MAE Seminar: Plasma nanotechnology for multifunctional silver nanoparticles-based nanocomposites

Title: Plasma nanotechnology for multifunctional silver nanoparticles-based nanocomposites

Abstract: The current tendency of compact design of micro- and nano-devices requires integration of different functionalities in the same architecture. A way to respond to this demand is to apply materials with multifunctional properties to assemble the device. Typically, the multifunctional materials are under the form of piled very thin layers or nanostructures with specific patterns. They offer the possibility for transition from material level of development to system level of applications. For example, to provide a dielectric layer with enlarged and well-controlled electrical properties, one can use metallic inclusions (silver nanoparticles, AgNPs). The attractivity of AgNPs stems from their multifunctional properties, thus allowing to address different applications. This talk focuses on different functionalities of AgNPs produced by plasma processes. The nanostructures are based either on AgNPs embedded in thin silica layers or on AgNPs simply anchored on the surface of silica layers. Along with the different functionalities several applications of these nanocomposites are discussed. The optical properties of AgNPs are used to elaborate highly-performant plasmonic structures to address the protein adsorption problem, and particularly the conformational changes that proteins undergo when adhering of solid surfaces (silica) [1]. Charge injection and transport in dielectrics are demonstrated to be finely controlled via the AgNPs, thus providing solutions for electrical engineering (HVDC cables) and micro-/nano-electronic (MEMS RF switches and neuromorphic computing) applications [2-5]. The critical for space applications secondary electron emission from dielectrics under irradiation also is shown to be controlled by incorporating of AgNPs in the dielectric [6]. The catalytic properties of AgNPs appear extremely helpful to describe the role of metals in cosmic dust formation [7]. Last but not least, the AgNPs biocide properties are shown essential for fabrication of
tailored antimicrobial surfaces [8, 9]. The plasma processes prove versatile for the synthesis of very complex fine-scale structuring of the nanocomposites [10]. Combination of different AgNPs functionalities offers even larger scope of device fabrication.

Bio: Kremena MAKASHEVA is Director of Research at CNRS, Laboratory on Plasma and Conversion of Energy (LAPLACE), Toulouse, France. She obtained a PhD degree on Plasma Physics from Sofia University, Bulgaria, 2002, for her work on surface wave sustained plasmas. In 2003 she joined Université de Montréal, Canada for almost 4 years to work on surface wave plasmas at atmospheric pressure and particularly to study the contraction phenomenon of electrical gas discharges. In 2007 she moved to Toulouse, France to work in LAPLACE laboratory on modeling micro-discharges and microwave plasmas sustained by dipolar plasma sources. Since 2009 she works on plasma processes and plasma synthesis of nanostructured thin silica and organosilicon dielectric layers containing metallic nano-inclusions (silver nanoparticles – AgNPs and iron nanoparticles – FeNPs), their structural characterization and energetic analysis. Multifunctionality of AgNPs is in the heart of her research. In 2015 she and her colleagues proposed AgNPs-based blocking nanocomposite layers to control the transport of injected charges in dielectrics for HVDC-cable application. Her research activities are directed to the study of reactive plasmas, design and study of plasma synthesized nanostructured dielectrics containing AgNPs and FeNPs for biomedical, optical, micro-/nano-electronic, electrical engineering and space applications. She serves IEEE Nanotechnology Council (IEEE NTC) with different actions. Dr. Makasheva was IEEE NTC Vice-President for Technical Activities in 2020-2021, then she worked as IEEE NTC Vice-President for Conferences in 2022-2023. She is now President of the IEEE NTC, for the 2026-2027 term.