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 Controller for microfluidic large-scale integration

2017 ◽  
Author(s):  
Jonathan A White ◽  
Aaron M Streets
Keyword(s):  
High Throughput ◽  
Personal Computer ◽  
Large Scale ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Fluid Handling ◽  
Large Scale Integration ◽  
Scale Integration ◽  
Microfluidic Valves ◽  
Python Package

AbstractMicrofluidic devices with integrated valves provide precise, programmable fluid handling platforms for high-throughput biological or chemical assays. However, setting up the infrastructure to control such platforms often requires specific engineering expertise or expensive commercial solutions. To address these obstacles, we present a Kit for Arduino-based Transistor Array Actuation (KATARA), an open-source and low-cost Arduino-based controller that can drive 70 solenoid valves to pneumatically actuate integrated microfluidic valves. We include a python package with a GUI to control the KATARA from a personal computer. No programming experience is required.

scholarly journals Negligible-cost microfluidic device fabrication using 3D-printed interconnecting channel scaffolds

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0245206
Author(s):  
Harry Felton ◽  
Robert Hughes ◽  
Andrea Diaz-Gaxiola
Keyword(s):  
Rapid Prototyping ◽  
Point Of Care ◽  
Low Cost ◽  
Microfluidic Channel ◽  
Microfluidic Devices ◽  
Device Fabrication ◽  
Appropriate Technology ◽  
Channel Cross Section ◽  
Microfluidic Systems ◽  
3D Printed

This paper reports a novel, negligible-cost and open-source process for the rapid prototyping of complex microfluidic devices in polydimethylsiloxane (PDMS) using 3D-printed interconnecting microchannel scaffolds. These single-extrusion scaffolds are designed with interconnecting ends and used to quickly configure complex microfluidic systems before being embedded in PDMS to produce an imprint of the microfluidic configuration. The scaffolds are printed using common Material Extrusion (MEX) 3D printers and the limits, cost & reliability of the process are evaluated. The limits of standard MEX 3D-printing with off-the-shelf printer modifications is shown to achieve a minimum channel cross-section of 100×100 μm. The paper also lays out a protocol for the rapid fabrication of low-cost microfluidic channel moulds from the thermoplastic 3D-printed scaffolds, allowing the manufacture of customisable microfluidic systems without specialist equipment. The morphology of the resulting PDMS microchannels fabricated with the method are characterised and, when applied directly to glass, without plasma surface treatment, are shown to efficiently operate within the typical working pressures of commercial microfluidic devices. The technique is further validated through the demonstration of 2 common microfluidic devices; a fluid-mixer demonstrating the effective interconnecting scaffold design, and a microsphere droplet generator. The minimal cost of manufacture means that a 5000-piece physical library of mix-and-match channel scaffolds (100 μm scale) can be printed for ~$0.50 and made available to researchers and educators who lack access to appropriate technology. This simple yet innovative approach dramatically lowers the threshold for research and education into microfluidics and will make possible the rapid prototyping of point-of-care lab-on-a-chip diagnostic technology that is truly affordable the world over.

Research Progress of Paper-Based Microfluidic Devices

2013 ◽  
Vol 421 ◽  
pp. 334-336 ◽  
Author(s):  
Yong Qiang Cheng ◽  
Cui Lian Guo ◽  
Yang Li ◽  
Bin Zhao ◽  
Xiao Cui
Keyword(s):  
Environmental Monitoring ◽  
Plasma Etching ◽  
Biological Samples ◽  
Recent Progress ◽  
Point Of Care ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Research Progress ◽  
Potential Applications

Paper-based microfluidic devices have recently received increasing attention as a potential platform for its low cost, portability and excellent compatibility with biological samples. A variety of fabrication technologies were employed, including simple photolithography, wax plotting, printing, inkjet etching, plasma etching and so on. Meanwhile, the potential applications of paper-based microfluidic devices in diagnostic, point-of-care (POC), and environmental monitoring were reported. We review the recent progress of fabrication technologies and the applications of paper-based microfluidic devices.

