050123: A Reliable Process for Fabricating Single Nanowires and Nanotubes

In a broad class of future nano-devices, a key challenge will be to construct connections between electrodes using single carbon nanotubes (CNTs) or semiconductor nanowires (NWs). Current methods have major difficulties with repeatability and the ability to eliminate uncertainties. A major problem is that growing NWs or CNTs across an electrode gap is fundamentally a random process.


The method of this invention combines an electrophoresis deposition method with an atomic force microscope (AFM) based nano-manipulation system in a reliable and controllable way to deposit and precisely control the placement of individual NWs or CNTs to specified locations. After placing a drop of a NW or CNT suspension between two electrodes, an applied voltage traps the NWs or CNTs. The AFM probe then removes unwanted NWs and CNTs and re-positions a chosen NW or CNT to precisely bridge the gap between the electrodes.


  • Manufacturing enabler: Precisely positioned CNTs and NWs will be important building blocks in future molecular electronics devices.
  • Controllability and reliability of production process: The invention provides a potentially efficient and controlled process for fabrication of an electrode gap bridged by a semiconductor or conducting nanowire, eliminating the uncertainties with existing processes.
  • Usefulness in research: The invention provides an easy and reliable way to study nano-electronics and NW/CNT materials properties.


Manufacturing of components in future molecular electronics devices. The invention also has promise as a research tool for studying NW and CNT properties, and development of NW and CNT-based nanosystems.

IP Protection Status

US 7381625 (issued Jun 3, 2008)
Patent Information:


For Information, Contact:

Raymond Devito
Technology Manager
Michigan State University - Test