Last weekend I came across a piece of science news that blew my mind, really it was so unexpected I had to share it (late, oh well). Apparently researchers at the University of California have shown that simply peeling sticky tape (in this case 3M Scotch Tape) can release X-rays. Before you consider donning your lead apron to perform your office duties it must be said that these experiments were carried out in a vacuum and that exposure to air quenches this effect. Even so this is still an amazing discovery, the X-rays were powerful enough to allow the researchers to take an X-ray image of a finger bone. That means this process could allow for cheap and easy X-ray machines for third world countries or emergency aid kits that do not require power to run, all you need is to unwind the tape.
Interestingly they tested a variety of different types of tape and while Duct tape did not produce the rays when peeled from itself it did when peeled from aluminium so there is the potential to use different combinations of materials to customize the ray output of the system. The researchers also theorize that the x-rays produced could be used to kick start fusion if the tape was doped with deuterium and tritium although an engineer at UKAEA Culham Division considers the overall system unworkable as the amount of power produced would probably not even be enough to run the mechanism unwinding the tape.
The exact mode of action that is creating the x-rays is not yet fully understood (3M keeps their glue formula a trade secret) but the basic idea is that when the tape is peeled back the roll becomes negatively charged while the adhesive becomes positively charged. This sets up conditions whereby electrons will jump from the roll to the adhesive and in doing so generate the X-rays when they hit. This is the same way visible light is produced in the same situation and is called triboluminescence. Isn’t that amazing? The world around us is full of mysteries and when it comes to revealing them, science delivers.
http://www.ohgizmo.com/2008/10/23/science-thursday-x-ray-yourself-with-scotch-tape/ – This one has a video!