Abstract
Existing capabilities in chemistry and scanning probe microscopy make it feasible to undertake the development of instruments providing positional control of sequences of chemical reactions. Once developed, such instruments will enable the construction of nanoscale systems with precise molecular control. Improvements to previously proposed positional synthesis mechanisms are suggested, as are means for attaching protein molecules to surfaces with substantial rigidity. The latter capability would facilitate the development of positional synthesis systems by providing a means for binding and positioning reagent molecules in an atomic force microscope mechanism.