Simple, low-cost fabrication of semi-circular channel using the surface tension of solder paste and its application to microfluidic valves

2018 ◽  
Vol 39 (12) ◽  
pp. 1460-1465
Author(s):  
Sheng Yan ◽  
Yuxing Li ◽  
Yuanqing Zhu ◽  
Minsu Liu ◽  
Qianbin Zhao ◽  
...  
Keyword(s):  
Surface Tension ◽  
Low Cost ◽  
Solder Paste ◽  
Circular Channel ◽  
Microfluidic Valves

scholarly journals Modifying Wicking Speeds in Paper-Based Microfluidic Devices by Laser-Etching

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 773
Author(s):  
Brent Kalish ◽  
Mick Kyle Tan ◽  
Hideaki Tsutsui
Keyword(s):  
Flow Control ◽  
Point Of Care ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Diagnostic Tools ◽  
Laser Etching ◽  
Simple Process ◽  
Channel Geometry ◽  
Fluid Delivery ◽  
Reaction Zones

Paper-based microfluidic devices are an attractive platform for developing low-cost, point-of-care diagnostic tools. As paper-based devices’ detection chemistries become more complex, more complicated devices are required, often entailing the sequential delivery of different liquids or reagents to reaction zones. Most research into flow control has been focused on introducing delays. However, delaying the flow can be problematic due to increased evaporation leading to sample loss. We report the use of a CO2 laser to uniformly etch the surface of the paper to modify wicking speeds in paper-based microfluidic devices. This technique can produce both wicking speed increases of up to 1.1× faster and decreases of up to 0.9× slower. Wicking speeds can be further enhanced by etching both sides of the paper, resulting in wicking 1.3× faster than unetched channels. Channels with lengthwise laser-etched grooves were also compared to uniformly etched channels, with the most heavily grooved channels wicking 1.9× faster than the fastest double-sided etched channels. Furthermore, sealing both sides of the channel in packing tape results in the most heavily etched channels, single-sided, double-sided, and grooved, wicking over 13× faster than unetched channels. By selectively etching individual channels, different combinations of sequential fluid delivery can be obtained without altering any channel geometry. Laser etching is a simple process that can be integrated into the patterning of the device and requires no additional materials or chemicals, enabling greater flow control for paper-based microfluidic devices.

scholarly journals Biosensing on the Centrifugal Microfluidic Lab-on-a-Disc Platform

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1360
Author(s):  
Celina M. Miyazaki ◽  
Eadaoin Carthy ◽  
David J. Kinahan
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Analytical Data ◽  
Perfect Match ◽  
Novel Technologies ◽  
Detection Systems ◽  
Manual Intervention ◽  
Global Pandemic ◽  
Recent Developments ◽  
Fluidic Control

Lab-on-a-Disc (LoaD) biosensors are increasingly a promising solution for many biosensing applications. In the search for a perfect match between point-of-care (PoC) microfluidic devices and biosensors, the LoaD platform has the potential to be reliable, sensitive, low-cost, and easy-to-use. The present global pandemic draws attention to the importance of rapid sample-to-answer PoC devices for minimising manual intervention and sample manipulation, thus increasing the safety of the health professional while minimising the chances of sample contamination. A biosensor is defined by its ability to measure an analyte by converting a biological binding event to tangible analytical data. With evolving manufacturing processes for both LoaDs and biosensors, it is becoming more feasible to embed biosensors within the platform and/or to pair the microfluidic cartridges with low-cost detection systems. This review considers the basics of the centrifugal microfluidics and describes recent developments in common biosensing methods and novel technologies for fluidic control and automation. Finally, an overview of current devices on the market is provided. This review will guide scientists who want to initiate research in LoaD PoC devices as well as providing valuable reference material to researchers active in the field.

scholarly journals Polymer microfluidic devices: an overview of fabrication methods

