investigating the small it is necessary for scientists to make observations in their daily work. but...
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Investigating the small
It is necessary for scientists to make observations in their daily work. But what if their research occurs on a scale that is not visible to the naked eye?
This presentation will introduce you to four instruments which aid scientists for this type of research.
Nanospectrometer
How it works: This instrument uses light interference maxima and minima to measure thicknesses.
Resolution, size, and cost
Resolution is on the order of 10^-10 (Angstroms)
Fits on a table top
Approximately $10K
Scanning Electron Microscope
How it works: An electron beam scans over a sample that creates various signals made of emitted electrons off the surface. This allows for an image to form and magnifies the specimen.
Resolution, size, and cost
Features observed on an SEM are as small as 1-50 nanometers
The size of the instrument itself is about 3x5 ft.
Expect to pay between $100K-$300K for this instrument
Atomic Force Microscope
How it works: A sharp tip touches a sample and forces between the atoms in the sample affect a lever on the tip. This creates a topographical map image for the user.
Resolution, size, and cost
Vertically, this instrument can “see” down to 0.1 x 10^-10 meters! Laterally, it can “see” 1 nanometer.
The AFM fits on a table top
This instrument can be obtained at $65K-$200K
Optical microscope
You have probably used this instrument before. White light is used to illuminate a sample and lenses magnify the sample.
Resolution, size, and cost
Microscopes, like the name implies, “see” down to 0.2 micrometers.
The size ranges from pocket size to a large table top
$5-$5K
Images used
1. Ant. www.sciencemuseum.org.uk/. ../section4/sem.asp
2. Termite. alfa.ist.utl.pt/~cvrm/ staff/vramos/SIP05.html
3. Blood cell. history.nasa.gov/ SP-368/s3ch3.htm
4. SEM Diagram. www.weizmann.ac.il/ home/garty/scanning_electr...
5. SEM. darkwing.uoregon.edu/ ~oimb/equip.htm
6. http://www.sciencemuseum.org.uk/on-line/electron/images/ant.jpg
7. AFM Diagram. http://www.almaden.ibm.com/vis/models/images/afm.gif
8. AFM pic. www1.cems.umn.edu/research/ frisbie/Dimension3...
9. chromium dots. http://physics.nist.gov/Divisions/Div841/Gp3/Projects/Atom/images/nanodots.gif
10. light microscope. http://www.cas.muohio.edu/~mbi-ws/microscopes/images/LightMicroscope.GIF
11. Nanospectrometer. http://www.thtlab.t.u-tokyo.ac.jp/MEMS_Equipment/NanoSpec.jpg
12. plant cell. www.biologie.uni-hamburg.de/ b-online/e04/04a.htm
13. thin film colors . http://electron9.phys.utk.edu/phys136d/modules/m9/images/colors.jpg
I14. nterference diagram. newton.ex.ac.uk/.../ images/thin_film1.jpg
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