Fig. 1. Schematic diagram illustrating the programmed assembly of nanoparticles along attachment lines on a DNA scaffolding. Colored segments represent DNA strands that self-assemble into molecular tiles which form a two-dimensional structure. Particles and other nanocomponents precisely attach to the scaffolding along lines by Watson-Crick base pairing. The development of electronic circuitry based on nanoparticles, molecules, and other nanoscale devices will require a major paradigm shift involving circuit architecture, device principles, and fabrication technologies. Due to basic design constraints imposed by power dissipation limits and the interconnect bottleneck, nanoscale circuitry will be dominated by ultrasmall components laid out in regular patterns and connected locally [1,2]. The realization of such circuitry will require a radically new method for precision assembly of nanocomponents into regular arrays. In this project, we are investigating the use of DNA as a scaffolding for the programmed assembly of nanoelectronic component arrays. An example of the assembly of a nanocomponent array by DNA scaffolding is illustrated schematically in Fig. 1. Rather than using the lithographic techniques of conventional semiconductor chip manufacturing, this approach exploits programmed Watson-Crick base-pairing for self-assembly at the nanoscale. In this design, the base sequences for 22 different types of single-stranded DNA are programmed so that a mixture of strands self-assembles into tiles comprised of double-crossover (DX) molecules (represented by 5-color cells in Fig. 1), which in turn assemble into a two-dimensional crystal. Nanoparticles, or other nanoscale components, are assembled into the scaffolding by covalent attachment of the particles to one type of DNA strand, thereby offering a precision limited only by the 0.34-nm nucleotide separation of the DNA duplex. The goal of this project is to identify and address basic scientific and engineering challenges toward proof of concept for this approach. Our team from electrical and computer engineering, chemistry, and physics is carrying out a range of studies to systematically explore basic chemical, physical, and electronic issues related to nanoparticle/DNA design, chemical compatibility, assembly methods, electrostatic interactions, electronic transport, and interactions with surfaces. This research will help lay the groundwork for the development of a DNA nanotechnology for the precise assembly of components for electronics and other applications.