Recent advances have been made in nanowire fabrication that could allow tiny devices to be constructed that could revolutionize diagnostic medicine. Devices have been created that emit terahertz radiation, which can pass through tissues such as skin, but in contrast to other forms of radiation used in medical imaging such as X-rays, they are not harmful to living tissues.
The nanowires from which the devices are constructed are around 100 times thinner than a human hair. The researchers have developed a technique for turning these nanowires into devices that could potentially be used in medical imaging. The resultant images that could be generated would have a higher resolution than ultrasound and could therefore be used to detect small cancers, which are difficult to identify using conventional imaging techniques. The detection of smaller tumors would mean treatments could be started far more quickly, giving patients a better chance of making a full recovery.
University of Strathclyde researchers have been working on nanofabrication techniques for several years. Assisted by researchers at the University of Oxford and the Australian National University (ANU), a technique was developed to assemble the nanowires into a 3D lattice using a transfer printing process to create semiconductor structures in orthological patterns, which are printed onto metal antenna structures. The technique allows precision control of manufacture with nanoscale accuracy. ANU has experience of growing the semiconductor nanowires, while the researchers at the University of Oxford developed advanced light detection technology which helped create the tiny devices.
“Building the THz detection systems was a great challenge that required the development at Strathclyde of extremely precise nanofabrication processes. These permitted us to use the semiconductor nanowires from ANU as ‘building blocks’ for their sequential integration in the 3-D THz detectors designed at Oxford, whilst keeping the nanometric accuracy needed to assemble the systems,” Dr. Antonio Hurtado, Senior Lecturer in Strathclyde’s Institute of Photonics and one of the lead researchers on the team. “This has been a great combination of capability and a fantastic collaboration between the different teams involved in this work.”
Terahertz radiation systems have already been developed for use in security scanners at airports, but the technology is not yet at a stage where it can be used in medical imaging. The latest research has made significant improvements to the technology, which could well pave the way for a new class of medical imaging system that could provide accurate imaging without the risks associated with other forms of radiation.
You can read more about the study in the paper – Three-dimensional cross-nanowire networks recover full terahertz state – which was recently published in the journal Science. DOI: 10.1126/science.abb0924