P. Nordin ◽  
Adam T. Woolley
Keyword(s):  
3D Printing ◽  
Early Stage ◽  
Three Dimensional ◽  
Microfluidic Devices ◽  
Fabrication Method ◽  
Size Scale ◽  
Additional Work ◽  
Fluidic Devices ◽  
3D Printed ◽  
Microfabrication Techniques

Traditional microfabrication techniques suffer from several disadvantages, including the inability to create truly three-dimensional (3D) architectures, expensive and time-consuming processes when changing device designs, and difficulty in transitioning from prototyping fabrication to bulk manufacturing. 3D printing is an emerging technique that could overcome these disadvantages. While most 3D printed fluidic devices and features to date have been on the millifluidic size scale, some truly microfluidic devices have been shown. Currently, stereolithography is the most promising approach for routine creation of microfluidic structures, but several approaches under development also have potential. Microfluidic 3D printing is still in an early stage, similar to where polydimethylsiloxane was two decades ago. With additional work to advance printer hardware and software control, expand and improve resin and printing material selections, and realize additional applications for 3D printed devices, we foresee 3D printing becoming the dominant microfluidic fabrication method.

Transient Modelling of Pneumatic Valves in Centrifugal Microfluidic Devices

2016 ◽  
Author(s):  
Michael R. Moon ◽  
Lin Lin
Keyword(s):  
Surface Tension ◽  
Point Of Care ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Novel Technologies ◽  
Fluid Handling ◽  
Pneumatic Valves ◽  
Microfluidic Valves ◽  
And Control ◽  
Micrometer Scale

Point of care medical instruments benefit from compact fluid handling systems in the microliter range. To handle fluid volumes this small, many novel technologies have been studied. Pneumatic valves offer advantages over other microfluidic valves, including robustness and low cost. These valves are used in centrifugal microfluidic devices, a very active area of research, and take advantage of pneumatic and centrifugal pressure to aliquot and control the flow of fluid. The physics of fluids at the micrometer scale are complex and modelling their behavior using CFD software is challenging. Representing adhesion, surface tension, and other multiphase interactions is critical to accurately model microfluidic behavior. Centrifugal devices must also consider Coriolis, centrifugal, and Euler effects. In this study, a pneumatic valve was designed and simulated using commercial CFD software. The device was also fabricated for verification of the simulation. The simulation demonstrated the multiphase interactions of fluid and air within the rotating device. In a transient analysis of the model, a 6 μl volume of water is held in stable equilibrium by a compressed volume of air at low RPM, while at a higher RPM, the fluid is observed to displace the compressed air as a result of Rayleigh-Taylor instability. Actual devices with comparable geometry were built and tested. The behavior of the valve predicted in the model was in agreement with experimental results produced from the actual devices. The results of the simulation captured the stabilizing effect of both pneumatic pressure and surface tension at low RPM, as well as the instability that results from increased centrifugal and Euler pressure at higher RPM.

scholarly journals Design and Fabrication of a Roller Imprinting Device for Microfluidic Device Manufacturing

2008 ◽  
Author(s):  
Athulan Vijayaraghavan ◽  
Stephen V. Jayanathan ◽  
Moneer M. Helu ◽  
David A. Dornfeld
Keyword(s):  
Soft Lithography ◽  
Large Scale ◽  
Microfluidic Devices ◽  
Cost Effective ◽  
Machine Design ◽  
Manufacturing Processes ◽  
Position Measurement ◽  
Fluidic Devices ◽  
Large Scale Manufacture ◽  
Cylindrical Roll

Microfluidic devices are gaining popularity in a variety of applications, ranging from molecular biology to bio-defense. However, the widespread adoption of this technology is constrained by the lack of efficient and cost-effective manufacturing processes. This paper focuses on the roller imprinting process, which is being developed to rapidly and inexpensively fabricate micro-fluidic devices. In this process, a cylindrical roll with raised features on its surface creates imprints by rolling over a fixed workpiece substrate and mechanically deforming it. Roller imprinting aims to replace processes that were developed for laboratory scale prototyping which tend to not be scalable and have high equipment requirements and overheads. We discuss the limitations of PDMS soft lithography in large-scale manufacture of microfluidic devices. We also discuss the design, fabrication, and testing of a simple roller imprinting device. This imprinter has been developed based on the principles of precision machine design and is implemented using a three-axis machine tool for actuation and position measurement. A framework for the micro-machining of precision imprint rolls is also presented.

