The specification describes a method for selectively depositing carbon nanotubes on the end face of an optical fiber. The pumping system is composed of a two- or three-chambered canister within which solids, liquids, and gases can be separated from one another. A minimally inductive electrical contact mechanism electrically couples the electronics to the probing tip when the probing tip cartridge is in mating relationship with the main probing head body. 02, and the total stretch ratio is at most 6.