A paper in the latest issue of Nature has revealed that peeling sticky tape can produce X-rays.
It has been known since 1939 that tape can produce visible light when peeled. This is called triboluminescence, and is due to the energy released during the breaking of the chemical bonds between the two layers of tape.
The research by a group of scientists at the Department of Physics and Astronomy of University of California in Los Angeles found that in addition to this visible light, tape could also produce X-rays and radio waves, both forms of electromagnetic radiation but with different wavelengths to that of light.
They used an interesting looking set-up (left) to search for the X-rays. An automated peeling machine removed the tape with a measurable force, whilst a detector looked out for an X-rays that were emitted. All of the equipment had to be placed in a vacuum, as the X-rays cannot normally be generated otherwise – which means that you’re safe when reaching for the office supplies.
The X-rays are produced as electrons jump from the main roll to the sticky side of the peeling tape. When they hit the other side they slow down, losing energy in the process. This energy has to go somewhere, and it just so happens to come out as X-rays.
It’s not all fun and games however, as the X-ray tape could have useful applications. Medical X-rays are made using costly and bulky equipment, but with some refinements the team believe that inexpensive X-ray machines could be produced for use by paramedics, or places where access to electricity is limited – all you need is a bit of tape. The researchers have applied for a patent on the concept. They were able to produce an image of one of the team’s thumbs: