In the normal contact mode, the tip is mounted at the end of a delicate flexible cantilever which is deflected as the tip is rastered over the surface. The deflection is measured using a laser reflected off the back of cantilever and its movement monitored by a quadrant of photocells. In this mode, the tip also suffers drag due to friction which causes the cantilever to twist as well as bend, thereby enabling both the frictional force and topography to be monitored.

By oscillating the cantilever at its resonant frequency and measuring how this changes when influenced by the attractive force as the tip repeatedly taps the surface, a non-contact mode becomes available for topographical imaging where tip wear is greatly reduced.

There are many variants of AFM which are all capable of imaging features that are too small to be seen in conventional optical microscopes and so normally require SEM analysis. AFM however can be carried out in air or under liquids with minimal sample preparation and where provision of topographical measurements such as roughness parameters is facilitated.

• Imaging sub-micron features at nm resolution
• Quantitative topographical measurements
• Relative hardness imaging
• Friction distribution imaging.

Typical Applications

• Surface roughness measurements
• Nanotechnology
• Atomic level surface modification
• Material defects.

Typical Industries using AFM

• Corrosion
• Healthcare
• Medical devices
• Semiconductors
• Optics.