Nanorobotic Spot Welding by Attogram Precision Metal Deposition from Copper-filled Carbon Nanotubes

Nanorobotic spot welding using single-crystalline-copper-filled carbon nanotubes (CNTs) is investigated experimentally inside a transmission electron microscope (TEM). Controlled melting and flowing of copper inside nanotube shells are realized by applying bias voltages between 1.5 V and 2.5 V. The average mass flow rate of the copper was found to be 120 ag/s according to TEM video imaging (measured visually at approximately 11.6 nm/s through the CNT). Successful soldering of a copper-filled CNT onto another CNT using a nanorobotic manipulator shows promise for nano spot welding, which can play a role similar to its macro counterpart for the interconnection of nano building blocks for the assembly of nanoelectronic circuits and nanoelectromechanical systems (NEMS).