Hi,
I was thinking about focused ion beam for deposition/etching/cutting material, I think if there is more than one type of element available, ideally switchable in real time, this could allow for some neat technologies, such as depositing layers of material for different properties (semiconductors etc).. So I don't know if there are systems out there already that can do this with multiple elements, but one idea I had was to use an alloy or homogeneous source for the ions, instead of a pure metal for the ion source, and atomize small amounts off the surface of this with a laser to create ions. Then add a "mass spectrometer" section into the ion accelerator path of the FIB (focused ion beam) setup, and use the mass spectrometer to select which of the elements from the ion source to deposit by changing the deflection coil current in the mass spectrometer.
Another way to make a multi-element focused ion beam could be to have small 1mmx1mmx0.1mm thick plates in a 2D chess board array, each of a different element, and target a laser at the desired element to vaporize a small amount to go into the ion beam. That method could allow easier simultaneous deposition of elements with different masses if there is more than one laser too.
cheers, Jamie