User:Grisafi95/sandbox

Critique an Article

Article: Sicily

Hello,

I would like to say a few suggestions to improve this article. A good amount of sections are missing citations for historical information and facts about geography (ex. length of rivers table). Under the "Flora and fauna," although it describes the land as being heavily agricultural, the only flora object mentioned is a chestnut tree and it would be nice to add other species of plants to the list. It might be nice to update information that was posted years ago with a newer source (such as the current president of Sicily) to show the article is being reviewed constantly and is up to date. Along with that, information on the status of the bridge that was proposed to be built would benefit from updated information as well. Just a quick search showed the estimate price for the project went up and that another concern for building it was because of earthquakes. Grisafi95 (talk) 04:14, 22 May 2017 (UTC)

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Digital microfluidics can be used together with analytical analysis procedures such as mass spectrometry, colorimetry, electrochemical, and electrochemiluminescense.

Draft Article Before Peer-Review

(Under Basics section)

EWOD depends on electrode configuration, the use of dielectric material and its thickness, and applied voltage. (2) Modifications can be implanted to the basic design structure. One example of this is fabricating electrochemiluminescence detectors into the ITO layer to aid in the detection of luminophores in droplets. (1) In general, different materials may also be used such as PDMS replacing the use of glass. (3) To prevent evaporation and to reduce surface contamination, a closed two-plate system may be used by the addition of oil, or other substances, between the two plates. (4,6)

(Under Working Principle section)

Droplets are formed using the surface tension properties of liquid. For example, water placed on a hydrophobic surface will lower its contact with the surface by creating drops whose contact angle with the substrate will increase as the hydrophobicity increases. In other words, this changes the ability for the liquid to spread and ‘wet’ the surface. (5) Change in contact angle, and therefore wetting, is regulated by the Young-Lipmann equation. (2) In some cases it is possible to control the hydrophobicity of the substrate by using electrical fields. This is referred to as "Electrowetting On Dielectric" or EWOD.[3][4] In thin layers of Teflon AF, FluoroPel V- polymer or CYTOP, for example, when no field is applied, the surface will remain extremely hydrophobic and a liquid droplet will try to 'stay away' from the surface, resulting in a droplet with a greater contact angle. When a field is applied, a polarized hydrophilic surface is created. The water droplet then tries to 'get closer' to the surface, causing the contact angle to decrease and resulting in much more spread out droplet. By controlling the localization of this polarization, it is possible to control the displacement of the droplet by creating an interfacial tension gradient on the microfluidic device. (4)

Final Draft on Wikipedia

Under Basics Section

Digital microfluidics is one of various embodiments of EWOD-based microfluidic biochips, investigated first by Cytonix in 1987 [1] and subsequently commercialized by Advanced Liquid Logic. A digital microfluidic (DMF) device set-up depends on the substrates used, the electrodes, the configuration of those electrodes, the use of a dielectric material, the thickness of that dielectric material, the hydrophobic layers, and the applied voltage.[1] [2]

A common substrate used is this type of system is glass. Depending if the system is open or closed, there would be either one or two layers of glass. The bottom layer of the device contains a patterned array of individually controllable electrodes. [1] When looking at a closed system, there is usually a continuous ground electrode found through the top layer made usually of indium tin oxide (ITO). The dielectric layer is found around the electrodes in the bottom layer of the device and is important for building up charges and electrical field gradients on the device. [2] A hydrophobic layer is applied to the top layer of the system to decrease the surface energy where the droplet will actually we be in contact with.[2] The applied voltage activates the electrodes and allows changes in the wettability of droplet on the device’s surface. In order to move a droplet, a control voltage is applied to an electrode adjacent to the droplet, and at the same time, the electrode just under the droplet is deactivated. By varying the electric potential along a linear array of electrodes, electrowetting can be used to move droplets along this line of electrodes.[3]

