Synthesis of Education, Science and Production: Practical Experience
The laboratory not only solves the educational problems, it co-operates with many academic and research organizations, for example, with the Institute of Element Organic Compounds of RAS (INEOS RAS), Institute of Chemical Physics of RAS, Institute of Synthetic Polymeric Materials of RAS, Scientific Research Institute of Epidemiology and Microbiology.
"We carry out projects in different spheres, we investigate the most varied objects – from biological ones, for example, bacterial cells, up to graphite, graphene, carbon nanotubes and polymers, – says Olga Sinitsyna, scientific employee of HMC Chair of the Chemical Faculty of the Moscow State University. – By means of a probe it is possible not only to scan, but also to change a material’s structure, therefore SPM is also used for development of new systems". Together with the Scientific Research Institute of General Resuscitation of the Russian Academy of Medical Sciences the employees of the laboratory investigated red blood cells, in particular, the processes of electroporation of cells. Jointly with the Institute of Radio Engineering and Electronics and within the framework of the project on creation of electromechanical nanoactuators, the materials with memory shape effect were investigated. From such a material, in particular, a nano-sized cantilever was made. Also tens of other projects have been realized.
The laboratory has modern measuring devices and is incorporated into the structure of Bionanoscopy Center of collective usage. Its basic measuring equipment includes FemtoScan scanning probe microscopes of different modifications, which were developed and produced by Advanced Technologies Center (www.nanoscopy.ru). In each device more than 50 various modes of scanning probe microscopy are realized, including practically all kinds of the atomic-force microscopy, the scanning frictional microscopy, scanning tunnel microscopy, the tunnel spectroscopy, the scanning resistive microscopy, etc. Measurements can be done in the air or in liquids with adjustable heating of a sample. The laboratory has also FemtoScan Cryo model with a possibility of carrying out of researches at temperatures from 5 up to 350 K.
SPM allows us to obtain atomic resolutions on the materials, inert in the air, for example, mica and graphite. It is possible to investigate separate molecules. According to the laboratory employees, one of the important advantages of FemtoScan microscope in comparison with its foreign analogues is a possibility of introduction of additions into its design, creation of various superstructures for working out of new techniques of measurement and behavior of various experiments. Olga Sinitsyna tells: "Since we are closely connected with the company-manufacturer, experiments with the device are encouraged. For example, in one of the students’ projects an atomic-force microscope was combined with an interferometer – with the help of the latter the specific points of a crystal for a subsequent research by means of AFM were determined. The direction of cantilever sensor controls is also being developed – on the basis of SPM cantilevers students and post-graduate students develop devices, which allow us to define various chemical substances.
The laboratory’s employees participated in development of a scientific-educational program on nanotechnologies, which included a course of scanning probe technology. The project was implemented jointly with the Fund for Infrastructure and Educational Programs. The program employed actively FemtoScan Online software, which ensures a remote control for the microscope. The developed educational module allows us to master the basic modes of operation of the scanning probe microscopes in a remote way and to get experimental data from any point in the world. Control over implementation of the works during remote training was organized through a web-interface, while the basic part of the experimental work was done with the help of the software of client-server architecture. The program was tested and highly appraised.
According to the laboratory employees, the option of a remote access is convenient both for training and for the research works. Olga Sinitsyna: "Scanning can be done slowly, therefore, if there is no time to wait, the device can be left to work autonomously, and its operation can be remote-controlled. Besides, when there are many people indoors, additional acoustic noise and vibrations appear, which influence negatively the quality of the obtained images. The air can be warmed up by several degrees, and if the temperature of a sample is not additionally stabilized, a drift of the sample’s surface occurs. A bigger drift can make a probe lose its contact with the surface. The problem can be solved, if we leave a device in an empty premise and operate it in a remote way".
Possibility of a remote access is convenient for adjustment of equipment for inexperienced users and for carrying out of presentations at exhibitions and conferences. In the latter case a device does not have to be transported, it can be demonstrated with the help of a web camera placed nearby.
Our own know-how and techniques
SPМ is recommended to be placed in the ground floors, because the buildings’ vibrations cause considerable hindrances. This is one of the reasons why it is often inexpedient to transport the device to the outside events, which leaves only a chance of a remote demonstration of its potentials. The basic premise of the laboratory is located on the first floor. "We do not use an active vibrodamping, but we have our own know-how – special supports", – said Anastasia Bolshakova, senior scientific employee of the HMC Chair of the Chemical Faculty of the Moscow State University. However, experience of the laboratory employees shows, that FemtoScan is steady enough against vibrations and hindrances. Olga Sinitsyna: "At several exhibitions we got convinced, that if not angstrom than nanometer resolutions can be obtained, even in difficult conditions when the device is not protected from the noise and influence of other external factors".
Research techniques are selected for a concrete object. Anastasia Bolshakova: "For typical objects the techniques are adjusted in the educational processes, in particular, in laboratory works. If it is a new object, in the beginning we try the available techniques, then we study publications, but descriptions there are often superficial, because many authors try to hide a part of information".
Sample preparation and other problems
Basically experiments are carried out in the air, because researches in a liquid demand a much more labor-consuming sample preparation. Olga Sinitsyna: "Understandable is a desire to get interesting results with minimal labor costs, but work with many objects, for example biological ones, requires difficult sample preparation. Probe microscopy shows topography, but it is not always easy to determine a chemical compound. Certainly, if the thermomechanical properties or electric conductivity of different elements of a surface differ, we can distinguish these areas. If the properties of the surface elements are close, the contrast will be insignificant. In such cases a correct sample preparation is especially important, for example etching of a sample».
Also, according to the laboratory employees, problems arise because of negligence in sample preparation and a prejudiced attitude to the results. Georgy Meshkov: "Very often the people, who bring samples, wish to see what they wish instead of an objective picture".
New method of measurements
One of the laboratory’s recent developments jointly elaborated with Skolkovo company Medical Nanotechnologies is the scanning ion-conducting microscopy, allowing us to study cells with a soft membrane, objects with a flexible cover and jelly-like samples. A scanning is carried out in an electrolyte solution, at that, a sample itself may be not conducting. Instead of a cantilever, a nanocapillary is used with diameter of aperture of about 10 nm, inside of which there is an electrode. Between the electrode in a capillary and the electrode placed in a solution the ion current flows. If the open tip of the nanocapillary comes nearer to the sample, than, beginning from a certain distance, approximately equal to the diameter of the nanocapillary, the current decreases, which allows us to receive a surface image.
During research of biological samples, for example, live cells, the new method provides opportunity to investigate the structure of their surface in an unstrained state. The tip of the nanocapillary can be immersed into a cell for studying of the electrochemical processes, which are going in it. This technology is planned to be developed, so that in future it will be realized in serial devices of the innovative companies Advanced Technologies Center and Medical Nanotechnologies (www.nanotomed.com). High-speed operating control electronics was also developed for these purposes. Now a feedback system can work on frequency of 1 MHz. Thus, not only the speed of measurements is raised, but also the quality of the obtained images, which is especially important for studying of the complex biological systems. ■