There are many AFM applications where the scan size exceeds 10 µm while characteristic size of the surface features is larger than 30 nm. For these applications, the lateral resolution is of less importance compared to other characteristics of AFM probes such as mechanical durability and ability of contamination . Furthermore, many AFM applications require blunt tips to allow quantitative measurements of various physical properties of the sample (friction, indentation, adhesion).

Contact mode

Long Scanning probes offer larger tip-sample contact area resulting in higher loads exerted to sample. However, these probes can still be used in Contact mode on hard samples.

Contact electric techniques may require cantilevers with higher spring constants than in regular Contact mode (up to 50 N/m). Relatively soft (0.03..0.3 N/m) conducting cantilevers are optimal for higher lateral resolution. Cantilevers with higher spring constant are better for quantitative measurements. Pt coating offers the highest resistance to wear and electromigration firmness as well as minimum tip radius of 20..25 nm.

Tapping mode

The choice of LS probe tips with a radius of 30-nm radius is reasonable for routine surface investigations of large surface areas (>10 µm) with surface features larger than 30-nm in size. Here, LS probe provides resolution comparable to GP and HI'RES-C probes. LS probes also allow long-term experiments due to the enhanced mechanical durability.

For imaging in liquids, one can choose probes with chemically stable overall Cr-Au coating. The tip radius with the coating is about 50 nm.

To image electric properties of materials using two-pass techniques, one needs probes with conducting coatings. The coatings may increase the probe tip radius up to 25..50 nm. Pt coating giving a tip radius of 25 nm is the best choice in terms of both resolution and durability.

The probe tip radius with Co-Cr magnetic coating is 90 nm. As the size of magnetic domains is usually more than 50 nm, this is usually enough for MFM.