Difference between revisions of "Droplet Mixing Using Electrically Tunable Superhydrophobic Nanostructured Surfaces"

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(New page: '''Soft Matter Key Words''' Nanostructures, DNA hybridization, superhydrophobic surface, droplet mixing '''Context''' Recently there has been a lot of effort towards creating lab-on-a...)
 
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The group performs mixing by using electrowetting techniques. First, a superhydrophopic surface is fabricated by etching a lattice of nanoscale pillars into a silicon surface. A layer of thermal oxide was grown on top of these pillars, and then a layer of fluorocarbons was deposited on top of that. The fluorocarbon layer makes the surface extremely hydrophobic, yielding a contact angle as high as 150-160 degrees between a water droplet and the surface. A droplet of water placed on top of this surface sits on top of the pillars to minimize the contact area, as in the right hand side of the cartoon in figure a.

Revision as of 22:11, 11 September 2010

Soft Matter Key Words


Nanostructures, DNA hybridization, superhydrophobic surface, droplet mixing

Context


Recently there has been a lot of effort towards creating lab-on-a-chip devices. For a lab-on-a-chip device to be effective, it must be able to perform biological assays. Cost, portability, and time are all factors that come into play when designing a lab-on-a-chip device. Most of these devices deal with very small quantities of samples, on the order of a few microliters of fluid. Many biological assays, such as DNA hybridization, require effective mixing of the sample in order to speed up a process. In this vein, there has been a push towards effective mixing techniques for these devices. This papers discusses one method developed in the lab.

Design

Aizenberg droplet.png

The group performs mixing by using electrowetting techniques. First, a superhydrophopic surface is fabricated by etching a lattice of nanoscale pillars into a silicon surface. A layer of thermal oxide was grown on top of these pillars, and then a layer of fluorocarbons was deposited on top of that. The fluorocarbon layer makes the surface extremely hydrophobic, yielding a contact angle as high as 150-160 degrees between a water droplet and the surface. A droplet of water placed on top of this surface sits on top of the pillars to minimize the contact area, as in the right hand side of the cartoon in figure a.