APPLICATIONS OF TECHNOLOGY:

• Commercial – potential scalable technique for industrialization of nanoscale carbon-based electronic devices
• Research -- will enable detailed studies of carbon nanotubes (transport, mechanical measures, and spectroscopy)
  

ADVANTAGES:

• Allows precise control of deposition of CNTs at predetermined locations
  
• Enables easily directed assembly of carbon nanotubes onto a substrate
  
• Vastly increase CNT device yield
  
• Increases production time

(a) Scanning Electron Microscope image of the silicon MEMS device for nanotube deposition. The inset shows the teeth pairs in the center of the device. (b) A straight nanotube stretches across a pair of contacts.

ABSTRACT:

Alex Zettl and Yan Mei Wang have taken another step toward enabling the commercialization of nanoscale carbon-based electronic devices through devising a deposition method that results in the successful self-assembly of carbon nanotubes. Although many carbon nanotube (CNT) based electronic devices have shown great potential for application, their integration into larger units such as integrated circuits has not been practical because of the precision required in the deposition of the CNTs at predetermined locations. Up to now, CNT devices have been made one unit at a time using an inefficient random search and bond method.

Zettl and Wang have developed a more efficient method, allowing the CNTs to self-assemble onto a Si MEMS (microelectromechanical systems) assembler device (~3 mm wide). Single CNTs are suspended in acetone and dropped onto a predetermined position on these pre-etched thin Silicon wafers. The acetone dries in 20 seconds, at which time almost all of the CNTs attach to the patterned contact area in the Si wafer, thus assembling in a pre-determined manner. The entire process takes less than one or two minutes, and the successful yield of single CNT devices is 20–50%. This technique could potentially serve as the basis for scalable production of CNT electronics devices.

STATUS:

• Published Patent Application. Available for licensing

REFERENCE NUMBER: IB-1768

SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:

• Metallic Carbon Materials, IB-1180
• Nanotube Heterojunctions, IB-1181
• C36--A New New Class of Buckyballs, IB-1366
• Nanotube Bearing and Spring, IB-1649