Browsing by Author "Fedorov, Fedor S."

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Detecting Cooking State of Grilled Chicken by Electronic Nose and Computer Vision Techniques
(2021-05-30) Fedorov, Fedor S.; Yaqin, Ainul; Krasnikov, Dmitry V.; Kondrashov, Vladislav A.; Ovchinnikov, George; Kostyukevich, Yuri; Osipenko, Sergey; Nasibulin, Albert G.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Determination of food doneness remains a challenge for automation in the cooking industry. The complex physicochemical processes that occur during cooking require a combination of several methods for their control. Herein, we utilized an electronic nose and computer vision to check the cooking state of grilled chicken. Thermogravimetry, differential mobility analysis, and mass spectrometry were employed to deepen the fundamental insights towards the grilling process. The results indicated that an electronic nose could distinguish the odor profile of the grilled chicken, whereas computer vision could identify discoloration of the chicken. The integration of these two methods yields greater selectivity towards the qualitative determination of chicken doneness. The odor profile is matched with detected water loss, and the release of aromatic and sulfur-containing compounds during cooking. This work demonstrates the practicability of the developed technique, which we compared with a sensory evaluation, for better deconvolution of food state during cooking.
Direct measurement of carbon nanotube temperature between fiber ferrules as a universal tool for saturable absorber stability investigation
(2021-10-30) Galiakhmetova, Diana; Gladush, Yuriy; Mkrtchyan, Aram; Fedorov, Fedor S.; Khabushev, Eldar M.; Krasnikov, Dmitry V.; Chinnambedu-Murugesan, Raghavan; Manuylovich, Egor; Dvoyrin, Vladislav; Rozhin, Alex; Rümmeli, Mark; Alyatkin, Sergey; Lagoudakis, Pavlos; Nasibulin, Albert G.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Single-walled carbon nanotubes (SWCNTs) are widely explored for the ultrashort pulse generation in the fiber lasers enabled by pronounced saturable absorption (SA) effect. Despite many remarkable results demonstrated in the area, degradation of the samples inside the laser cavity limits the widespread use of SWCNT-SA. In the present work, we investigate the degradation mechanism by measuring the temperature of the carbon nanotubes in an operating laser cavity in accordance with the Raman G-band position. We identify the process behind the sample degradation by comparing the burning temperature of the sample with results of thermogravimetric analysis. We apply this approach for the SWCNTs in polyvinyl alcohol polymer matrix and polymer-free SWCNT thin film and demonstrate that these samples undergo different degradation mechanism. Proposed technique provides a useful instrument for optimization of SWCNT-SA for desired ultrafast laser generation.
Evaluation of elastic properties and conductivity of chitosan acetate films in ammonia and water vapors using acoustic resonators
(2020-04-02) Zaitsev, Boris D.; Teplykh, Andrey A.; Fedorov, Fedor S.; Grebenko, Artem K.; Nasibulin, Albert G.; Semyonov, Alexander P.; Borodina, Irina A.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Novel bio-materials, like chitosan and its derivatives, appeal to finding a new niche in room temperature gas sensors, demonstrating not only a chemoresistive response, but also changes in mechanical impedance due to vapor adsorption. We determined the coefficients of elasticity and viscosity of chitosan acetate films in air, ammonia, and water vapors by acoustic spectroscopy. The measurements were carried out while using a resonator with a longitudinal electric field at the different concentrations of ammonia (100–1600 ppm) and air humidity (20–60%). It was established that, in the presence of ammonia, the longitudinal and shear elastic modules significantly decreased, whereas, in water vapor, they changed slightly. At that, the viscosity of the films increased greatly upon exposure to both vapors. We found that the film’s conductivity increased by two and one orders of magnitude, respectively, in ammonia and water vapors. The effect of analyzed vapors on the resonance properties of a piezoelectric resonator with a lateral electric field that was loaded by a chitosan film on its free side was also experimentally studied. In these vapors, the parallel resonance frequency and maximum value of the real part of the electrical impedance decreased, especially in ammonia. The results of a theoretical analysis of the resonance properties of such a sensor in the presence of vapors turned out to be in a good agreement with the experimental data. It has been also found that with a growth in the concentration of the studied vapors, a decrease in the elastic constants, and an increase in the viscosity factor and conductivity lead to reducing the parallel resonance frequency and the maximum value of the real part of the electric impedance of the piezoelectric resonator with a lateral electric field that was loaded with a chitosan film. This leads to an increase in the sensitivity of such a sensor during exposure to these gas vapors.
