Sensor or "Nano-hammer?"
The Atomic Force Microscope (AFM) is used to make pictures from a surface, but its tip can also be used to modify this surface and produce nano-structures.
A standard cantilever AFM with a tip sitting on a flexible arm can only apply small forces. Using a Nanomotor driven AFM increases the applicable forces 1000 times, and even allows to produce tip imprints into diamond surfaces.

The principle
The detection of the sample surface with a shear-force sensor decouples the sensitive sensor from the movements of a tool towards the sample, see Fig. 1. The shear force sensor oscillates parallel to the surface and the amplitude of the oscillation is measured. Within a short distance between sensor and sample shear-forces occur, which cause a damping of the oscillation.

Nanomachine Factory II with AFM-STM head fixed at a small granite bridge over a Nanorobotics base stage for sample mapping

Applications
A diamond tip was used as engraving and measuring tool. The AFM-pictures were taken with the same tip immediately after modifying the surface.
Fig. 3 shows a tip imprint in a diamond surface, that was produced by "hammering" the tip into the surface in coarse step mode with accelerations of 50 G.

The imprints of Fig. 4 were made in nickel with increasing depth, measured afterwards in the same device at the same position: in scanning mode and as line-scan (Fig. 5). Even reproducible tip imprints in sapphire can be made with the same precision as in soft nickel.

Since the AFM can measure the depth of the produced structures exactly, an algorithm to engrave "invisible" small 3D-structures in surfaces in closed loop control is possible. Bitmaps could be transferred onto the surface three-dimensionally, transforming the color information into a depth profile.

Leaflets describing this instrument are available in the "Downloads" area on the right.