The resolution in AFM depends on the shape of surface features, mechanical properties of the sample, and its interaction with the tip. There are many of AFM applications where the size of the surface features to resolve is in the 10..150-nm range; thus not requiring tips with a radius smaller than 10 nm. Figures below demonstrate clear resolution of large macromolecules along with submolecular features such as branches.

High resolution may not be attainable when imaging real-time processes such as molecular diffusion, crystallization, and wetting. This depends on the characteristic process rates in relation to the scanning rate and the distance between the scan sampling points. Moreover, sharp probes needed for high resolution imaging require special care in use, which leads to further reduction of the scanning speed. 10-nm resolution offered by General Purpose tips may be a compromise in this case.

General Purpose probes are uncoated silicon tips that can be usually used in Contact, Non-contact or Tapping mode for imaging topography and mapping mechanical properties without significant limitations. Imaging of DNA is one of the examples of such applications (see Fig.2).
 

General Purpose probes having tips with a radius of about 10-nm provide good-quality images for a broad variety of samples. The best resolution is achieved when scanning spherical particles that are hard and exhibit weak attraction to the tip. Note that the resolution of AFM images larger than 1µm by 1µm may be more determined by the density of sampling points ratio than the General Purpose tip radius.

General recommendations apply to the cantilever choice. Contact mode needs probes with small spring constant below 1N/m, Non-contact mode requires high-frequency probes, while cantilevers with intermediate spring constant and resonant frequency are optimal for most of samples in Tapping mode.

Diamond tips (SCD) have some benefits in these applications compared to silicon (NSC/CSC series). The properties of Diamond make the probes more durable, chemically stable and less contaminating. Diamond tips are also sharper than silicon (tip radius about 7 nm) and have smaller cone angle (about 20°).