Exploring the performance of a functionalized CNT-based sensor array for breathomics through clustering and classification algorithms: from gas sensing of selective biomarkers to discrimination of chronic obstructive pulmonary disease
(2021-09-10) Drera, Giovanni; Freddi, Sonia; Emelianov, Aleksei V.; Bobrinetskiy, Ivan I.; Chiesa, Maria; Zanotti, Michele; Pagliara, Stefania; Fedorov, Fedor S.; Nasibulin, Albert G.; Montuschi, Paolo; Sangaletti, Luigi
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
An array of carbon nanotube (CNT)-based sensors was produced for sensing selective biomarkers and evaluating breathomics applications with the aid of clustering and classification algorithms. We assessed the sensor array performance in identifying target volatiles and we explored the combination of various classification algorithms to analyse the results obtained from a limited dataset of exhaled breath samples. The sensor array was exposed to ammonia (NH3), nitrogen dioxide (NO2), hydrogen sulphide (H2S), and benzene (C6H6). Among them, ammonia (NH3) and nitrogen dioxide (NO2) are known biomarkers of chronic obstructive pulmonary disease (COPD). Calibration curves for individual sensors in the array were obtained following exposure to the four target molecules. A remarkable response to ammonia (NH3) and nitrogen dioxide (NO2), according to benchmarking with available data in the literature, was observed. Sensor array responses were analyzed through principal component analysis (PCA), thus assessing the array selectivity and its capability to discriminate the four different target volatile molecules. The sensor array was then exposed to exhaled breath samples from patients affected by COPD and healthy control volunteers. A combination of PCA, supported vector machine (SVM), and linear discrimination analysis (LDA) shows that the sensor array can be trained to accurately discriminate healthy from COPD subjects, in spite of the limited dataset.
Flexible supercapacitors based on free-standing polyaniline/single-walled carbon nanotube films
(2022-09-01) Panasenko, Iurii V.; Bulavskiy, Mikhail O.; Iurchenkova, Anna A.; Aguilar-Martinez, Yenanny; Fedorov, Fedor S.; Fedorovskaya, Ekaterina O.; Mikladal, Bjørn; Kallio, Tanja; Nasibulin, Albert G.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Advances in supercapacitor performance are boosted both by material design helping to improve specific capacitance and by tailoring of device architecture, often addressing flexibility to enable rolling-up packaging to reach high nominal values. This keeps attention to flexible lightweight materials, such as single-walled carbon nanotubes (SWCNTs), and conducting polymers, such as polyaniline (PANI). In this work, we design and study unique “dead-weight” free supercapacitors based on PANI electrochemically deposited on free-standing SWCNT films. Depending on the carbon nanotube film characteristics, we adjusted polymer inclusion into the nanotube films and evaluated its structure by TEM, SEM, XPS and Raman spectroscopy. Electrochemical methods were used to investigate the relationship between the morphology of initial SWCNT films, deposited PANI, and the electrochemical properties of the composite materials, including specific gravimetric capacitance and self-discharge processes. We show that thin free-standing films of SWCNTs with deposited PANI are less prone to self-discharge due to higher resistance arising from the lower density of the nanotubes in the film. Yet, such films enable better and more uniform deposition allowing to reach the maximum gravimetric capacitance value of 541 F g−1. This synergistic performance allows the creation of an electrode material for flexible ultra-light and powerful supercapacitors.
