Toward Mechanosynthesis of Diamondoid Structures: IX Commercial Capped CNT Scanning Probe Microscopy Tip as Nowadays Available Tool for Silylene Molecule and Silicon Atom Transfer

According to Drexler, advanced mechanosynthesis will employ advanced nanomachines, but advanced nanomachines will themselves be a product of advanced mechanosynthesis. This circular relationship must be resolved via SPM technology development. In this article the possibility of using easily available commercial CNT tips to assembly silicon-based intermediate generations of nanodevices is considered. Mechanosynthesis of a target class of silicon-based nano-devices will require molecular tools capable of transferring SiH₂ molecules and Si atoms to reaction centers that have binding energies within –2.9 ± 0.2 eV and –6.8 ± 0.3 eV, respectively. Desirable properties for tools include near exoergic transfer of moieties to these structures; good geometrical exposure of moieties; and structural, electronic, and positional stability. The results presented in this paper suggest that CNT tips presently available on the market have properties enabling them to become tools for silylene molecule and silicon atom transfer into a reaction center during positional mechanosynthesis. The surpassing features of the commercial single/double wall capped CNT tips, such as small tip radii, extreme aspect ratio, excellent wear-out behavior and the average binding energy of ∼ –3.2 eV (for SiH₂ and ∼ –6.0 eV (for Si), make them ideal tools for bridging present day SPM technology and the future implementation of intermediate silicon-based nanotechnology.