An international team of researchers has identified key design parameters for making curved X-ray detectors that could lead to better quality, safer X-rays.
In recent years, digital flat panel detectors have enabled radiographers to examine X-rays more quickly compared with old-fashioned photographic films, resulting in quicker diagnoses. However, flat panels are not suited to the complex shape and geometry of the human body.
The research team, led by Surrey University, said that reliance on flat panels means there is unavoidable distortion around the edges of images. Flat panels also prevent an accurate registration of the X-ray dose delivered, a key feature toward enabling safer radiation therapy and minimising secondary tumours.
Efforts to create flexible detectors have so far been unsuccessful due to the brittle characteristics of the rigid inorganic semiconductors used to make them. Some curvature has been achieved through using a thinner layer of semiconductor, but this has compromised performance levels and resulted in poor quality images.
Published in Advanced Science, the new study identifies design rules for a special class of ‘inorganic in organic’ semiconductors. The work is a collaboration with Italy’s University of Bologna, the National Physical Laboratory and Sheffield University. It explains that by tuning the molecular weight of the bismuth oxide nanoparticle sensitised organic semiconductors to lengthen the polymer chains, researchers could pave the way for more robust, curved digital detectors with high sensitivity or digital film.
“Our curved detector concept has shown exceptional mechanical robustness and enables bending radii as small as 1.3mm,” said Prabodhi Nanayakkara, lead author of the study and PhD student at Surrey University.
“The use of organic or ‘inorganic in organic’ semiconductors is also far more cost effective than conventional inorganic semiconductors made from silicon or germanium, which require expensive crystal growth methods. Our approach potentially offers a significant commercial advantage.”
Professor Ravi Silva, director of Surrey’s Advanced Technology Institute, said that the technology will help create a ‘revolutionary’ high sensitivity X-ray detector that is scalable due to the design and materials adopted.
“This technology has huge potential in medical applications and other X-ray uses, so we’re working with a spinout company, SilverRay, and hope to turn this technology into the X-ray detector of choice for high sensitivity, high resolution, flexible large area detectors.”
