Today we learned about all the different kinds of microscopes. I don’t remember all of them but the one that made an impression the most was the one where the depth and texture of the sample was determined by a needle being rolled over the surface and a laser being pointed to the top of the needle with a detector at the top absorbing the reflected laser beam. This detector would then form a three dimensional picture showing all the mountains and valleys from the data it collected.
When the scientists explained to us that the point on the needle narrows down to a single atom, I was surprised. Would that atom be able to stay on even with all the pressure and friction from the sample, because no matter how light the pressure is, there still will be pressure, and considering how small the sample and the needle are, the proportion of size to pressure will definitely increase. I was wondering and picturing these things while the teacher went on with the lecture for a while. I didn’t remember till I checked my notes later that it was called the atomic force microscope.
Another topic that interested me was the theory of the quantum confinement. I didn’t understand the first time the teacher explained it, but the video and the pictures they showed later helped a lot. I like how the color of the quantum dots changed as the molecule grew smaller. At first I thought that the color just changed with only the shrinking of the size. The video helped me understand that the quickening movement of the quantum dot in the shrinking molecule contributed to the color change, though I wasn’t sure how.
The lab visits were great too. Most of the microscopes we saw showed the images on the computer screen, and I guess that helps with clarity during research, but I personally like looking through the lenses; it makes it feel more real and live.
http://www.lbl.gov/Science-Articles/Archive/Quantum-Dot-Electronics.html
http://www.nanoscience.com/education/AFM.html
http://mse.iastate.edu/microscopy/ray_diagrams.html
http://mse.iastate.edu/microscopy/vacuum.html
http://mse.iastate.edu/microscopy/source.html
http://mse.iastate.edu/microscopy/beaminteractions.html
