 A layer of 29% iron enriched single-walled nanotubes (SWNT) placed on top of a layer of explosive material such as PETN can be ignited with a regular camera flash.CNTs can be used as electron guns in miniature cathode ray tubes (CRT) in high-brightness, low-energy, low-weight displays.A display would consist of a group of tiny CRTs, each providing the electrons to illuminate the phosphor of one pixel, instead of having one CRT whose electrons are aimed using electric and magnetic fields.