Atomic precision engineering of advanced materials
John N. Randall, Zyvex Labs, Richardson Texas, USA
The ultimate goal of nanotechnology is to allow the creation of materials, devices, and applications that can be created by engineering at the atomic and/or molecular scale. In this presentation, two distinct approaches are used to create advanced materials. In the first example, the engineering of the chemical and mechanical interface of carbon nanotubes and their polymer host to make superior polymer composites for structural applications. This technology also provides straightforward processing of manufactured raw nanotubes which produces excellent dispersions of the carbon nanotubes without damaging the nanotubes. This is all done with conventional chemistry and without changing the manufacturing process of the composites. The second example takes advantage of chemistry but enables top down control of the placement of individual atoms and accomplishes this by a radical change in manufacturing processes. An ultra-high vacuum (UHV) scanning tunneling microscope (STM) is used to pattern a monolayer of H atoms that are on a Si (100) surface with atomic precision. This can be conceived of as spatially controlled deprotection, where the resulting unsatisfied covalent bond can react with a specific species delivered to the surface from the gas phase. The patterning process, which is a variation of e-beam lithography and subsequent additive processing can be considered digital fabrication. This digital fabrication process can be used to create unique materials as well as three dimensional structures. This paper will describe some of the chemistry and physics of both examples, provide some results, and discuss applications.