The ability to build atomically precise structures on surfaces with complete control over both atomic placement and chemical bonding remains a central challenge in nanoscale fabrication. Here, we demonstrate simultaneous spatial and chemical control over the mechanosynthetic fabrication of carbon structures. Using inverted-mode STM, C2 units are donated from surface-deposited molecules to pre-patterned reactive sites on a hydrogen-passivated Si(100) surface. We demonstrate single-site C2 donation, spatially patterned multi-site C2 donation, and the stepwise assembly of polyyne structures through successive C-C bond formation. Together, these results establish controlled mechanosynthetic donation as a foundational capability for programmable atomically precise fabrication.
@article{arxiv.2605.27250,
title = {Atomically precise mechanosynthesis of carbon structures on hydrogenated Si(100) by inverted-mode STM},
author = {Megan Cowie and Chris Deimert and Ryan Groome and Alex Inayeh and Robert J. Kirby and Cameron J. Mackie and Jonathan Myall and Sam Rohe and Luis Sandoval and Khalil Sayed-Akhmad and Bheeshmon Thanabalasingam and Reid Wotton and Rafik Addou and Aly Asani and Brandon Blue and Adam Bottomley and Kareem A. Clarcia and Tyler Enright and James Zhangming Fan and Robert A. Freitas and Alan T. K. Godfrey and Si Yue Guo and Aru Hill and Taleana Huff and Mark Jobes and Hadiya Ma and Adam C. Maahs and Oliver MacLean and Steven M. Maley and Michael Marshall and Terry McCallum and Ralph C. Merkle and Mathieu Morin and Ryan Plumadore and Henry Rodriguez and Marc Savoie and Benjamin Scheffel and Janice L. Wong and Damian G. Allis and Jeremy Barton and Michael Drew and Matthew R. Kennedy and Tait Takatani and Marco Taucer and Dusan Vobornik and Ryan Yamachika and Mathieu Durand},
journal= {arXiv preprint arXiv:2605.27250},
year = {2026}
}
Comments
Supplementary Information is available upon request