Search Results (2)

The paper describes the simulation of energy absorption in polymer micro-composites that include dielectric inserts (commercial Al₂O₃ and TiO₂ particles, with three particle sizes of 1, 5 and 25 µm, respectively). The investigated frequency spectrum, mainly from 0.001 to 100 GHz, is designed for various uses as substrates in electronic technologies. The electromagnetic simulation software chosen was CST Studio Suite, which evaluates the power loss at different frequencies, playing a crucial role in creating the ideal structure of these substrates. The effective limits of the electromagnetic simulation are specified. It is shown that a considerable increase in absorption occurs, by a factor of 12 to 120, depending on the dielectric material used for the inserts and the mass ratio applied in the insertion technique. Dielectrics with high permittivity provide higher absorption, but also create a nonuniform field distribution within the material, resulting in a high peak-to-average absorption ratio. In scenarios where this behavior is intolerable, the technology must be carefully tuned to improve the consistency of the insertions in the substrate material. The final outcomes of the simulations indicated that for creating new substrates for flexible electronics, polyethylene composites with TiO₂ insertions are suggested, particularly at lower concentrations of up to 7% and with a larger radius, such as 25 μm, which could offer significant economic advantages considering that the current concept advises the use of costly particles ranging from nanoscale particles to those 1 μm in size and a composition exceeding 10%. Full article

This paper describes the simulation of the S (scattering)-parameters and absorbed energy for polymeric nanocomposites with metallic insertions (iron and aluminum, with two particle dimensions). The considered frequency domain, 0.1–3 GHz, is specific for a wide range of applications in microwave technologies. The actual limitations of electromagnetic simulations are described, along with an application related to the Nicolson–Ross–Weir procedure in infinite media, which opens new perspectives in nanocomposite electromagnetic modeling. It was demonstrated that, due to a higher conductivity, nanocomposites with Al particles can absorb a larger amount of energy compared to Fe particles within composite materials, at both insertion dimensions. At higher frequencies, the power loss density increases for both metals. The significant reduction in transmission, linked to a minimal reflection, verifies that for composites with added metallic powder, microwave energy is extensively absorbed by the materials, particularly at frequencies above 1.5 GHz, confirming their potential functionality as hot melts for advanced reversible bonding technologies. Full article