Several modern cutting edge technologies, including the superconducting technology, green energy generation/storage technology, and the emerging 5G networks technology, have some form of thin-film coatings. Hence, this critical review showcased the historical evolution, conventional deposition technologies with its application areas, growth modes, specific thin-film stress-state micro/nano-level measurement and models, and prospects projection of thin-film coatings. Specifically, the authors included simple schematics of the primary thin-film coating methods (chemical vapor deposition and physical vapor deposition methods), growth modes, residual stress evolution behavior from valuable up to date models to enhance in-depth understanding of the underlying principles of thin-film coatings techniques and challenges. Also, the authors pointed out specific deficiencies in the reported thin-film stress measurement/models approaches. It is scientifically shown that no coating technique or model has superior results in all scenarios, selecting a suitable coating technique or model depends on the targeted materials and functions of the thin-film system. According to the evaluated reports, the societal demand and specific challenge in the fabrication/applications of thin-film systems indicated that thin-film coatings and its associated challenges would remain vibrant and active research areas for periods far into the future. Thus, this report would serve as a guide and reference material for potential researchers in these areas for a considerable time.

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Magnetorheological (MR) materials are classified as smart materials that can alter their rheological features once exposed to peripheral magnetic fields. MR materials have been a standard and one of the primary smart materials for the last few decades due to their outstanding vibration control performance in adaptive sandwich structures and systems. This paper reviews the vibration suppression investigations of flexible constructions using MR elastomers (MREs). In relations of field-dependent controllability, physical features such as stiffness and the damping of different geometrical structures integrated with the core layer of MREs are explored. The veracity of the knowledge is discussed in this article, whereby sandwich structures with different MR treatment configurations are analyzed for free and forced vibration, MRE sandwich structures are analyzed for stability under different working conditions, and the optimal positions of fully and partially treated MRE sandwich structures for improved vibration control are identified. MR materials′ field-dependent stiffness and damping characteristics are also discussed in this article. A few of the most noteworthy research articles over the last several years have been summarized.

In this article a sandwich beam structure with honeycomb core filled of MRE (magnetorheological elastomer) with different ratios of Elastomer and iron particles is proposed. Modal response for structures with Nylon and Resin8000 honeycomb core filled with MRE and sandwiched between aluminum face sheets were analyzed and compared for two different ratios of MRE by placing magnets at free end and center of the structure. The force generated by magnets on the sandwich beam structure was calculated using ANSYS EDT and the modal response of the structure was then observed under generated magnetic force using ANSYS Workbench. The results showed that the resonance frequency of the structure decreased as the magnetic intensity was increased for all the cases specially for the first mode. Secondly structure with Nylon honeycomb core showed lower frequency drop and higher deformation than the structure with Resin8000 honeycomb core.