Green Lithography for Delicate Materials
(2021-07-02) Grebenko, Artem; Bubis, Anton; Motovilov, Konstantin; Dremov, Viacheslav; Korostylev, Evgeny; Kindiak, Ivan; Fedorov, Fedor S.; Luchkin, Sergey; Zhuikova, Yuliya; Trofimenko, Aleksandr; Filkov, Gleb; Sviridov, Georgiy; Ivanov, Andrey; Dull, Jordan T.; Mozhchil, Rais; Ionov, Andrey; Varlamov, Valery; Rand, Barry P.; Podzorov, Vitaly; Nasibulin, Albert G.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
A variety of unconventional materials, including biological nanostructures, organic and hybrid semiconductors, as well as monolayer, and other low-dimensional systems, are actively explored. They are usually incompatible with standard lithographic techniques that use harsh organic solvents and other detrimental processing. Here, a new class of green and gentle lithographic resists, compatible with delicate materials and capable of both top-down and bottom-up fabrication routines is developed. To demonstrate the excellence of this approach, devices with sub-micron features are fabricated on organic semiconductor crystals and individual animal's brain microtubules. Such structures are created for the first time, thanks to the genuinely water-based lithography, which opens an avenue for the thorough research of unconventional delicate materials at the nanoscale.
High Performance Hydrogen Evolution Reaction Catalyst Based on Single-Walled Carbon Nanotubes Decorated by RuOx Nanoparticles
(2020-06-17) Fedorov, Fedor S.; Settipani, Daniel; Melandsø Buan, Marthe Emelie; Sainio, Jani; Ali, Farhan S.M.; Ilatovskii, Daniil; Kallio, Tanja; Nasibulin, Albert G.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
We report a cathode material based on plasma-treated single-walled carbon nanotubes decorated by RuOx nanoparticles using atomic layer deposition. We have examined cathode performance towards hydrogen evolution reaction by tailoring material wettability, conductivity yielded by plasma treatment, and the catalyst loading. We discuss that nucleation of particles is facilitated by the appearance of carboxylic and hydroxyl groups triggered by oxygen plasma action. The best performance is associated with samples containing RuOx particles of 4–5 nm, which show hydrogen evolution onset potential to be about −5 mV (vs. RHE) in 0.5 M H2SO4 measured at a current density of −1 mA cm−2 and Tafel slope of 47.5 mV/dec. The material possesses stable performance at −10 mA cm−2 with a potential of about −160 mV.
Highly efficient bilateral doping of single-walled carbon nanotubes
(2021-04-07) Goldt, Anastasia E.; Zaremba, Orysia T.; Bulavskiy, Mikhail O.; Fedorov, Fedor S.; Larionov, Konstantin V.; Tsapenko, Alexey P.; Popov, Zakhar I.; Sorokin, Pavel; Anisimov, Anton S.; Inani, Heena; Kotakoski, Jani; Mustonen, Kimmo; Nasibulin, Albert G.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
A boost in the development of flexible and wearable electronics facilitates the design of new materials to be applied as transparent conducting films (TCFs). Although single-walled carbon nanotube (SWCNT) films are the most promising candidates for flexible TCFs, they still do not meet optoelectronic requirements demanded for their successful industrial integration. In this study, we proposed and thoroughly investigated a new approach that comprises simultaneous bilateral (outer and inner surface) SWCNT doping after their opening by thermal treatment at 400 °C under an ambient air atmosphere. Doping by a chloroauric acid (HAuCl4) ethanol solution allowed us to achieve the record value of equivalent sheet resistance of 31 ± 4 Ω sq-1 at a transmittance of 90% in the middle of the visible spectrum (550 nm). The strong p-doping was examined by open-circuit potential (OCP) measurements and confirmed by ab initio calculations demonstrating a downshift of the Fermi level of around 1 eV for the case of bilateral doping.
In vitro toxicity of carbon nanotubes: a systematic review
(2022-05-31) Chetyrkina, Margarita R.; Fedorov, Fedor S.; Nasibulin, Albert G.
