User:Ulrilee/sandbox

== Initial planning for my article == I will edit Jing's open microfluidics overview and more information on paper based and thread based microfluidics as well as a disadvantages to open microfluidics paragraph.

Article Evaluation
Point-of-care testing

Reflection Paragraph
The point-of-care testing article lacks neutrality. There is no mention of the negative aspects or shortcomings of point of care devices. The article needs significantly more citations especially because the topic is medical in nature. In addition, statements of length of time need to be adjusted to reflect accurate dates. One sentence refers to the last decade as a metric of time, but it must be taken into consideration the future of the article. If people read this article in 20 years, the last decade will not be an accurate representation of what the article is referring to. The Talk page discusses the issue of neutrality as well as a plagiarism offense due to copying and pasting from another source. The copy and pasted portions are from unreliable and biased sources such as the home page of a diagnostic company's website. Additionally it was mentioned the article could benefit from a history section where the major contributions to point of care testing devices were give to provide context.

Text I posed to the article's talk page
Statements of length of time need to be adjusted to reflect accurate dates. One sentence refers to the last decade as a metric of time, but it must be taken into consideration the future of the article. If people read this article in 20 years, the last decade will not be an accurate representation of what the article is referring to and will therefore be out of date. ~Ulrilee

Add to an article
Original:

Major benefits are obtained when the output of a POCT device is made available immediately within an electronic medical record. Results can be shared instantaneously with all members of the medical team through the software interface enhancing communication by decreasing turn around time (TAT). A reduction in morbidity and mortality has been associated with goal-directed therapy (GDT) techniques when used in conjunction with POCT and the electronic medical record.

Edited:

The coupling of POC devices and electronic medical records enable test results to be shared instantly with care providers. The use of mobile devices in the health care setting also enable the health care provider to quickly access patient test results sent from a POC device. A reduction in morbidity and mortality has been associated with such rapid turn around times from a study using the i-STAT to analyze blood lactate levels after congenital heart surgery.

Paper based microfluidics
cheap, accessible, environmentally friendly

multiple pore sizes and types of paper available

high limit of detection

Thread based microfluidics
off shoot from paper based microfluidics

3D structural capabilities

3D tissue engineering and analyte analysis

multiple types of thread availabe

Disadvantages of open microfluidics
evaporation

contamination

limited flow rate

Article I emailed for peer review
Open microfluidics (section in main article Microfluidics)

In open microfluidics, at least one boundary of a system is removed, exposing the system to air or another interface (i.e. liquid).[1][2][3][4] Advantages of open microfluidics include ease of accessibility such as intervention to the flowing liquid in the system for open-channels, larger liquid-gas surface area, and minimization of bubble formation.[1][2][4] Another advantage of open system microfluidics is fluid flow can be surface-tension driven, which eliminates the need for external pumping methods.[5] The devices are also easy and cheap to fabricate by milling, thermoforming, or embossing. In addition, open microfluidics eliminates the need to glue or bond a cover for devices which could be detrimental for capillary flows. Examples of open microfluidics include open-channel microfluidics, rail-based microfluidics, paper-based, and thread-based microfluidics.[1][6]

Open microfluidics (own page)

Microfluidics refers to flow of fluid in channels or networks where at least one of the dimensions is on the micron scale.[1][9] In open microfluidics, also referred to as open-surface microfluidics or open-space microfluidics, one of the boundaries of a system is removed, and the system is exposed to air or another interface such as liquid. [1][2][3][4]

Advantages

One of the main advantages of open microfluidics is ease of accessibility which enables intervention (i.e. for adding or removing reagents) to the flowing liquid in the system. Open channels also allow gelling of polymeric liquids by adding a gelling agent on top of the flow. Open microfluidics also allows simplicity of fabrication eliminating the need to bond surfaces. When one of the boundaries of a system is removed, a larger liquid-gas interface results, which enables liquid-gas reactions.[1][5] Open microfluidic devices enable better optical observation when optical transparency is important or elimination of autofluorescence of the surface material. Further, open systems minimize and sometimes eliminate bubble formation, a common problem in closed system.[1]

