PEELING back ordinary sticky tape can generate bursts of X-rays intense enough to produce an image of the bones in your fingers.
That鈥檚 what Seth Putterman and colleagues at the University of California, Los Angeles, found when they used a motor to unwind a roll of sticky tape and recorded the electromagnetic emissions. Ripping the tape from its roll at 3 centimetres per second generated X-ray bursts lasting one-billionth of a second, each containing over a million photons (Nature, ).
The researchers suspect the emissions arise when the two surfaces involved acquire electrical charges of opposite sign. In this case, the adhesive becomes positive and the polyethylene roll negative. The charge difference builds until electrons jump from the roll to the adhesive, apparently with enough energy to produce X-rays when they hit the tape. 鈥淢y attitude is to marvel at the phenomenon. All we are doing is peeling tape, and nature sets up a process that gives you nanosecond X-ray bursts,鈥� says Putterman.
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The team is unsure why sticky tape produces such intense X-ray emissions, and plans to investigate whether factors such as the type of adhesive make a difference. The work may one day lead to new X-ray photographic devices.
