We have been watching the emergence of Terahertz technology with a keen eye over the last few years. To engineers and physicists, the appeal of T-rays is understandable as the field of Terahertz imaging abounds with terms like “Gyrotron” and “Quantum Cascade Lasers.” The technology holds a lot of promise for future radiology devices and is already quite widely used for whole body scanning for airport security applications.
Attractive as the nomenclature may be, T-ray detection and imaging techniques have been limited by the inability to easily generate and detect the T-rays using conventional means. It seems the field has been gathering pace in the last number of years, largely driven by advances in technology to generate, manipulate and detect T-rays. These developments have also been accompanied by an increasing number of safety studies. One of the concerns about T-rays that has emerged from theoretical studies is the possibility of pulsed T-ways amplifying and destabilizing hydrogen bonds between DNA strands, causing them to break. This was the focus of a collaborative study between physicists at the University of Alberta and molecular biologists at the University of Lethbridge in Canada published earlier this week.
A special gel-based analysis used to detect specific proteins shows elevated levels of gamma H2AX, the marker for DNA damage. It shows that there are elevated levels of the protein in the THz-pulse exposed tissues compared to control samples that weren’t exposed. Credit: Biomedical Optics Express
The team undertook an experimental study on the effects of intense, pulsed T-ray exposure on lab-grown human skin tissue, at a level far higher than would typically be used in real world applications . They then examined the exposed samples and unexposed control samples 30 minutes after exposure for evidence of phosphorylated H2AX, which marks a DNA double strand break site. Significantly higher levels of phosphorylated H2AX were found in the exposed samples leading the team to conclude that the high intensity T-ray exposure was responsible.
While the safety limits of safe T-ray exposure continue to be explored, innovation progresses around producing higher resolution, lower-cost T-ray devices. In January of this year engineers from Ohio State University, Columbus published details of a light-weight, low-cost prototype T-ray camera using state of the art electronic detection circuitry.
Unlike traditional cameras, the T-ray camera replaces the CCD sensor with Terahertz-sensitive antennas which capture the T-rays before being processed into an image. The device is currently sensitive to an area of 31 x 31 pixels and the team managed to record and process images at a rate of 5Hz, producing low frame rate video.
The core camera circuitry can be produced with existing, mature electronic fabrication techniques and the team believes they can increase the resolution of their system from its 31 x 31 pixel limit. A detailed description of the camera and its performance has been published in the journal IEEE Transactions on Antennas and Propagation.
There is no doubt that this field will continue to progress at an exciting pace and we look forward to the emergence of new T-ray medgadgets in the future.