This is a physics related presentation that covers the basics , construction , components and working of an atomic force microscope with examples.

2. EARLY MICROSCOPES

3. HISTORY
• In 1929 Shmalz described Stylus Profiler.
• In 1950 Becker suggested oscillating the probe that approach
contact with surface.
• In 1971 Young described non contact type stylys.
• In 1982 Binning and Rohrer described STM(Scanning
Tunnelling Microscope).
• AFM was invented in 1986 by Binning.

4. ATOMIC FORCE MICROSCOPY
Atomic force microscopy or scanning force microscopy is a very-high-resolution type of
scanning probe microscopy, with demonstrated resolution on the order of fractions of a
nanometer, more than 1000 times better than the optical diffraction limit.
It is an invaluable tool not only to obtain high-resolution topographical images, but also to
determine certain physical properties of specimens, such as their mechanical properties and
composition.
The atomic force microscope (AFM) was developed to overcome a basic drawback with STM
– it can only image conducting or semiconducting surfaces. The AFM has the advantage of
imaging almost any type of surface, including polymers, ceramics, composites, glass, and
biological samples.
Binnig, Quate, and Gerber invented the AFM in 1985. Their original AFM consisted of a
diamond shard attached to a strip of gold foil.

5. THE FIRST ORIGINAL ATOMIC FORCE MICROSCOPE

6. BASIC COMPONENTS
• The basic components of an Atomic
force microscope include :
• Photo-detector and feedback control
• Probe
• Scanner
• Cantilever and tip
• Laser

7. PROBE

8. CANTILEVER

9. SCANNER

10. PHOTO DETECTOR AND FEEDBACK
CONTROL

11. OVERVIEW OF COMPONENTS AND
FUNCTIONS

12. PATHWAY

13. DIFFERENT IMAGING MODES

14. CONTACT MODE EXAMPLE

15. TAPPING MODE

16. NON CONTACT MODE

17. ADVANTAGES DISADVANTAGES
ADVANTAGES AND DISADVANTAGES OF AFM
‣ Easy sample preparation.
‣ Non-destructive imaging.
‣ Accurate height information.
‣ Works in vacuum , air and liquids.
‣ Living systems can be studied.
‣ Sample not required to be conductive.
‣ Polymers , ceramics , glass , metals ,
‣ Limited vertical range.
‣ Limited magnification range.
‣ Highly dependent on AFM
probes.
‣ Tip or sample can be
damaged.

18. APPLICATIONS
A. Digitally images a topographical surface.
B. Determines the roughness of a surface sample or to measure
the thickness of a crystal growth layer.
C. Any sample like ceramic material , human cells or individual
molecules of DNA.
D. In biological applications:
1.Study of unfolding particles
2.Imagining of biomolecules
3.Force measurements in real solvent environments
4.Antibody-Antigen Binding studies
5.Ligand-Receptor Binding studies
6.Binding Forces of complimentary DNA strands

20. SUMMARY
• AFM stands for Atomic Force Microscopy.
• It works by scanning a probe over the sample surface, building up
a map of the height or topography of the surface as it goes along.
• AFM microscopy is different from other microscopes as it
physically feels the sample’s surface with a sharp probe , building
up a map of the height of sample’s surface.
• It provides single atomic level structure so provides high resolution.
• It doesn’t need focusing , illumination , depth of field.

21. • Main components of the AFM instrument include:
• Microscope stage : Moving AFM tip , Sample holder , Force
sensor
• Control electronics : Optical microscope , Vibration controller
• Computer : The control electronics usually takes the form of a
large box interfaced to both the microscope stage and the
computer.

22. AFM has 3 basic modes of operation:
1. Contact mode : Strong , Repulsive
• High Resolution Images
• Fastest of all the topographic modes.
• Sensitive to the nature of sample.

23. 2. Non-Contact Mode : Weak , Attractive
• Oscillating modes can measure images with a small
probe-sample force.
3. Tapping Mode : Strong , Repulsive
• No Capillary effect.
• Amplitude signals are used in feedback.
• Used for imaging in air.