Directed assembly of single-walled carbon nanotubes and other nanoscale building blocks


Yuhuang Wang1, Daniel Maspoch2, Shengli Zou2, George C. Schatz, schatz@chem.northwestern.edu3, Chad A. Mirkin, chadnano@northwestern.edu3, Roie Yerushalmi, guihuayu@cmliris.harvard.edu4, and Charles M. Lieber4. (1) Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, (2) Institute of Nanotechnology and Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60201, (3) Department of Chemistry and the International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208-3113, (4) Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA 02318
Directed assembly of nanoscale building blocks such as Single-Walled Carbon Nanotubes (SWNTs) into desired architectures is a major hurdle for a broad range of basic research and technological applications (e.g. electronic devices and sensors). Here we report a parallel assembly process that allows one to simultaneously position, shape, and link SWNTs with sub-100 nm resolution. Our method is based upon the observation that SWNTs are strongly attracted to COOH-terminated self-assembled monolayers (COOH-SAMs) and that SWNTs with lengths greater than the dimensions of a COOH-SAM feature will align along the boundary between the COOH-SAM feature and a passivating CH3-terminated SAM. Because SWNTs are assembled along the boundary between hydrophilic and hydrophobic SAM features, the resolution of assembly is significantly improved. By using patterned chemical templates, we have formed SWNT dot, ring, arc, letter, and even more sophisticated structured thin films and continuous ropes. Theoretical modeling and the generalization of this assembly technique to other nanoscale building blocks including semiconducting nanowires and magnetic nanoparticles also will be reported. (Dedicated to the memory of Prof. Rick Smalley)