ABSTRACT
Single-walled carbon nanotubes (SWNTs)1,2 are single layer, graphitic molecular tubes with exceptional material properties3 that are well suited to diverse applications in nanotechnology. ¡ey are typically less than 2 nm in diameter, but can be centimeters long.4 ¡ey possess very high thermal conductivity, mechanical strength, sti«ness, and chemical stability.3 Individual nanotubes are metallic or semiconducting, depending on chirality5 (Figure 31.1). Semiconducting SWNTs have ¢nite band gap and intrinsic carrier mobilities on the order of 100,000 cm2 V−1 s−16. Both types of SWNTs are 1D quantum wires7,8_ ENREF_6 with unusual electronic9 and optoelectronic properties,5 including ballistic conductance.9-11
Over the past two decades, research has uncovered numerous potential applications for these unique materials. For example, future integrated circuits may achieve higher switching speeds and lower power dissipation using SWNT-based ¢eld e«ect transistors6,12-17 and interconnects.18 SWNTs can also function as nanoelectromechanical devices,19 including prototype nonvolatile memory elements20 and vibrational mass sensors.21,22 Since all the atoms in SWNTs are on the sidewall, the conductance and ¦uorescence of semiconducting SWNTs are very sensitive to the presence and conformation of surface-associated charged molecules and surface defects.23 ¡is has enabled electronic23-26 and optical27 detection of chemical27,28 and biological24,29-31 analytes. SWNTs have also been used as nanoscale
31.1 Single-Walled Carbon Nanotubes................................................ 1017 31.2 Recent Advances in SWNT Synthesis, Puri¢cation,
and Fabrication ............................................................................... 1018 31.3 Shortcomings in Technology for SWNT Device
Construction ...................................................................................1019 31.4 Structural DNA Nanotechnology ................................................1020 31.5 Generating Irregularly Shaped DNA Structures .......................1022 31.6 DNA-Directed Assembly of SWNT Devices ..............................1023 31.7 SWNT Organization on a DNA Origami Nanobreadboard ...1024 31.8 Linker-Induced Surface Assembly of Parallel SWNT Arrays ..... 1026 31.9 Unmet Challenges in DNA-Directed Assembly
of SWNT Nanoelectronics ............................................................1027 31.10 Future Opportunities .....................................................................1028 References ....................................................................................................1029
