Alexander Berdyugin, a young scientist at the TSU Faculty of Radiophysics, is studying inhomogeneities in composite materials using terahertz radiation and a terahertz imaging system. The study will further improve the quality of composites used in medicine, rocketry, automobile production, and other industries.

When obtaining functional composite materials based on carbon nanotubes, graphene, bulbous structure carbon, and nanofibers, it is necessary to know the relationship between the required surface distribution of electromagnetic parameters and the main physical characteristics of the composite: the type and structural features of the active phase particles, their concentration, and the heterogeneity of the material itself. TSU radiophysicists proposed to solve this problem using terahertz visualization in a spectrometer.

- We are studying the heterogeneity of composites. We put samples of composite materials into a terahertz scanner. Then, the intensity of the radiation at each point is recorded, bringing the image together, like a photograph in the optical range. The short wavelength (less than 300 microns) helps us to look inside the object with a sufficiently high resolution. This is how we determine the homogeneity of materials, find defects, cracks; using our method, you can study the chemical composition. Also, our system can, for example, see pencil or charcoal sketches of paintings under a layer of paint, - said Alexander Berdyugin.

The software provides real-time data on the size and localization of the heterogeneity in the investigated composite sample. From them, scientists calculate the electrophysical parameters, which are needed to fill the databases of manufacturers of composite materials.

- The most important task is to improve the production methodology and quality control of composites. We send the images obtained in the terahertz spectrum to the manufacturers. From the data, the manufacturer can judge the degree of homogeneity of composite materials, the presence and spatial location of defects. This helps us to adjust the production technology and improve the quality and reliability of the materials produced, - explained Alexander Berdyugin.

Currently, scientists are at the stage of improving the technology of terahertz imaging of materials, increasing the spatial resolution, and expanding the functionality of the software.