A2 Katsausartikkeli tieteellisessä aikakauslehdessä
Carbon nanotube (CNT) toxicity-related issues provoke many debates in the scientific community. The controversial and disputable data about toxicity doses, proposed hazard effects, and human health concerns significantly restrict CNT applications in biomedical studies, laboratory practices, and industry, creating a barrier for mankind in the way of understanding how exactly the material behaves in contact with living systems. Raising the toxicity question again, many research groups conclude low toxicity of the material and its potential safeness at some doses for contact with biological systems. To get new momentum for researchers working on the intersection of the biological field and nanomaterials, i.e., CNT materials, we systematically reviewed existing studies with in vitro toxicological data to propose exact doses that yield toxic effects, summarize studied cell types for a more thorough comparison, the impact of incubation time, and applied toxicity tests. Using several criteria and different scientific databases, we identified and analyzed nearly 200 original publications forming a “golden core” of the field to propose safe doses of the material based on a statistical analysis of retrieved data. We also differentiated the impact of various forms of CNTs: on a substrate and in the form of dispersion because in both cases, some studies demonstrated good biocompatibility of CNTs. We revealed that CNTs located on a substrate had negligible impact, i.e., 90% of studies report good viability and cell behavior similar to control, therefore CNTs could be considered as a prospective conductive substrate for cell cultivation. In the case of dispersions, our analysis revealed mean values of dose/incubation time to be 4-5 μg mL−1 h−1, which suggested the material to be a suitable candidate for further studies to get a more in-depth understanding of its properties in biointerfaces and offer CNTs as a promising platform for fundamental studies in targeted drug delivery, chemotherapy, tissue engineering, biosensing fields, etc. We hope that the present systematic review will shed light on the current knowledge about CNT toxicity, indicate “dark” spots and offer possible directions for the subsequent studies based on the demonstrated here tabulated and statistical data of doses, cell models, toxicity tests, viability, etc.
Multifunctional Elastic Nanocomposites with Extremely Low Concentrations of Single-Walled Carbon Nanotubes
(2022-04-27) Novikov, Ilya V.; Krasnikov, Dmitry V.; Vorobei, Anton M.; Zuev, Yaroslav I.; Butt, Hassaan A.; Fedorov, Fedor S.; Gusev, Sergey A.; Safonov, Alexander A.; Shulga, Eugene V.; Konev, Stepan D.; Sergeichev, Ivan V.; Zhukov, Sergey S.; Kallio, Tanja; Gorshunov, Boris P.; Parenago, Olga O.; Nasibulin, Albert G.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Stretchable and flexible electronics has attracted broad attention over the last years. Nanocomposites based on elastomers and carbon nanotubes are a promising material for soft electronic applications. Despite the fact that single-walled carbon nanotube (SWCNT) based nanocomposites often demonstrate superior properties, the vast majority of the studies were devoted to those based on multiwalled carbon nanotubes (MWCNTs) mainly because of their higher availability and easier processing procedures. Moreover, high weight concentrations of MWCNTs are often required for high performance of the nanocomposites in electronic applications. Inspired by the recent drop in the SWCNT price, we have focused on fabrication of elastic nanocomposites with very low concentrations of SWCNTs to reduce the cost of nanocomposites further. In this work, we use a fast method of coagulation (antisolvent) precipitation to fabricate elastic composites based on thermoplastic polyurethane (TPU) and SWCNTs with a homogeneous distribution of SWCNTs in bulk TPU. Applicability of the approach is confirmed by extra low percolation threshold of 0.006 wt % and, as a consequence, by the state-of-the-art performance of fabricated elastic nanocomposites at very low SWCNT concentrations for strain sensing (gauge factor of 82 at 0.05 wt %) and EMI shielding (efficiency of 30 dB mm-1at 0.01 wt %).
