BULGARIAN SCIENCE FUND
Grant № КП-06-Н37/7
Principal Investigator: assoc. prof. Dr. Karekin Esmeryan
Title of the research: Studying the impact of physicochemical characteristics of super non-wetting carbon soot coatings on their icephobic properties
Duration: 12.2019 – 12.2022
This research project incorporates the latest developments in engineering, physics and chemistry with new insights into the droplet impact and heat/mass transfer phenomena in order to clarify the fundamental reasons behind the different anti-icing performances of super non-wettable coatings with variable physicochemical profile (structure, morphology, roughness, thickness, surface chemistry, etc).
Contract No КП-06-Н38/6
Topic: Magnetic quantum effects in low-dimensional and nanostuctured spin systems
Coordinator: Hassan Chamati, Prof. DSc
Duration: 12.2019 – 12.2022
The main aim of the current project is to investigate the basic physical mechanisms, taking place in nanostructured magnets due to the interplay of quantum and thermal effects from one hand and the confinement due to finite nano-sizes from the other. We will focus our efforts on gaining insights into the fundamental physical processes in spin systems, accommodated to the investigation of novel magnetic mow-dimensional and nanomaterials. In the framework of this project the members of the scientific team will concentrate their attention on the consideration of systems accounting for various supplementary spin variables, charge and other degrees of freedom, that would lead to novel quantum phases and excitations. The main task of the project is to unveil the role of important physical parameters, controlling the correlation among the different magnetic structures and symmetries of well established macroscopic states and low-lying excitations. The theoretical approach to be used include, among other, a set of standard manybody methods, such as spin-wave expansion, Green functions, effective Hamiltonian and variation wave functions. Other tools to be used are based a modern techniques, such as Unsupervised learning in the frames of the Restricted Bolzmann Machunes.
Contract No КП-06-Н37/2
Topic: Basic research and development of high-beam-quality high-power laser system oscillating in visible spectral range
Coordinator: Georgi Yankov, Assistant prof. PhD
Duration: 12.2019 – 12.2022
Basic research objectives are: 1) To research and develop high-power high-beam quality copper bromide (CuBr) and copper (Cu) vapour laser system, oscillating on Cu atomic self-terminating transitions in the visible spectral range; 2) To carry out basic research on interaction of 510.6- and 578.2-nm laser radiation with various materials.
For a successful implementation of the basic research objectives, it is planned to accomplish the following scientific tasks: 1) To research and develop high-power CuBr vapour laser with superior average output power for this laser class; 2) To research and develop master oscillator-powerful amplifier (MOPA) system with high-beam quality reaching the diffraction limit and with high flux of the average laser power density in the range of TW.cm-2; 3) To study experimentally and theoretically the interaction of laser radiation at the 510.6- and 578.2-nm Cu atomic lines with different materials, such as metals and their alloys, ceramics, glasses, biological tissues, etc.
For the accomplishment of the planned tasks modern experimental and theoretical methods will be used, including development and utilization of new ones.
Expected scientific results can be summarized, as follows: 1) Obtaining of laser oscillation in the visible spectral region with average output power of 150-200 W and beam divergence reaching diffraction limit; 2) Determination of the optimal laser parameters at irradiation of various materials.
Contract No КП-06-Н38/5
Topic: Functionalization of 3D printed fibrous scaffolds via femtosecond laser patterning
Coordinator: Ekaterina Iordanova, Assoc.prof. PhD
Duration: 12.2019 – 12.2022
The relevance of the topic in the proposed project can be foreseen in two aspects – the first based on the proposed innovative biomaterials, the second one on the method for the determination and characterization of their morphological and topographic properties by femtosecond laser microstructuring.
At present, biopolymers (collagen, gelatin, chitosan, etc.) and polymers such as poly-ε-caprolactine (PLC), poly-l-lactide (PLLA), polydimethysiloxane (PDMS), polymethylmethacrylate PLGA and etc) are widely used in applications for tissue engineering as a basic material for tissue implant structures. Most of the synthetic polymers have good mechanical properties but lack the biological natural function of natural biopolymers. Synthetic polymers are widely used as they can be easily synthesized with desired geometry and composition.
The use of laser methods for treatment of biopolymer surfaces is a promising alternative compared to existing chemical methods. The advantages of the proposed scientific approach are mainly determined by the use of femtosecond laser iradiation to create microstructures with improved bioactivity of biomaterials used in tissue engineering. Femtosecond laser modification offers minimal impact of thermal effects, precise and controlled modification of desired areas, contactless interaction of laser iradiation characterized by high reproducibility, not requiring the use of chemical agents. The mechanical properties of the material after the laser impact remain unchanged. However, many fundamental aspects between cell viability and the properties of the laser-modified structures are not yet fully understood.
