If you want a detector to pick up more light, the technique has usually been to increase the intensity of the X-rays. But this obviously has associated health risks.
Yi and his team believed that if they could improve the scintillation material so that it reemitted more light from the same amount of X-rays, then they could create safer medical imaging devices. To do this, the researchers needed to create a new class of materials.
What they came up with is based on a thin film made from cerium-doped lutetium oxyorthosilicate crystals. They were then able to cover these crystals with pyramid-shaped bumps made of silicon nitride. It is these bumps that make the scintillator appear like the moth’s eye and give the structures its ability to extract more light.
The results have been pretty dramatic. Yi and his team measure that adding their moth-eye-inspired thin film to the scintillator of an X-ray mammographic unit increases the amount of reemitted light by 175 percent.
“The moth eye has been considered one of the most exciting bio structures because of its unique nano-optical properties,” Yi says in Nanomagazine article. “Our work further improved upon this fascinating structure and demonstrated its use in medical imaging materials, where it promises to achieve lower patient radiation doses, higher-resolution imaging of human organs, and even smaller-scale medical imaging. And because the film is on the scintillator,” he adds, “the patient would not be aware of it at all.”