Novel design strategy for GaAs-based solar cell by application of single-walled carbon nanotubes topmost layer
(2020-08-01) Mitin, Dmitry M.; Bolshakov, Alexey D.; Neplokh, Vladimir; Mozharov, Alexey M.; Raudik, Sergei A.; Fedorov, Vladimir V.; Shugurov, Konstantin Yu; Mikhailovskii, Vladimir Yu; Rajanna, Pramod M.; Fedorov, Fedor S.; Nasibulin, Albert G.; Mukhin, Ivan S.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Attempts to improve solar cells efficiency touch all its constituents and are directly related to their fabrication protocols. While the most promising material platform for high efficiency photovoltaic devices is still III-V semiconductors, introduction of novel materials like single-walled carbon nanotubes (SWCNTs), which are characterized by unique combination of conductivity and transparency, might greatly yield the device performance. Here, for the first time, we present the results of the fabrication and characterization of a thin-film GaAs solar cell with a SWCNT top contact. We examine the contact between the SWCNT film and the semiconductor structure by means of the optical and electron beam-induced current techniques. The fabricated device demonstrates better performance, that is, increased power conversion efficiency from 10.6% to 11.5% when compared to the cell with the traditional metal contact grid, stemming from the enhanced photocurrent collection efficiency and low parasitic light absorption in the emitter layer. We envision future prospects to exploit the multifunctionality of the SWCNTs in fabrication of highly efficient photovoltaic devices including flexible solar cells.
Quantum of selectivity testing: detection of isomers and close homologs using an AZO based e-nose without a prior training
(2022-04-12) Goikhman, Boris; Fedorov, Fedor S.; Simonenko, Nikolay P.; Simonenko, Tatiana L.; Fisenko, Nikita A.; Dubinina, Tatiana S.; Ovchinnikov, George; Lantsberg, Anna; Lipatov, Alexey; Simonenko, Elizaveta P.; Nasibulin, Albert G.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Tracing the chemical composition of the surrounding environment appeals to the design of highly sensitive and selective gas sensors. Primarily driven by IoT, miniaturized multisensor systems, like e-noses, are considered to address both selectivity and sensitivity issues. Although e-noses might enable discrimination between close homologs and isomers, they are required to be "trained", i.e. to project analyte-related signals into artificial space, prior to their in-field applications. In this study, using the programmed co-precipitation method, we synthesized aluminum-doped zinc oxide (AZO) and employed it as a sensing material in an e-nose to examine the sensing performance towards close C1-C5 alcohol homologs and isomers, e.g. 1-propanol and 2-propanol, 1-butanol and isobutanol in the frame of the multisensor paradigm. For the first time, we demonstrated selective recognition of the alcohol vapors without prior training of the e-nose. This was realized by matching projections of the known analytes' "fingerprints", used to build a chemical space, with the projections of analyte-related signals acquired using the e-nose in artificial space under machine learning algorithms. Moreover, the AZO based e-nose demonstrates a remarkable, up to 0.87, chemoresistive response to alcohol vapors, 0.9 ppm, in the mixture with air at 300 degrees C with a detection limit down to sub-ppb level. This opens a new avenue for the development of self-learning gas analytical systems, which might recognize new analytes whose profiles are not yet stored in their library.
Quasi-2D Co3O4 nanoflakes as an efficient gas sensor: versus alcohol VOCs
(2020-04-21) Fedorov, Fedor S.; Solomatin, Maksim A.; Uhlemann, Margitta; Oswald, Steffen; Kolosov, Dmitry A.; Morozov, Anatolii; Varezhnikov, Alexey S.; Ivanov, Maksim A.; Grebenko, Artem K.; Sommer, Martin; Glukhova, Olga E.; Nasibulin, Albert G.; Sysoev, Victor V.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Here, we study quasi-two-dimensional crystals of Co3O4 grown by electrochemical synthesis on Pt electrodes with a nanoflake morphology to serve as a gas sensor. When synthesizing in aqueous electrolytes under applied electrical bias, the material follows a self-hierarchical architecture to primarily appear as the hexagonal nanoflakes α-Co(OH)2. After heating up to 300 °C in air, the as-synthesized material transforms to Co3O4, preserving the original hierarchical morphology. The Co3O4 nanoflakes have been found to have remarkable chemiresistive response when exposed to various kinds of alcohol vapors, at low ppm concentrations in a mixture with air, over a wide range of temperatures up to 300 °C with a detection limit down to the ppb range with direct dependence on the molecule weight of the alcohol. We explain the observed features of the gas response of the Co3O4 nanoflakes by a shift in the electron density under the chemisorption of VOCs, verified by DFT calculations.