The main scientific objectives in the present project are:
• Synthesis of thin biopolymer layers and 3D printed polymer scaffolds with a particular application in tissue engineering
• Microstructuring on surface and in volume of the new synthesized samples by precisely controlled and reproducible parameters of the femtosecond laser irradiation (laser fluence, number of pulses, wavelength region).
• Description of the morphology and 3D topography of the treated biomaterials, as well as the impact of different laser operating parameters. Analyses of their chemical, physical and mechanical characterization.
In order to achieve the scientific objectives, thin biopolymer layers will be synthesized according to established protocols. The synthesis of 3D matrices will be accomplished by 3D polymer printing technology. The laser treatment of newly synthesized specimens will be performed by a femtosecond Ti:sapphire laser with a pulse duration of 35 fs. Optical, morphological and chemical analyzes will be analyzed by modified z-scan method, SEM, AFM, FTIR Fluorescence Confocal Microscopic Analysis and others.
The realization of such a methodology will enable effective determination and application of the specific properties of 3D biopolymer materials. These materials have the potential to be used both for obtaining the desired implant structures and for creating new technologies in the field of bioengineering and biomedicine. Successful implementation and dissemination of the project will be a prerequisite for attracting the interest of both scientific and industrial organizations.
Contract No КП06-Н28-9-2
Topic: Effects of resistive switching and magneto resistance in transition metal (Co, Ni, Fe) doped ZnO layers for multifunctional applications
Coordinator: Prof. DSc. Albena Paskaleva
Duration: 12.2018 – 12.2021
The wide spread in the recent years of portable digital devices defined the significant interest of the semiconductor industry to non-volatile memory (NVM) technology. Novel memory concepts totally different from that based on charge-storage are especially attractive for the next-generation nonvolatile memories. Resistive random access memory (ReRAM) is considered as one of the most promising candidates among them because it offers some attractive advantages in respect to the floating gate technology. Magnetic memories based on magnetoresistance effect are another very intensively investigated concept for realization of “non-charge” based storage devices. Further important step in the process of enhancing the data storage densities is the realization of multifunctional device, i.e. simultaneous electrical tuning of multiple physical properties. A realistic approach to meet the demands is the electrical control of the magnetic and resistance properties which is of great interest not only for technological applications but also for fundamental physics. It is a great challenge for simultaneous realization of large memristance and magnetoresistance in one nanoscale junction, because it is very hard to find a proper layer which not only serves as good insulating layer for magnetoresistance but also easily switches between high and low resistance states under electrical field. In addition, this device should operate at room temperature which is additional challenge what concerns magnetoresistive effect. The purpose of the project is to obtain by atomic layer deposition (ALD) ZnO films doped with different 3d transition metal elements (Co, Ni, Fe) as possible materials for application in multifunctional memory and sensor devices. Resistive switching effects, magnetic properties and magnetoresistance will be systematically studied in dependence on dopant, structure and process parameters. The project aims at in-depth analysis and understanding of fundamental processes and phenomena at the origin of RS and magnetoresistance in doped ZnO layers and their intimate interplay. The ultimate goal is to elaborate Metal/ZnO-based/Metal structures where the materials are developed and optimized to stabilize simultaneous resistive switching and magnetoresistance at room temperature and the system behaves as a memristor, in which the state variable is the magnetic moment in addition to the resistance.
Contract No ДН08-7/13.12.2016
Topic: Mechanical and electrical properties of model lipid membranes in the presence of biologically active substances
Coordinator: Assoc. Prof. Victoria Vitkova, PhD
The understanding of basic mechanisms driving some vital processes in biological cells requires a detailed knowledge of mechanics and electrostatics of biomembranes. The main objective is to first establish concerted and multifaceted investigation of these properties using a set of model lipid membranes and applying complementary techniques (fluctuation analysis on lipid vesicles, electrochemical impedance spectroscopy on planar lipid bilayers, etc.), and second, to evaluate how these properties are affected by biochemically relevant molecules. Synthetic bilayers will be studied in the presence of substances of practical importance for the pharmacology and food industry. The successful accomplishment of the research project will produce new scientific knowledge on the mechanical and electrical properties of biomimetic model systems as a result of combining a multidisciplinary approach, extensive scientific expertise and advanced methodology.
Contract No ДН08-2/13.12.2016 г.
