Researchers of the Department of Microelectronics and Biomedical Engineering of the Faculty of Computer Science, Informatics and Microelectronics, Vasile POSTICA, PhD student, third year, winner of the BCR scholarship “Bursa Speranței” (2017) and of the nominal scholarship “Sergiu Rădăuţan” (2018-2019) of the Government of Moldova, under the guidance of univ. prof. dr. hab. Oleg LUPAN, director of the Center for Nanotechnologies and Nanosensors, UTM, in collaboration with scientists from AȘM, University of Kiel, Germany, Hamburg University of Technology, Germany, and the Institute of Solid State Physics, Friedrich-Schiller-Universität Jena, Germany, designed, manufactured and researched a nanosensor based on an Aerographite hybrid microtube, including a thin layer of CdTe. The results of this scientific paper have been published in one of the most prestigious scientific journals – “Nanotechnology” in England, with impact factor 3.4, DOI: 10.1088 / 1361-6528 / aaf0e7. Following an international competition, the results of the paper, along with the names of the authors, were selected for the front cover of the magazine “Nanotechnology”.
The authors of the paper demonstrate the importance of developing nanosensors based on individual micro- and nanostructures, which have a number of important advantages over conventional hybrid gas blends based on mixed hybrid powder from microparticles or films. Among the advantages mentioned above are highlighted: (I) reduced power consumption to nW values; (II) the possibility of operating at room temperature – eliminates the need to use microheaters; (III) ultra-high sensitivity due to improved surface-to-volume ratio – allows the integration of nanosensors onto flexible substrates in portable devices for use in applications such as bioelectronics, flexible electronics, intelligent clothing, environmental monitoring, and the “electronic nose”.
The importance of the development of this concept is the experimental confirmation of the possibility of hybridization of the lightest nanomaterial invented by humans, Aerographite, then the integration of an individual nanotube into nanosensors and its use for the rapid and ultra-sensitive detection of ammonia vapors. Ammonia is one of the main products of the chemical industry, nitrogenous chemical fertilizers, natural organic fertilizers, refrigeration systems, automotive industry and others. In the present, world-wide ammonia production reaches about 125 million tonnes, and most of the ammonia produced is used for nitrogen-based chemical fertilizers (about 88%). Thus, both for public and industrial security, there is a need for strict monitoring of the ammonia level in the air in order to avoid exposing people to lethal doses, but also for ecology, to study the effect of acidification of the environment.
The results of UTM researchers in collaboration with German scientists, the Teams of the teachers Adelung and Kienle, and the Academy of Sciences of Moldova, represent an important step in the field of hybrid nanomaterials, nanosensors and nanotechnologies at international level.
The paper is part of a comprehensive study of these aerographite-based materials as gas sensors. Aerographite is a carbon-based aerogel, one of the lightest materials (0.2 mg / cc), composed of 99.99% of air and interconnected carbon nanotubes and microtubes. From a historical point of view, the Aerographite was synthesized for the first time by the teams of researchers from the University of Hamburg and the University of Kiel, guided by prof. Rainer Adelung (DOI: 10.1002 / adma.201200491). The research of gas sensors, in collaboration with the Center for Nanotechnologies and Nanosensors of the Technical University of Moldova, the only one able to manufacture such nanosciences, has shown promising results for real-time gas monitoring for the environment both for personal safety and for public safety, but also for ecology. Due to the extremely low weight of the given material, ultra-light sensors can be manufactured to create portable atmospheric monitoring platforms at low or even extremely high heights.
These researches, reported and appreciated at international level, were partially supported by the institutional project inst-15.817.02.29A financed by the Government of the Republic of Moldova and TUM.