In closed system microfluidics, the flow in the channels is driven by pressure via pumps (syringe pumps), valves (trigger valves) or electrical field.[10] Conversely to fluid flow via active pumping, open system microfluidics enable surface-tension driven flow in channels thereby eliminating the need of external pumping methods. For example, some open microfluidic devices consist of a reservoir port and pumping port that can be filled with fluid using a pipette.[5] Eliminating external pumping requirements lowers cost and enables device use in all laboratories with pipettes.[5]

Disadvantages

Some drawbacks of open microfluidics include evaporation, sterility, and limited flow rate. (crossref delamarche for evap) Open systems are susceptible to evaporation, especially when using volatile fluids, evaporation can greatly affect readouts because microscale volumes of fluid are used. Additionally, sterility in open systems is more difficult than in closed systems. Cell culture and other methods where contamination is a concern must be carefully performed to prevent contamination. Lastly, open systems have limited flow rate. Closed channels can withstand fluid flow pressures, but open channels are limited to flow rates that will not cause fluid to spill out of the designated areas.

Types of open microfluidics

Open microfluidics can be categorized into various subsets. Some examples of these subsets include open-channel microfluidics, paper-based, and thread-based microfluidics.[1][6]]

Open-channel microfluidics

In open-channel microfluidics, the surface tension-driven capillary flow that occurs can be spontaneous capillary flow (SCF).[1] In SCF, capillary flow occurs spontaneously when the Laplace pressure at the front of the fluid is negative and the pressure of the bulk fluid is nearly zero and the difference in pressure causes the fluid to flow in the channel. [1][5] The geometry of a channel and contact angle (θ) of fluids on the surface of the channel can be used to predict SCF flow in a channel by the equation:[1][6]

pf/pw < cos(θ)

where pf is the free perimeter of the channel (i.e., the interface exposed to air or liquid), pw is the wetted perimeter (i.e., the walls of the surrounding channel), and θ is the contact angle of the fluid on the device material.[1][6]

Surface wettability and surface modification control the flow and confine the liquid in the channel.[3] One drawback of open channels is the potential for overflow which often occurs when an inlet pressure is applied. For example, pipetting a big droplet can cause a convex surface in the reservoir creating an upstream pressure (Laplace) that may cause overflow. In the case of SCF, overflow is seldom. but can be prevented if the carrier fluid preferentially wets the walls of the channels.

Paper-based microfluidics (link to Paige and Julian’s wikipage)

Paper-based microfluidics utilizes the wicking ability of paper for functional readouts. Paper-based microfluidics is an attractive method because paper is cheap, easily accessible, and has a low environmental impact. Paper is also versatile because it is available in various thicknesses, pore sizes, and is modifiable. Coatings such as wax have been used to change the wicking power of the paper and to guide flow into designated areas. In some cases, wax has been used to create boundaries on the paper, effectively directing and confining the flow of the fluid to a specific area on the paper. The application of paper as a diagnostic tool has proven to be powerful because it has successfully been used to detect glucose levels, bacteria, viruses, and other small molecules in whole blood. Cell culture within paper have also been developed. Lateral flow immunoassays, such as those used in pregnancy tests, are just one example of the application of paper for point of care diagnostics.

Thread-based microfluidics

Thread-based microfluidics, an offshoot from paper-based microfluidics, utilizes the same capillary based wicking capabilities. The threads are versatile because they can be weaved to form different patterns. Additionally, two or more threads can be knotted together to mix multiple reagents. Threads are also relatively strong and difficult to break from handling which increases its’ stability overtime and during transportation. Thread based microfluidics has been used for 3D tissue engineering and potassium analysis. ,

Applications

Like many microfluidic technologies, open system microfluidics have been applied to nanotechnology, biotechnology, fuel cells, and point of care (POC) testing.[1][12][4] For cell-based studies, open-channel microfluidics devices enable access to cells for single cell probing within the channel.[13] Other applications include capillary gel electrophoresis, water-in-oil emulsions, and biosensors for POC systems.[2][3][11] Suspended microfluidic devices have been used to study cellular diffusion and migration of cancer cells. (crossref Casavant) Suspended and rail-based microfluidics have been used for micropatterning and studying cell communication. [1]

Revised article after peer review
Open microfluidics (section in main article Microfluidics)

