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of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

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Author: Robert Andok

  • DOMINANT TECHNOLOGIES IN “INDUSTRY 4.0”

    2D graphene layers in chemiresistive sensors

    • Evgeniy Manoilov
    • Ivan Kostic
    • Katia Vutova
    • Robert Andok
    Industry 4.0, Vol. 10 (2025), Issue 2, pg(s) 53-55
    • Abstract
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    In this paper, a two-dimensional (2D) material graphene with exceptional electronic and mechanical properties is discussed as a promising candidate for chemiresistive sensor applications. High surface area and superior charge carrier mobility of graphene enable rapid and sensitive detection of gaseous analytes, making it an attractive alternative to conventional metal oxide semiconductor (MOS) sensors. The review of recent advancements in graphene-based chemiresistive gas sensors is done, highlighting their operational principles, fabrication techniques, and performance enhancements through material modifications such as reduced graphene oxide (rGO). Additionally, we examine the application of graphene sensors in environmental monitoring, where their ability to detect pollutants like NO₂ , NH₃ , and CO₂ with high sensitivity and low power consumption provides a significant advantage over traditional sensing technologies. Despite these advancements, challenges such as selectivity, standardization, and sensor stability remain critical areas for future research.

  • DOMINANT TECHNOLOGIES IN “INDUSTRY 4.0”

    Two-dimensional WS2 layer in sensor application

    • Robert Andok
    • Katia Vutova
    • Ivan Kostic
    • Evgeniy Manoilov
    Industry 4.0, Vol. 10 (2025), Issue 1, pg(s) 25-26
    • Abstract
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    This paper presents a study on the current state of research and use of dichalcogenides of transition metals, particularly WS2. The properties of WS2 in the context of its application in sensor technology and highlight the anticipated advantages of nanostructured disulfides are discussed.

  • DOMINANT TECHNOLOGIES IN “INDUSTRY 4.0”

    2D semiconductive nanomaterials for sensor application

    • Pavol Nemec
    • Katia Vutova
    • Anna Bencurova
    • Robert Andok
    • Ivan Kostic
    Industry 4.0, Vol. 9 (2024), Issue 1, pg(s) 6-9
    • Abstract
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    This paper presents an investigation of innovative nanostructured semiconductive materials, focusing on dichalcogenides of transition metals, particularly WS2. The properties of WS2 in the context of its application in sensor technology and highlight the anticipated advantages of nanostructured disulfides compared to bulk semiconductor materials are discussed in the introduction. We propose a model sensor element based on the nanostructured disulfide WS2 and introduce a technological method utilizing electron beam lithography (EBL) for its preparation. The paper details the processes involved in preparing the resist masking layer using EBL, the metallization of the interdigital electrode (IDE) with contacts and important EBL characteristics such as a contrast curve, dependence of the linewidth on the exposure dose, and the line edge roughness.

  • TECHNOLOGICAL BASIS OF “INDUSTRY 4.0”

    EBL in the Industry 4.0 Era

    • Ivan Kostic
    • Katia Vutova
    • Elena Koleva
    • Anna Bencurova
    • Robert Andok
    Industry 4.0, Vol. 8 (2023), Issue 8, pg(s) 381-384
    • Abstract
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    In this work, electron beam lithography (EBL) is presented as an important technology shaping the future of semiconductor manufacturing within the Industry 4.0 initiative. The EBL contribution to the ongoing evolution of electronic devices and technologies is discussed in the context of the Industry 4.0 initiative. Semiconductor technologies are foundational to the implementation of Industry 4.0, playing a critical role in enabling advanced computing, communication, sensing, and control systems. They facilitate the creation of intelligent, interconnected, and automated systems in the Industry 4.0 initiative. In addition, we present some of our results in the field of EBL research. The focus is on investigating the electron beam resist profile depending on various process parameters. The influence of electron beam lithography parameters, such as electron energy, resist thickness, and exposure dose, on the resist sidewall shape (profile) is studied for the PMMA (polymethyl-methacrylate) positive electron beam resist. Simulation results based on measurements along the resist profile depth are presented and discussed. The aim of this work is to develop and validate models for predicting and precisely controlling resist profiles in thick PMMA layers applied in the fabrication of electronic devices.

  • DOMINANT TECHNOLOGIES IN “INDUSTRY 4.0”

    Optimization of electron beam lithography processing of resist AR-N 7520

    • Elena Koleva
    • Ivan Kostic
    • Lilyana Koleva
    • Katia Vutova
    • Irina Markova
    • Anna Bencurova
    • Anna Konecnikova
    • Robert Andok
    Industry 4.0, Vol. 6 (2021), Issue 5, pg(s) 189-191
    • Abstract
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    This work presents experimental and theoretical investigation of exposed and developed negative electron resist AR-N 7520 profiles using electron beam lithography system ZBA23 (Raith) at variation of the exposure doses and pre-defined exposure pattern. Several overall geometry quality criteria for the shape of the developed resist profile cross-sections are defined. Empirical models are estimated for the dependence of overall geometry characteristics of the obtained resist profiles on the exposure dose. These overall quality characteristics are used for defining of technological requirements for the formed profiles and for obtaining optimal regimes by multicriterial optimization.

Congresses and conferences

  • IX International Scientific Conference
    "High Technologies. Business. Society"
    04.-07.03.2024 - Borovets, Bulgaria
  • XXI International Congress
    "Machinеs. Technolоgies. Materials."
    Winter session
    06.-09.03.2024 - Borovets, Bulgaria
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    17.-19.04.2024 - Pleven, Bulgaria
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    26.-29.06.2024 - Varna, Bulgaria
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    09.-12.12.2024 - Borovets, Bulgaria
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  • IX International Scientific Conference
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    Winter session
    11.-14.12.2024 - Borovets, Bulgaria
  • VI International Scientific Conference
    "Mathematical Modeling"
    11.-14.12.2024 - Borovets, Bulgaria

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