The room-temperature chemiresistive properties of potassium titanate whiskers versus organic vapors
(2017-12-19) Varezhnikov, Alexey S.; Fedorov, Fedor S.; Burmistrov, Igor N.; Plugin, Ilya A.; Sommer, Martin; Lashkov, Andrey V.; Gorokhovsky, Alexander V.; Nasibulin, Albert G.; Kuznetsov, Denis V.; Gorshenkov, Michail V.; Sysoev, Victor V.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
The development of portable gas-sensing units implies a special care of their power efficiency, which is often approached by operation at room temperature. This issue primarily appeals to a choice of suitable materials whose functional properties are sensitive toward gas vapors at these conditions. While the gas sensitivity is nowadays advanced by employing the materials at nano-dimensional domain, the room temperature operation might be targeted via the application of layered solid-state electrolytes, like titanates. Here, we report gas-sensitive properties of potassium titanate whiskers, which are placed over a multielectrode chip by drop casting from suspension to yield a matrix mono-layer of varied density. The material synthesis conditions are straightforward both to get stable single-crystalline quasi-one-dimensional whiskers with a great extent of potassium replacement and to favor the increase of specific surface area of the structures. The whisker layer is found to be sensitive towards volatile organic compounds (ethanol, isopropanol, acetone) in the mixture with air at room temperature. The vapor identification is obtained via processing the vector signal generated by sensor array of the multielectrode chip with the help of pattern recognition algorithms.
Tailoring electrochemical efficiency of hydrogen evolution by fine tuning of TiO x /RuO x composite cathode architecture
(2019-04-23) Fedorov, Fedor S.; Vasilkov, Mikhail Y.; Panov, Maxim; Rupasov, Dmitry; Rashkovskiy, Alexander; Ushakov, Nikolay M.; Lee, Jaeho; Hempelmann, Rolf; Kallio, Tanja; Nasibulin, Albert G.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Here we report an approach to design composite cathode based on TiO x nanotubes decorated with RuO x nanowhiskers for efficient hydrogen evolution. We tailor catalytic activity of the cathodes by adjustment of morphology of TiO x nanotubular support layer along with variation of RuO x loaded mass and assess its performance using electrochemical methods and wavelet analysis. The highest energy efficiency of hydrogen evolution is observed in 1 M H 2 SO 4 electrolyte to be ca. 64% at −10 mA/cm 2 for cathodes of the most developed area, i.e. smaller diameter of tubes, with enhanced RuO x loading. The efficiency is favored by detachment of small hydrogen bubbles what is revealed by wavelet analysis and is expressed in pure noise at wavelet spectrum. At increased current density, −50 or −100 mA/cm 2 , better efficiency of composite cathodes is supported by titania nanotubes of larger diameter due to an easier release of large hydrogen bubbles manifested in less periodic events appeared in the frequency region of 5–12 s at the spectra. We have shown that efficiency of the catalysts is determined by a pre-dominant type of hydrogen bubble release at different operation regimes depending on specific surface and a loaded mass of ruthenia.
The Ti wire functionalized with inherent TiO2 nanotubes by anodization as one-electrode gas sensor: A proof-of-concept study
(2020-03-01) Lashkov, Andrey V.; Fedorov, Fedor S.; Vasilkov, Mikhail Yu; Kochetkov, Alexey V.; Belyaev, Ilia V.; Plugin, Ilia A.; Varezhnikov, Alexey S.; Filipenko, Anastasia N.; Romanov, Stepan A.; Nasibulin, Albert G.; Korotcenkov, Ghenadii; Sysoev, Victor V.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
We propose a Ti wire functionalized with inherent anatase TiO2 nanotubes by an anodization process to serve as a one-electrode gas sensor. The design is similar to other known one-electrode gas sensors when the wire is employed both as a heater and measuring resistive element. We discuss the low-cost fabrication protocol, the structure of the sensor characterized by Raman spectroscopy and electron microscopy, and show the proof-of-concept sensor responses to a few organic vapors, acetone and alcohols, in mixture with air. We have found the response-to-concentration curves to follow a linear fit with a detection limit below 1000 ppm. These findings enlarge the range of possible gas sensor architectures based on nanostructured material for research and practical applications.