Researchers in Switzerland have developed a new technique for joining nanotubes. One technique, called "nanorobotic" spot welding, uses molten copper to join up objects in the same way that a human electrician might use solder. They position 50-nanometre-wide carbon nanotube filled with copper inside a nanorobotic manipulator, and run a small voltage through it to melt the copper. The copper can be used to make electrical connections with low resistance. They could run a voltage through a structure of nanotubes put together by self assembly or using electric fields. However, only a very small number of labs in the world have access to nanorobotic manipulators.
Gordeev, along with colleagues in the UK have developed another nanowelding method that only requires an electron microscope and turns carbon contaminants into amorphous carbon. The electron beam transforms tiny amounts of carbon-based contaminants into amorphous carbon. The amorphous carbon is similar to diamond. They create any 3D shape by varying the beam and rotating the target. Using this technique, the researchers have already made nano-scalpels 10 nm by 20 nm across and just a few nanometres thick. These scalpels can be used for cutting into living cells.