Michael Hooker Microscopy Facility (MHMF.ORG)

Using the Atomic Force Microscope

0.  The System

A Brief Introductions to AFM:

• http://stm2.nrl.navy.mil/how-afm/how-afm.html
• http://www.chembio.uoguelph.ca/educmat/chm729/afm/firstpag.htm
• http://www.nanoscience.com/education/AFM.html

1.  Setup

Tip & cantilever

Tips, cantilever and silicon nitride block are purchased and super glued to a half moon plate.  The half moon plate is magnetically coupled to a tripod and cylindrical translator, which moves the tip assembly over the sample. 

The scan head is rested upside down when the half moon plate with cantilever are placed on the tripod or cylindrical translator.

The scan head itself is also a tripod setup with two manual screws at the back to adjust height and a motorized screw at the front, which is under software control.  It is important to view the video monitor when placing the scanner assembly onto the scanning block.  The scanning block holds the sample on a magnetic disk using double sided tape or super glue. 

or see: http://www.chembio.uoguelph.ca/educmat/chm729/afm/princip.htm

Log onto WinodwsNT4 using a local account name and password.

Start the SPM software.

The correct probe number must be chosen, and the ECU (electronic control unit) powered on.  Default is last used probe, and will be correct unless a different scanner has been installed.

Enable laser.

Steer laser beam onto tip of cantilever.  This is a difficult task.  Beam reflection is hard to follow.

Setup TB mirror angle to zero crossing point

Enable target and setup to non-contact mode

Setup LR mirror angle to zero crossing point

Check TB for minimm

Setup for Tapping (Non Contact) mode scanning

In non-contact window enable Active

Full spectrum

Zoom in using left / right mouse clicks

Choose amplitude, gain

Put red triangle on peak. 

Maneuver sample position.

Lower (raise) back height adjustment screws manually.  Use up/down buttons to adjust front screw.  Want scanner plate to be about horizontal, ie tip to be dangling down slightly.  If angle is up then back block may crash into sample.

Use tip approach to lower assembly.

Look for jump.

Check that displacement is not saturated

Press scan

Don't bump table, move mouse, tap keyboard, etc.

What image develop, and play with leveling

File --> save when done.

2.  Operation

		Copyright 2001-2015  Dr. M. Chua, School of Medicine, University of North Carolina, Chapel Hill, NC 27599
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