It may sound bizarre—or like some kind of high school science fair project, but it's not: Researchers have discovered that peeling adhesive tape ejects enough radiation to take an x-ray image. If they stick, the findings could set the stage for a less expensive x-ray machine that does not require electricity.
Lead researcher Carlos Camara, a physicist at the University of California, Los Angeles, reports in Nature today that his team captured x-rays of a finger on film (positioned behind it) by using a simple tape-peeling device (placed in front of it).
How is that possible? It turns out that radiation is released when tape is ripped from a surface. The reason, says Camara: electrons (negatively charged atomic particles) leap from a surface (peeling off of glass or aluminum works, too) to the adhesive side of a freshly yanked strip of tape, traveling so fast that they give off radiation, or energy, when they slam into it.
The result of this process when recorded by radiographic film is a fuzzy x-ray of the finger bone of physicist Seth Putterman, who runs the lab in which it was made.
"We have high hopes that this can be a very inexpensive alternative source of x-rays good enough to take x-ray images," Camara tells ScientificAmerican.com.
Conventional x-ray machines require expensive electrical components to create a beam of high-energy electrons that is aimed at a metal target. Camara envisions an x-ray device in which the adhesive tape could be peeled by a hand crank—and rolled back up for use again. He notes that researchers reused the same roll of tape many times without any change in x-ray quality. Unfortunately, he says, whether via the traditional method or the tacky one, it still requires the same amount of radiation to create an image.
Worried about radiation from the tape dispenser on your desk? Don't. In both a conventional and the experimental x-ray machine, electrons travel unhindered by air molecules through a vacuum chamber; that allows them to produce the higher energy needed to make x-rays. Normal air, comprised of nitrogen and oxygen and other gases, slows the electrons to a pace that is so sluggish there is only enough energy left to produce a faintly visible, benign blue light.
Don't believe us? Check out the property called triboluminescence yourself by peeling tape in the dark.