47 stories in total
Elena Kopoleva, Elena Petrova, Maria Timofeeva and Pavel Filatov won grants in a competition for undergraduate and postgraduate students at St. Petersburg universities.
Iriney Vasilev will study optical methods for measuring temperature at the nanoscale using upconversion nanoparticles in biological media.
Lidia Mikhailova gave an invited lecture at the 10th International School for Young Scientists «Nonlinear and Biomedical Photonics» in Novosibirsk.
Pavel Filatov has become head of ITMO Collab, ITMO’s competition of interdisciplinary student projects, where the best teams receive up to 1,000,000 rubles.
Members of our team have published a paper on nanoparticles carrying microRNA-200a for treating acute and chronic liver diseases.
Konstantin Arabuli, Nikolaj Zhestkij, Lidia Mikhailova and Maria Timofeeva have completed their PhD studies. Next comes the defense of their dissertations.
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Members of our team have learned to create unclonable labels that protect goods from counterfeiting. These are images made of silicon nanoparticles formed with a laser. The color, structure and arrangement of the silicon particles cannot be controlled: these parameters are distributed randomly, which makes the label impossible to forge. To check a label for authenticity, it is enough to upload its photo to a special program that gives a verdict instantly. The results were published in ACS Applied Nano Materials.
«Imagine you have a handful of sand and decide to pour it onto a plate. As soon as the last grain falls, you will see a pattern. You will not be able to repeat the same pattern on another plate. The unclonability of our security technology is based on this principle. Instead of sand we took silicon: the laser acts on a silicon film, and nanoparticles are „knocked out“ of it and randomly form a texture. The final picture looks like a cluster of multicolored stars», says the first author of the paper, PhD student Pavel Kustov.
The technology, developed in the research group of Dmitry Zuev, senior researcher at ITMO’s New Physics and Technology Institute, is based on laser ablation, namely the transfer of a silicon film onto glass by a laser pulse. The overall shape of the label can be set in advance, for example in the shape of a brand logo. The parameters of the silicon nanoparticles that form the picture, however, cannot be programmed. Every image is unique and impossible to repeat. Silicon was chosen for a reason: compared with other substances, it is affordable, resistant to external influences and offers a wide range of colors. It can also be applied to a wider range of materials. Each silicon particle is assigned unique data: coordinates of its position and color, as well as its degree of crystallinity (structure). All these parameters are encoded and entered into a database. The position coordinates define the shape of the label and provide the first level of protection. The chromatic coordinates are responsible for the color palette and raise reliability by another step. Finally, the degree of crystallinity, the last level of protection, reflects how ordered or chaotic the atoms in each particle are. «Our labels are invisible to the naked eye. To see them and check their authenticity, you need to take a photo of the label with a magnifying lens or a microscope and upload it to a specially written program. Using machine learning and computer vision, the program aligns and clusters the photo, that is, simplifies it to a kind of paint-by-numbers picture where each number corresponds to a certain color, and then compares it with the database. If all parameters match, the program will conclude that you have the original. If there are too many differences, it will point to a fake», explains co-author Elena Petrova, a student at ITMO’s New Physics and Technology Institute. According to the authors, the labels are ideal for makers of luxury goods or products released in limited quantities: medicines, cars, jewelry, musical instruments. «There are very few studies in the international scientific community that offer affordable and easy-to-implement technologies for creating unclonable security labels. Laser ablation and silicon are used for this purpose for the first time. It turned out that a relatively simple method can provide the highest level of protection. The next step in the project is to make our labels more flexible to expand the range of materials they can be applied to», concluded co-author Martin Sandomirskii, a student.
