Pacific Nanotechnology Inc.

Surface Modification

Mechanical Surface Modification

The Atomic Force Microscope was initially developed to image the surfaces of insulating materials. However, by accident, it was discovered that the AFM probe could cause mechanical modifications to a surface. Such mechanical modifications can now be used proactively to alter surface topography.

Two types of mechanical surface modifications are possible. In the first, the probe is pushed into the surface. In the second, a line is scratched into the surface. The size of the features depends on the following factors:

Surface Material (hardness)
Probe Diameter
Probe Material (hardness)
Force of the Probe on the Surface
Probe Temperature

Figure 1 illustrates and example of an AFM used to indent ~0.4 µm diameter depressions in a material's surface.

Figure 1: Mechanically modifying a surface. After indenting a 3X3 array of depressions ~ 0.4 µm in diameter and ~ 50 nm deep; image depth range: 103 nm. The image has an area 5.2 µm square.