Chemical Forums
General Forums => Generic Discussion => Topic started by: Mitch on January 13, 2007, 11:14:06 PM
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My research has recently involved the process of spin coating, and being in a nuclear chemistry group we of course don't have a spin-coater lying around. So, I've been hiking up the hill to use the Somorjai group (http://www.cchem.berkeley.edu/gasgrp/)'s spin-coater. This past week I decided I wanted my own spin-coater and so I set about making my own. The working model is shown below.
(http://blog.chemicalforums.com/blog-spincoaterdark.jpg)
Spin-Coater in the Dark: Lights are turned off for more dramatic effect.
If you're going to start making your own lab equipment you might as well trick out the new hardware. In that spirit, my spin coater has 3 light emitting diodes: a green one, a red one, and a blue one. I can vary the revolution per minute from ~500rpm to ~2500rpm by varying the voltage I supply to the spin coater. The sample is mounted in the center and is stuck to the spin coater by Velcro, this can be more easily seen in the next photo.
(http://blog.chemicalforums.com/blog-spincoaterstop.jpg)
Spin Coater Close Up
As can also be seen in the photo, my spin coater is just a regular pc fan I bought at CompUSA this past Wednesday. I monitor the speed of the spin coater with a laser mounted above the spin-coater that shines through the fan's blades and strikes one of our group's alpha detectors. The nice thing about the alpha detector is that I don't even have to supply any power to it. There is enough current generated, I presume by the photoelectric effect, to carry a signal to an oscilloscope which I can use to monitor the fan's speed. A picture of the laser, which is my boss's laser pointer he uses for talks, is seen in the next photo at the top of our group's only non-radioactive chemistry hood.
(http://blog.chemicalforums.com/blog-spincoaterhood.jpg)
Spin-Coater in the Hood
It took me 2 days to build my spin coater, Wednesday and Thursday, and one more day to make sure it calibrates properly, Friday. The total amount in extra costs was $20 for the spin-coater(pc fan) all the rest of the equipment we had lying around.
Now what other lab equipment could use some LEDs? Hmmm....
Note 1: Paper that first got me interested in using a pc fan: Spin-Coating of Polystyrene Thin Films as an Advanced Undergraduate Experiment (http://www.jce.divched.org/Journal/Issues/2003/Jul/abs806.html) by Mriganka Chakraborty, Devasish Chowdhury, and Arun Chattopadhyay
Mitch
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Another alternative for a ghetto spincoater: old centrifuge. ;)
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Jeese, reading all of Mitch's posts about what he does, it makes being a graduate student sound like fun. :)
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our group's only non-radioactive chemistry hood
That does just sound cool.
Nice job making this so inexpensively! Tricked it out is even cooler.
P.S. I'd be facinated to see any pictures of what your group has in all the other fume hoods.
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?*?: I don't know if it is ghetto... I like to call it TOSCA (Tricked-Out Spin Coating Apparatus)
constant thinker: Grad school is not fun, it is a common misconception though.
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O, I know it's not fun, but what you've talked about tends to add to the fun misconception. I'll be experiencing grad school sooner or later.
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?*?: I don't know if it is ghetto... I like to call it TOSCA (Tricked-Out Spin Coating Apparatus)
Yours isn't ghetto, mine is. Yours is super awesome! Glowing lights and pretty colors? What's not to like?