A finger x-ray made with Scotch tape; in the background, a vacuum chamber
with a roll of Scotch tape mounted on ball bearings inside
Scientists have found that the everyday Scotch tape you use to tape paper and other household materials has another use: it produces X-rays.
The researchers, from the University of California at Los Angeles, said they were very surprised at the discovery. They were investigating a report that Soviet scientists found that peeling sticky tape releases pulses of X-rays.
After unwinding a standard roll of Scotch tape in a vacuum, using a motorized peeling machine at a rate of three centimeters per second, the UCLA scientists also observed X-rays. They measured that the X-rays were powerful enough to take images of bones in fingers and hands. With these results, the researchers predict that X-rays emitted by tape could have some useful applications, since it’s quick, cheap, and potentially safer than conventional X-ray machines.
Researcher Carlos Camara said that they did not know exactly how the tape produces x-rays, but explained that the key is when two contacting surfaces move against each other. As the tape peels, the sticky part likely becomes positively charged, while the non-sticky polyethylene becomes negatively charged.
Electric fields can build up and cause electrons to fly from one side to the other at high speeds when under reduced atmospheric pressure, such as in a vacuum. The electron movement results in X-ray pulses of 100 milliwatts that last for a billionth of a second.
The researchers noted that the effect only occurs in a vacuum, so peeling tape in your home or office won’t subject you to harmful radiation.