Above: Mechanosynthetic C2 donation. (A) Schematic of the inverted-mode STM setup. EAOGe-C2I molecules are deposited on flat Si(100), and an H-passivated Si(100) silicon probe chip (SPC) with a flat, crystalline apex is positioned above the surface. The molecules function both as imaging probes, where an applied bias (VS) drives a tunneling current (IT) through the molecule, and as reagents capable of chemically reacting with the build site. (B-E) Mechanosynthetic sequence showing the evolution of the build site as it is imaged with and modified by a molecule (Tool 1). As the build sequence proceeds, both the tool termination (inset) and atomic composition in the target area (white rectangle) change. Starting from a bare build site (B), two Si dangling bonds (DBs) are patterned by bias pulsing in an inter-row (IR) configuration (C), followed by molecule de-iodination (D), and transfer of a C2 unit to the DB pattern (E). (F) Small-area scan of the build site following the C2 transfer, centered on the target area and imaged with a new, intact tool (Tool 2). (G, H) Simulated STM image and geometry of C2 in the IR configuration (IR-C2), reproducing the experimental image shown in (F). Figure 1 from arXiv.
I've been working on the theory side for over 22 years for such an announcement, and it is beyond gratifying to be able to finally report on experimental advances.
https://arxiv.org/abs/2605.27250
From 1986, when it was first proposed by K. Eric Drexler, to 2026, when its first instances as envisioned by many in the community (to a basic extent, anyway) have now been experimentally demonstrated – subtractive mechanosynthesis of surface hydrogen atoms and now additive mechanosynthesis of carbon dimers on passivated Si(100).
Atomically precise, positionally-controlled mechanosynthesis. High reliability. Including the demonstration of C-C bond formation in the form of short polyyne chains in surface configurations never before reported in the literature.
"Hypothetical" on the wikipedia page until this morning (fixed it). The controversy over its feasibility was never to be settled until it was done in a lab. I am pleased to report, thanks to the efforts of a great team at CBN Nano Technologies, Inc., that the "hypothoversy" has found its end.
At the very least, any nay-sayers outside of the original molecular manufacturing, (amm) atomically precise fabrication (apf), or atomically precise manufacturing (apm) communities can now say with conviction "that's not what I meant!"
Had this been in place prior to what the United States National Nanotechnology Initiative became, the field and the world might be significantly different today. And now awaiting publication of my chapter this summer in a new three-volume set from Springer Nature on Radical Longevity, where I'm fortunate to have been invited to provide my own highly biased perspectives on where this and upcoming work might go in the next decade or two.
Authors: Cowie M., Deimert C., Groome R., Inayeh A., Mackie C.J., Myall J., Rohe S., Sandoval L., Sayed-Akhmad K., Thanabalasingam B., Wotton R., Addou R., Asani A., Blue B., Bottomley A., Clarcia K.A., Enright T., Fan J.Z., Freitas Jr. R.A., Godfrey A.T.K., Hill A., Huff T., Jobes M., Kirby R.J., Ma H., Maahs A.C., MacLean O., Maley S.M., Marshall M., McCallum T., Merkle R.C., Morin M., Plumadore R., Rodriguez H., Savoie M., Scheffel B., Wong J.L., Allis D.G, Barton J., Drew M., Kennedy M.R., Taucer M., Takatani T., Vobornik D., Yamachika R., Durand M.
CBN Nano Technologies, Inc. (CBNNT); Ottawa, K1Y 4W5, Canada
May 26, 2026
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.
