US Patent 7786402 - Nanospot welding

http://ip.com/patent/US7786402

This patent from Applied Nanotech teaches a way to construct perhaps the world's smallest welding tool by using a carbon coated AFM tip as an electron emission device. Claim 1 reads:

1. A method for creating a nanospot weld on a work piece comprising:

positioning a tip of a modified atomic force microscope (AFM) at a controlled distance from the work piece, wherein a cantilever beam of the AFM has the tip configured as an electron beam source;

activating the electron beam source to provide electrons directed towards the work piece by applying a controlled voltage potential to the electron beam source; and

modulating the voltage potential of the electron beam source or the controlled distance of the tip from the work piece to cause controlled local heating of the work piece thereby creating the nanospot weld on the work piece.