Thursday, July 2, 2009

A New Skill - SEM Photos

I have recently added a new skill to my arsenal of hot science - the ability to take SEM (scanning electron microscope) pictures. For my non-science people, this is different from a microscope (uses light to see an object) or a profilometer (measures the surface profile of an object by actually touching it). An SEM provides an image of an object by measuring the backscatter of electrons beamed at the surface.

So for my M.S. I designed and built a machine that makes plastic parts, called microfluidic devices (the buzzword is lab-on-a-chip, because these microfluidic devices condense chemical and biological processes onto a tiny plastic chip). These little chips are about an inch by and inch and a half, and the pattern on the chip has dimensions about the size as a human hair.

I took one of the plastic parts that my machine produces and brought it over to the SEM machine, and had a friend show me how to use it. The part has the following pattern on it:

On the actual part, it looks like the following (I can't get a shot of the whole thing at once, unfortunately):

Since I work in a manufacturing lab, I am interested in quality and consistency over large runs of parts. So to test my machine, I make a bunch of parts and measure them all at the same spots on each part. Here are the spots I measure (I really measure eight spots, but these are the important three):

And so I figured I probably want to have pictures of those spots, not just data and x-y-z-coordinates. You need pretty pictures for papers and presentations, you know. :)

So here are pictures of measurement sites 1 and 2:

Although I tried to keep these parts clean, I didn't quite succeed. Note the big black spot on the above picture - whoops. Or here is a square with foreign material in it - possible skin cells, dust, what have you. Next time I will do better at keeping my part clean before I take pictures.

And just for fun, the Swiss flag:

Oh, okay, it's just a fiducial, not the Swiss flag...

Next time I'm putting "Miss Outlier" on the part somewhere so I get my name in teeny tiny letters. :)

1 comment:

  1. ...
    "Next time I'm putting 'Miss Outlier' on the part somewhere so I get my name in teeny tiny letters. :) "


    Most people dream of their name in big bright letters on a Broadway marquee.

    While you dream of 'teeny tiny letters'...


    Nice pictures. I like and appreciate the views.