STEP-BY-STEP SURFACE ASSEMBLY

Abstract

MOLECULAR MANUFACTURING'S ultimate goal of assembling molecular machines atom by atom may be a long way off, but a research team in Europe has come a step closer to assembling structures molecule by molecule. In an elegant meeting of chemistry and mechanics at the single-molecule level, Anne-Sophie Duwez, a materials scientist at Belgium's University of Liege, and colleagues use an atomic force microscope (AFM) to covalently attach individual molecules to a surface, making and breaking each bond individually ( Nat. Nanotechnol ., DOI: 10.1038/nnano.2006.92). The ultimate physical limit in the design and fabrication of organic surfaces can be reached using this approach, according to Duwez. To achieve their mechanosynthesis, Duwez' group grafts poly- N -succinimidyl acrylate onto a gold-coated AFM tip. They then carefully bring this modified AFM tip into contact with a silicon surface functionalized with primary amines. A nucleophilic amine attacks a reactive carbonyl on the polymer, forming an amide lin...