In open microfluidics, at least one boundary of the system is removed, exposing the fluid to air or another interface (i.e. liquid). Advantages of open microfluidics include accessibility  to the flowing liquid for intervention, larger liquid-gas surface area, and minimized bubble formation. Another advantage of open system microfluidics is surface-tension driven fluid flow, which eliminates the need for external pumping methods such as peristaltic or syringe pumps. Open microfluidic devices are also easy and cheap to fabricate by milling, thermoforming, and hot embossing. In addition, open microfluidics eliminates the need to glue or bond a cover for devices which could be detrimental for capillary flows. Examples of open microfluidics include open-channel microfluidics, rail-based microfluidics, paper-based, and thread-based microfluidics Disadvantages include susceptibility to evaporation, contamination, and limited flow rate.

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Open microfluidics (own page)

Microfluidics refers to flow of fluid in channels or networks where at least one of the dimensions is on the micron scale   In open microfluidics, also referred to as open surface microfluidics or open-space microfluidics, at least one boundary confining the fluid flow of a system is removed, exposing the fluid to air or another interface such as a second fluid.

Types of open microfluidics

Open microfluidics can be categorized into various subsets. Some examples of these subsets include open-channel microfluidics, paper-based, and thread-based microfluidics.

Open-channel microfluidics

In open-channel microfluidics, the surface tension-driven capillary flow that occurs can be spontaneous capillary flow (SCF). In SCF, capillary flow occurs spontaneously when the Laplace pressure at the front of the fluid is negative and the pressure of the bulk fluid is nearly zero and the difference in pressure causes the fluid to flow in the channel. The geometry of a channel and contact angle (θ) of fluids on the surface of the channel can be used to predict SCF flow in a channel by the equation:

pf/pw < cos(θ)

where pf is the free perimeter of the channel (i.e., the interface not in contact with the channel wall), pw is the wetted perimeter (i.e., the walls in contact with the fluid), and θ is the contact angle of the fluid on the material of the device.

Surface modification can increase or decrease surface wettability of a material resulting in a change in flow rate. One drawback of open channels is the potential for overflow which often occurs when an inlet pressure is applied. For example, pipetting a big droplet can cause a convex surface in the reservoir creating an upstream pressure (Laplace) that may cause overflow. (Ref) In the case of SCF, overflow is seldom. but can be prevented if the carrier fluid preferentially wets the walls of the channels.

Paper-based microfluidics (link to Paige and Julian’s wikipage)

Paper-based microfluidics utilizes the wicking ability of paper for functional readouts. Paper-based microfluidics is an attractive method because paper is cheap, easily accessible, and has a low environmental impact. Paper is also versatile because it is available in various thicknesses and pore sizes. Coatings such as wax have been used to affect the wicking power of the paper and guide flow. In some cases, dissolvable barriers have been used to create boundaries on the paper and control the fluid flow. The application of paper as a diagnostic tool has proven to be powerful because it has successfully been used to detect glucose levels, bacteria, viruses, and other small molecules in whole blood. Cell culture methods within paper have also been developed. Lateral flow immunoassays, such as those used in pregnancy tests, are just one example of the application of paper for point of care diagnostics. Disadvantages include difficulty of fluid retention and high limits of detection.

Thread-based microfluidics

Thread-based microfluidics, an offshoot from paper-based microfluidics, utilizes the same capillary based wicking capabilities. Common thread materials include nitrocellulose, rayon, nylon, hemp, wool, polyester, and silk. Threads are versatile because they can be weaved to form specific patterns. Additionally, two or more threads can converge together in a knot bringing two separate ‘streams’ of fluid together as a reagent mixing method. Threads are also relatively strong and difficult to break from handling which makes them stable overtime and easy to transport. Thread-based microfluidics has been applied to 3D tissue engineering and analyte analysis.

Advantages

One of the main advantages of open microfluidics is ease of accessibility which enables intervention (i.e. for adding or removing reagents) to the flowing liquid in the system. Open channels also allow polymeric liquids to gel when a gelling agent is added on top of the flow. (Ref) Open microfluidics also allows simplicity of fabrication eliminating the need to bond surfaces. When one of the boundaries of a system is removed, a larger liquid-gas interface results, which enables liquid-gas reactions. Open microfluidic devices enable better optical transparency because at least one side of the system is not covered by the material which can reduce autofluorescence during imaging. Further, open systems minimize and sometimes eliminate bubble formation, a common problem in closed system.

