Some thoughts about scanning probe microscopy, micromechanics, and storage

Interaction and actuation mechanisms used in scanning probe microscopies (SPM) have inherent potential for storage applications, but many unresolved conceptual and technical questions have precluded a thorough assessment of this potential so far. However, the intrinsic properties of SPM instrumentation and tip/sample interactions allow a number of important parameters and their ultimate values to be estimated. Coping with and possibly surpassing established technologies will require massive parallelism of SPM-type recording heads, a condition that might be satisfied in an elegant manner by using SPM-type, circulating piezoelectric flexural actuators. Operation of an entire array of recording heads will require highly precise micromechanical manufacturing and/or sophisticated control mechanisms. The resulting tolerance requirement can be relaxed by choosing long-range SPM interactions (Coulomb forces, capacitance, near-field optics, etc.). Furthermore, the interaction must allow a high recording speed. The restriction to read-only storage can facilitate exploratory work; the writing process in this case might be replaced by replication, similar to the techniques used in the production of compact disks.