Atomically precise mechanosynthesis of carbon structures on hydrogenated Silicon

Researchers have demonstrated atomically precise mechanosynthesis of carbon structures on silicon surfaces using inverted-mode scanning tunneling microscopy (STM). By donating C₂ units from surface molecules to reactive sites on hydrogen-passivated Si(100), they achieved controlled single and multi-site carbon placement and assembled polyyne structures through successive C-C bond formation. This work establishes a foundational capability for programmable, atom-by-atom nanofabrication with complete control over atomic placement and chemical bonding.