Polymer-Based Fluidic Devices Integrated with Perforated Conical Nanopores in Freestanding Polymer Membranes

2015 ◽  
Vol 752-753 ◽  
pp. 217-220
Author(s):  
Jun Seo Choi ◽  
Sung Gook Park
Keyword(s):  
Aspect Ratio ◽  
Pore Size ◽  
Nanoimprint Lithography ◽  
Mechanical Stability ◽  
Polymer Membranes ◽  
Microfluidic Devices ◽  
Current Voltage ◽  
Fluidic Devices ◽  
Conical Nanopores ◽  
High Mechanical Stability

Although nanoimprint lithography (NIL) can successfully fabricate structures down to 10 nm [1], it is difficult to produce perforated pores with diameters less than 100 nm in freestanding polymer membranes. Since it requires molding using a stamp with extremely high aspect ratio to achieve high mechanical stability for the membrane fully released from a substrate. We utilized silicon microneedle structures as an imprinting mold that overcomes these issues. Also, pressed self-perfection (PSP) process was employed after nanoimprinting to further reduce the pore size. Additionally, the membranes were integrated with microfluidic devices to measure current-voltage curves in order to determine pore size indirectly.

scholarly journals Microfluidic based Platform for drug screening-A review

2020 ◽  
Vol 11 (3) ◽  
pp. 2999-3004
Author(s):  
Kalpana Seelam ◽  
Daisy Rani A
Keyword(s):  
Drug Screening ◽  
Dynamic Condition ◽  
Microfluidic Devices ◽  
Drug Susceptibility ◽  
Cost Models ◽  
Microfluidic Platforms ◽  
Effective Manner ◽  
2D And 3D ◽  
Body Dynamic ◽  
Very High

There is a lot of requirement to develop a preclinical rapid drug screening devices to treat the throat cancerous patients in effective manner. Very High cost models like animal based, 2d and 3d type models are static drug screening models and they are unable to mimic the human body dynamic condition. So microfluidic platform based drug screening devices will give predetermined and prominent result in rapid drug screening by mimic dynamic body conditions. Now it is required to review what are the developments from last five years in screening the drug for cancer. Recently research is going on microfluidic platforms to screen the efficacy of mixed drugs, drug tolerance, and drug susceptibility. So this study presents the review on what are the advancements in microfluidic platforms for rapid drug screening and for different cancer patients. This study also presents what are the different sensing methodologies of microfluidic devices exists to screen the drug for various cancerous tissues

Fabrication of Microfluidic Devices for the study of Ion transport through Single-Walled Carbon Nanotubes

MRS Advances ◽  
2016 ◽  
Vol 1 (28) ◽  
pp. 2085-2090 ◽  
Author(s):  
Khadija Yazda ◽  
Sophie Roman ◽  
Saïd Tahir ◽  
François Henn ◽  
Vincent Jourdain
Keyword(s):  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Microfluidic Devices ◽  
Single Walled Carbon Nanotubes ◽  
Experimental Conditions ◽  
Single Walled Carbon ◽  
Fluidic Devices ◽  
Excellent Control ◽  
Transport Of Ions ◽  
Walled Carbon Nanotubes

ABSTRACTStudying the transport of ions through single-walled carbon nanotubes (SWCNTs) necessitate the fabrication of a fluidic setup integrating carbon nanotubes. In this article, we report on the development of a simple fabrication protocol of SWCNTs fluidic devices. This protocol allows an excellent control of the system features and of the experimental conditions compared with previously published protocols. Our protocol based on the use of the popular SU-8, the preferred photoresist for the fabrication of high-aspect-ratio patterns, allows one to prepare sealed microfluidic devices incorporating one or several tens of individual carbon nanotubes of length between 20 and 80 µm.

Continuous-Flow Microfluidic Devices for Detection of Bacterial Endospores

2006 ◽  
Author(s):  
Jiandi Wan ◽  
Pavel Landsman ◽  
Bing Xia ◽  
Paul E. Bower ◽  
Volkmar Heinrich ◽  
...  
Keyword(s):  
Steady State ◽  
Continuous Flow ◽  
Microfluidic Devices ◽  
Bacterial Spores ◽  
Cationic Dye ◽  
Bacterial Endospores ◽  
Fluidic Devices ◽  
Higher Sensitivity

Using non-lithographic fabrication methods developed in our laboratory, we prepared continuous-flow microfluidic analyzers. We tested these devices in experiments involving detection of bacterial endospores. The detection was based on the enhancement of the fluorescence of a cationic dye, 3,3′-diethylthiacyanine iodide (THIA), in the presence of spores. We were able to detect as few as ~105 spores when injected in a device. The measurements with the micro-fluidic devices manifested significantly higher sensitivity for bacterial spores than for vegetative bacteria. Such distinction between spores and vegetative bacteria could not be achieved with THIA using steady-state emission measurements.

Surface Modification of Cyclic Olefinic Copolymers for Bio-Mems Microfluidic Devices

2002 ◽  
Vol 729 ◽  
Author(s):  
C. Ahn ◽  
S. Kim ◽  
H. Chao ◽  
S. Murugesan ◽  
G. Beaucage
Keyword(s):  
Injection Molding ◽  
Structural Changes ◽  
Microfluidic Devices ◽  
Injection Molding Process ◽  
Hydrophobic Surfaces ◽  
Molding Process ◽  
Capillary Action ◽  
Plasma Treatments ◽  
Fluidic Devices ◽  
Coated Surfaces

AbstractCyclic Olefin copolymers (COC) are a new class of polymers that may prove to be extremely useful in injection molding of micron scale fluidic devices. In microfluidic devices it is desirable to have a hydrophilic surface such as in flow driven by capillary action. However, such hydrophilic surfaces tend to display protein deposition when contacted with blood unlike hydrophobic surfaces. Alternatives to capillary action are then needed to control fluid flow for hydrophobic surfaces. Our goal in this research is to tune the slightly hydrophobic COC surfaces through simple surface modifications that are amenable to injection molding and other processing methods. In this study, the surface of an injection molded microfluidic component made from COC was modified in order to change the surface properties important to bio-fluidic devices. Some of the techniques used in this study were plasma treatments and ASG (aerosol gel) coating. Plasma treatments were conducted by using O2, CF4 and their combination gas. O2 treated surfaces became hydrophilic with increasing time of treatment. Combining O2 and CF4 made the surfaces more hydrophobic compared to CF4 only. The structural changes after the plasma treatments were examined by ATR (Attenuated Total Reflectance) spectroscopy. Titania and silica particles from the ASG process were synthesized from titanium iso-propoxide and tetraethoxysilane, respectively. Titania coated surfaces became more hydrophilic and the silica coated surfaces did not have much change in their surface characteristics. The hydrophobicity of the plastic surfaces was measured by their contact angle with water. The implication of these treatments on bio-fluidic devices and their adaptation to the injection molding process will also be discussed.

scholarly journals A Recent Approach towards Fluidic Microstrip Devices and Gas Sensors: A Review

Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 229
Author(s):  
Suleiman Aliyu Babale ◽  
Kashif Nisar Paracha ◽  
Sarosh Ahmad ◽  
Sharul Kamal Abdul Rahim ◽  
Zainab Yunusa ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Liquid Metals ◽  
Microfluidic Devices ◽  
Rigid Substrate ◽  
Conducting Path ◽  
Recent Approach ◽  
Microwave Component ◽  
Fluidic Devices ◽  
Communication Devices ◽  
Key Features

This paper aims to review some of the available tunable devices with emphasis on the techniques employed, fabrications, merits, and demerits of each technique. In the era of fluidic microstrip communication devices, versatility and stability have become key features of microfluidic devices. These fluidic devices allow advanced fabrication techniques such as 3D printing, spraying, or injecting the conductive fluid on the flexible/rigid substrate. Fluidic techniques are used either in the form of loading components, switching, or as the radiating/conducting path of a microwave component such as liquid metals. The major benefits and drawbacks of each technology are also emphasized. In this review, there is a brief discussion of the most widely used microfluidic materials, their novel fabrication/patterning methods.

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