2. Atomic Force Microscopy • AFM is a technique to obtain the topology of samples at a very high resolution. • To acquire an image, the AFM raster-scans the probe over a small area of the sample

3. Cantilever Tip http://www.nanoscience.com/products/afm/afm-probes/ http://artsci.ucla.edu/BlueMorph/research/AFM1.jpg

4. Atomic Force Microscopy (AFM) http://pharm.virginia.edu/AFM.html

5. How Does AFM Work? • AFMs operate by measuring force between a probe and the sample • AFMs measure the vertical and lateral deflections of the cantilever by using the optical lever. • The optical lever operates by reflecting a laser beam off the cantilever. • The reflected laser beam strikes a position-sensitive photo-detector consisting of four-segment photo-detector. • Plotting the laser deflection against the tip position on the sample surface creates a topology of the surface

6. Wafer of AFM Tips http://www.nanoscience.com/products/afm/afm-probes/

7. Nanosurf® EasyScan 2 AFM AFM techniques are useful for investigating the surfaces and characteristics of different materials down to nanometer detail.

8. Applications • Chemistry (Lithography by Local Oxidation of Titanium) • Coating ( Airplane Wing Coating) • Life Science (Tooth Implant - morphology study) • Material Science (Stainless steel - Metrology of indentations) • Microstructure ( CD, DVD, Blu-ray) • Physics (Atomic structures) • Semiconductor (Roughness of solar cell layers) • http://www.nanosurf.com/index.cfm?content=04022009Z

9. Modes of operation • Contact - the probe will maintain continuous contact with the surface • Non-contact (adhesion) - this method utilizes the attractive forces acting on the probe. Attractive force causes the probe to deflect. • Tapping – the cantilever is used as a harmonic oscillator with a resonance frequency