By: Jorge Simmonds

1
The Basics of the AFM

• By Jorge Simmonds
• Advisor Ron Sabo
• April 27th, 2005

2
Overview

• What is an AFM?
• How does it work?
• Typical AFM Curves
• Application to Samples
• Questions

3
What is an AFM?

• Atomic Force Microscope
• Does not use lenses
• Measure local property with a probe
• Height
• Optical Absorption
• Magnetism

4
Sample Probes
5
How does an AFM work?

• Measures attractive or repulsive forces between
  tip and sample
• Detection apparatus measures the vertical
  deflection for height
• Can achieve resolution of up to 10 pm
• Unlike electron microscopes, can measure samples
  in air and liquid

6
How does an AFM work?
AFM capabilities include measuring topography,
surface energy, and elasticity of samples at the
nanometer, even molecular scale.
7
Makeup of the AFM
8
Typical AFM Force Curves
Far from surface
1
Attraction to surface
2
Cantilever bends as pushed into surface
3
4
Pull-off
9
What Next?

• Choose Sample
• Recycled paper
• Calibrate Machine
• Cantilever
• Laser alignment
• Results!!

10
AFM Adhesion Mapping

• A 10um x 10um force volume scan of a recycled
  Kraft sheet.
• The 3D shape represents the topography, and the
  surface color-scale represents the adhesion
  between the sheet and a hydrophobic tip.
• Large data sets can now be generated to increase
  confidence of the variability studies

11
Summary

• What an AFM is and how it works?
• Typical AFM Curves
• Applications

12

• Questions??