In closed system microfluidics, the flow in the channels is driven by pressure via pumps (syringe pumps), valves (trigger valves) or electrical field. Conversely to fluid flow via active pumping, open system microfluidics enable surface-tension driven flow in channels thereby eliminating the need of external pumping methods. For example, some open microfluidic devices consist of a reservoir port and pumping port that can be filled with fluid using a pipette. Eliminating external pumping requirements lowers cost and enables device use in all laboratories with pipettes.

Disadvantages

Some drawbacks of open microfluidics include evaporation, contamination, and limited flow rate. Open systems are susceptible to evaporation which can greatly affect readouts when fluid volumes are on the microscale. Additionally, due to the nature of open systems, they are more susceptible to contamination than closed systems. Cell culture and other methods where contamination or small particulates are a concern must be carefully performed to prevent contamination. Lastly, open systems have a limited flow rate. Closed channels can withstand fluid flow pressures, but open channels are limited to flow rates that will not cause fluid to spill out of the designated areas. Increasing the wettability of an open channel can increase the flow rate.

Applications

Like many microfluidic technologies, open system microfluidics have been applied to nanotechnology, biotechnology, fuel cells, and point of care (POC) testing. For cell-based studies, open-channel microfluidic devices enable access to cells for single cell probing within the channel. Other applications include capillary gel electrophoresis, water-in-oil emulsions, and biosensors for POC systems. Suspended microfluidic devices, open microfluidic devices where the floor of the device is removed, have been used to study cellular diffusion and migration of cancer cells. Suspended and rail-based microfluidics have been used for micropatterning and studying cell communication.

Reflective essay
1.     What article did you work on? Was this a new article or an existing article?

I worked on adding to the open microfluidics Wikipedia article originally started by Jing Lee.

2.     Summarize your main contributions in 3-4 sentences or bullet points.

·     Added paragraphs on

o  Disadvantages of open microfluidics

o  Paper based microfluidics

o  Thread based microfluidics

·     Compiled and edited Jing’s work with mine for flow (article consolidator)

3.     How did you respond to suggestions from peer reviewers? Please list specific changes in 3-5 sentences or bullet points. Also indicate if you used the Wikipedia content expert or received feedback from other Wikipedians outside the course.

·     Elaborating on suspended microfluidics by including definition

·     Added disadvantages to paper based microfluidics: high limits of detection and fluid retention

·     Added disadvantages of open microfluidics to the paragraph for the microfluidics main page: evaporation, contamination, and limited flow rates

·     Rearranged paragraph order to introduce types of open microfluidics before overall advantages and disadvantages

I did not receive feedback from Wikipedians outside of this course or use the content expert.

4.     Reflect on the following questions in a short paragraph: Was this assignment valuable to your learning (of course material, research/literature review skills, ability to critically evaluate peers, etc.) - why or why not? Do you think your article will be valuable to Wikipedia readers? How could this assignment be improved in the future? [You will not lose points for negative comments; please be honest in your critiques of this assignment to improve the course for future years.]

This assignment was useful for helping me recognize when I or others am writing in a biased manner. I am now more aware and cognizant of when papers do not present all sides or perspectives.

I think this article will be useful to Wikipedia readers because the microfluidics field is growing so rapidly and different subsets of microfluidics are also appearing. Open microfluidics is gaining popularity and I have personally found it difficult to quickly find a synopsis of certain types of open microfluidics without reading many papers utilizing the technique. For those who do not have prior knowledge to open microfluidics or work in the open microfluidics field, but want to know a simple definition or common examples it would be difficult to get a quick answer. The open microfluidics article also brings together already known types of microfluidics such as paper based, thread based, and suspended into the open microfluidics subset of microfluidics. A tree type structure breaking down microfluidics would be helpful.

This assignment could be improved if there was less work to do in the sandbox such as adding to an existing article. I didn’t find them helpful to me for writing the final Wikipedia article. It would also be helpful to have a few minutes of class time right before the article rough drafts are due to ask classmates with related topics for some of their references to cross reference with ones in your article.