Wednesday, October 27, 2010

Some Open Science... um, Science!

We're in the calibration phase of working on the tweezer and I thought people would be interested to see what that entails. There are several steps in the process and we've only just begun. You can check out some of my notes here

I started with signal detection while scanning a stuck microsphere. Nothing complicated there. I made a sample with 1um beads stuck to my glass slide. We have a feedback program that will allow me to move the stage so the laser can pass through the bead thereby scanning over the bead. Then I move the objective to change the focal plane and scan again. I do this a lot of times and try to determine where the best location for trapping is.
DOG signal.
You can check out the preliminary data here (best viewed in Chrome or IE). The graphs on that page are called the Derivative of Gaussian signal (or DOG for short) and is what you get when the trap moves across a bead. From there I take a couple of nice data sets and import the data into Excel and graph the linear region of each curve (right through the symmetric region). I fit that curve and extra the sensitivity parameters for the trap.

For now the graphs aren't as clean as we would like because of noise issues in the lab. Once that gets taken care of I will do the experiment again and then run some power spectrum analysis with free floating beads. More on that to come.

No comments:

Related Posts with Thumbnails