Topic: Liquid crystal approach for model lipid membrane functions optimization by nanoparticles insertion
Coordinator: Assoc. prof. PhD Julia Genova
In the present project we plan experimental and theoretical investigations of the properties of lipid molecular aggregates by inclusions of organic and non-organic nano-particles and bio active molecules. The role of the hydrogen bonds for stabilization the structure and the functions of the provoked by the inclusions complex liquids, in particular lipid membranes and dimeric liquid crystals, will be studied. The resemblance of the lipid membranes (with long range liquid crystal order) and the dimeric liquid crystals, determines by the availability of the nets of the hydrogen bonds in the two systems. This fact premises the liquid crystal approach, for theoretical interpretation of the lipid membrane experimental data, to be applied. The project implementation will be realized by specialists on structural and electrooptical properties of the liquid crystals, including dimeric liquid crystals and their nanocomosites, in collaboration with specialists on structural and physical properties of the bi-layer lipid membranes and vesicules. The basic organization of the project posses the necessary for the implementation of the project experimental base and corresponding infra structure. Unique experimental sets and technologies for the investigation of the mechanical properties of the bi-layer lipid membranes are available. The signification of the hydrogen bond for the mechanical properties of the lipid membrane is one of the expected results. The training up of the young scientists, included in the project, will be one of the basic tasks.
Contract No ДН08-16/14.12.2016
Topic: “Laser induced fabrication of three dimensional nanoparticle structures and study of their optical properties”
Coordinator: Ekaterina Iordanova
Duration: 12.2016 – 12.2019
The presented research project is focused on the fundamental physical background of a laser assisted method for fabrication of noble metal nanoparticles into transparent materials and study of the optical properties of complex nanoparticle structures. The main activities are directed to the revealing of the mechanisms of laser-composite materials interaction and laser induced complex nanoparticles structure formation. The main activities in the presented project are directed to study of the fundamentals of a method for fabrication of complex 3D nanoparticle systems embedded into dielectric matrixes. The method is based on photo induced reduction of metal ions embedded into silicate glasses. The main objects of interest are the mechanisms playing role in the particle formation and dynamics and the influence of the processing conditions. This knowledge will give opportunity of fabrication of structures with desired and controllable characteristics. The well developed methods for 3D laser scanning will turn this method into a high efficient in fabrication of complex composite materials that has no alternatives at the present. The formation of such materials will facilitate the experimental study of their optical properties, the description of the mechanisms of interaction of such systems with the electromagnetic field and the characteristics of the field in their near field zone.
Contract No ДН 18/14 – 12.12.2017
Topic: Composite and adiabatic methods for control in quantum and optical technologies
Coordinator: Assoc. Prof. Dr. Emiliya Dimova, PhD
Duration: 12.2017 – 12.2020
The present project is dedicated on the development of new methods for coherent control of quantum states on the samples of ultra-cold atoms and on the application of the laws of quantum physics in classical optics for the creation of new technologies. The successful realization of the project is guaranteed by the close collaboration between both teams: the theoretical team developing the basic methods and experimental team with good expertise in the implementation of the proposed new methods. Moreover, through this project the research groups from different scientific institutions is consolidated. This enables the exchange of knowledge, technology and equipment. As a result, It leads to improving the qualifications of the team members and the project attracted more students and PhD students. Theoretical methodology involves several basic methods of theoretical and mathematical physics that allow analytical and numerical description of discrete quantum systems. It covers areas such as: classical and quantum optics, quantum coherent control metamaterials, nonlinear optics, etc. The experimental realizations is based on the manipulation of coherent states of rubidium atoms, cooled to tens of micro-kelvin, and the realization of new optical components. New methods of coherent control of quantum states of atoms will be produced. New methods for the realization of optical devices, for example broadband optical components, will be molded.
Cooperation project between the Institute of Solid State Physics – the Bulgarian Academy of Sciences, Sofia, Bulgaria and the Joint Institute for Nuclear Research (JINR), Dubna, Russian Federation
Тема: Investigation of the influence of nanoparticles on the properties of biologically relevant systems
Ръководител: Assoc. prof. PhD Julia Genova
In the present project we plan experimental and theoretical investigations of the physical and structural properties of biologically relevant systems and modification of these properties by incorporation of organic and non-organic nano-particles and bio active molecules, including carbon nanostructures, cholesterol, proteins and others. Typical structural methods for studying the specific physical characteristics properties of complex systems involving Fourier transform infrared (FT-IR), polarization micro-Raman spectroscopy, differential scanning calorimetry (DSC), thermally induced shape fluctuations analysis (TISFA), atomic-force microscopy (AFM) will be used. The evaluation of the standard physical parameters, like enthalpy, energy, entropy gives us possibility to apply molecular dynamic simulation for assignment of the new physical and structural characteristics of the complex lipid systems. The project implementation will be realized by specialists on mechanical and structural properties of bilayer lipid membranes and vesicles, structural and electrooptical properties of condensed matter, with specialists on computer modelling.