Modifications to this foundation can also be fabricated into the basic design structure. One example of this is the addition of electrochemiluminescence detectors within the indium tin oxide layer (the ground electrode in a closed system) which aid in the detection of luminophores in droplets.[4] In general, different materials may also be used to replace basic components of a DMF system such as the use of PDMS instead of glass for the substrate.[5] Liquid materials can  be added, such as oil or another substance, to a closed system to prevent evaporation of materials and decrease surface contamination.[3][6] Also, DMF systems can be compatible with ionic liquid droplets with the use of an oil in a closed device or with the use of a catena (a suspended wire) over an open DMF device.[6]

Under Working Principle

Droplets are formed using the surface tension properties of a liquid. For example, water placed on a hydrophobic surface such as wax paper will form spherical droplets to minimize its contact with the surface. Differences in surface hydrophobicity affect a liquid’s ability to spread and ‘wet’ a surface by changing the contact angle. As the hydrophobicity of a surface increases, the contact angle increases, and the ability of the droplet to wet the surface decreases. The change in contact angle, and therefore wetting, is regulated by the Young-Lipmann equation.

$\cos(\theta )=\cos(\theta ){_{0}}+{\frac {\varepsilon {_{0}}\varepsilon {_{r}}V^{2}}{{2\gamma }d}}$

where θ= contact angle with no voltage; θo= contact angles with applied voltage; εr=relative permittivity of the dielectric; ε0=permittivity of free space; V= applied voltage; γ= liquid/filler media surface tension; d= dielectric thickness.

In some cases, the hydrophobicity of a substrate can be controlled by using electrical fields. This refers to the phenomenon Electrowetting On dielectric (EWOD).[3][4] For example, when no electric field is applied to an electrode, the surface will remain hydrophobic and a liquid droplet will form a more spherical droplet with a greater contact angle. When an electric field is applied, a polarized hydrophilic surface is created. The water droplet then becomes flattened and the contact angle decreases. By controlling the localization of this polarization, we can create an interfacial tension gradient that allows controlled displacement of the droplet across the surface of the DMF device.

Reflective Essay

1) I worked on the Digital Microfluidics Wikipedia page. This article was existing but had very limiting information on the page and, to me, some headers were confusing with what was written under those sections. It was unorganized and had hardly any citations.

2) My major contributions to this wikipedia was drawing 3 diagrams that are based off the basic structure of a microfluidic device with a little description for each drawing. I added information to both the basic and working principle sections. For the basic section I took the information from the implementation section and used previous information and new information to talk about the different parts of a DMF device and modifications you can do. Under working principle, I edited the old information in the working principle, added citations to that information along with the young-lipmann equation, and a bit more information.

3) I tried to incorporate all the suggestions that I received. It seems it was confusing that I used a different color to show the changes that I written over what was originally written. What was nice though people edited information originally from the article that I couldn’t exactly find a way to make it sound better on my own. I only received feedback from the peer reviews we did in the email as well as the “talk page” our digital microfluidics group created. Specific things I changed are:

-the way I said things so I don't use the word "you" in my writing and changed terms that were originally there so they sound more scientific

-I got a comment that I should list materials in the basic section I worked on so I took information from the implementation section and added it in there because it seemed to be a better fit (I asked my group if they thought the same thing)

-I labeled what things stood for in my diagrams

-I added in the young-Lippmann equation since there was no wiki page on that to link it to

-I reworded things I said and tried to transition my ideas better together

4) I feel this assignment was somewhat valuable to my learning. Finding and reading through articles I thought was the most valuable experience. You had to efficiently look through each article to find if it was useful to your topic. It was also interesting to research further into a topic involved in class. To me, it was hard to critically review peer paragraphs because I felt I wasn’t very qualified and what if I said was wrong. Also, since my sections were general and not very specific, I found it hard to think of what to add to those sections with the information that was already there.  I think my section will be valuable to Wikipedia though. It sums up the basics of digital microfluidics and I feel the diagrams I’ve made will be helpful to others to visualize what these systems look like. To improve this assignment, I feel it might be helpful to have quick group meetings every week that wouldn’t last that long (~5-10 min) so that everyone checks in on what they’re doing and if they have any ideas on how to do things and people may feel more accountable to have their things done. Also, it would be helpful to look at a final wikipedia project to see what yours should be modeled after such as seeing Jing's sandbox.

Images Created

References