Researchers at the University of North Carolina say their work is another step toward developing scanners for medical imaging and homeland security that are smaller, faster and less expensive to operate.

"The current CT scanners take images sequentially, which is slow and inefficient. Using the nanotube X-ray technology, we show ... the feasibility of multiplexing -- taking multiple images at the same time," said Otto Zhou, UNC professor of materials science.

Carbon nanotubes, made of layers of carbon atoms, can be as small as one nanometer, or one billionth of a meter in diameter and emit electrons without high heat.

The research appears in the current edition of the journal Applied Physics Letters.