2017 ◽  
Vol 1 (1) ◽  
pp. 67-79 ◽  
Author(s):  
Raquel O. Rodrigues ◽  
Rui Lima ◽  
Helder T. Gomes ◽  
Adrián M. T. Silva
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Lab On A Chip ◽  
Microfluidic Devices ◽  
Point Of Care Testing ◽  
Standard Methods ◽  
Time Consumption ◽  
Advantages And Disadvantages ◽  
Fundamental Research ◽  
Microfabrication Techniques

The amount of applications associated with microfluidic devices is increasing since the introduction of Lab-on-a-chip devices in the 1990s, especially regarding biomedical and clinical fields. However, in order for this technology to leave the fundamental research and become a day-life technology (e.g., as point-of-care testing), it needs to be disposable and reasonably less expensive. Polymers, due to their several advantages, such as easier microfabrication and low-cost, fill these needs. Several methods are reported regarding microfabrication and, thus, the main aim of the present work is to provide an overview of the most relevant microfabrication techniques found in literature employing polymers, clarifying also the main advantages and disadvantages of each technique and especially considering their cost and time-consumption. Moreover, a future outlook of low-cost microfabrication techniques and standard methods is provided.

Identificación de polaridad de los devanados en un motor trifásico de 6 terminales

2019 ◽  
pp. 13-19
Author(s):  
José Luis Viramontes-Reyna ◽  
Josafat Moreno-Silva ◽  
José Guadalupe Montelongo-Sierra ◽  
Erasmo Velazquez-Leyva
Keyword(s):  
Low Cost ◽  
Voltage Reference ◽  
Three Phase ◽  
Voltage Phase ◽  
The Law ◽  
And Control

This document presents the results obtained from the application of the law of Lens to correctly identify the polarity of the windings in a three-phase motor with 6 exposed terminals, when the corresponding labeling is not in any situation; Prior to identifying the polarity, it should be considered to have the pairs of the three windings located. For the polarity, it is proposed to feed with a voltage of 12 Vrms to one of the windings, which are identified randomly as W1 and W2, where W1 is connected to the voltage phase of 12 Vrms of the signal and W2 to the voltage reference to 0V; by means of voltage induction and considering the law of Lens, the remaining 4 terminals can be identified and labeled as V1, V2, U1 and U2. For this process a microcontroller and control elements with low cost are used.

Restoring and Controlling the Water Pollution of Endangered River in Bangladesh: A Case Study in Pabna City

2020 ◽  
Vol 3 (2) ◽  
pp. 68-81
Author(s):  
Abu Sadath ◽  
Farhana Afroz ◽  
Hosne Ara ◽  
Abdulla-Al Kafy
Keyword(s):  
Water Pollution ◽  
Local Community ◽  
River Flow ◽  
Low Cost ◽  
Design Approach ◽  
Government Officials ◽  
Conservation Plan ◽  
Policy Measures ◽  
And Control ◽  
Riverfront Development

Rivers are the lifeline of Bangladesh economy and serve as the source of water supply, fisheries, irrigation for agriculture, low-cost transport, generate electricity and conserve biodiversity. The Ichamati River situated in Pabna, Bangladesh is also a blessing for the city. However, recently, due to the irregular and unplanned activities adjacent to the riverside, the life, flow and water quality of the river is in a vulnerable condition. This study aims to identify the present status of the Ichamati River and provide an effective design approach and policy measures in restoring the river flow and control water pollution. The data was collected from the questioner surveys, key informant interviews and focus group discussions. Results suggest that several factors such as the construction of an illegal settlement, unplanned waste dumping, disposal of fiscal sludge through sewerage connection, lack of awareness among people regarding the importance of river biodiversity and absence of riverfront development and conservation plan are responsible for water pollution, inconsistent water flow and damaging the life cycle of Ichamati river. The design approach and policy measures were developed based on the perceptions of local community people, experts and government officials. The suggested policy measures will help to restore the flow of the river and reduce the water pollution, and the design approach will ensure the economic benefit of the riverfront development in future.

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