Ricerc@Sapienza

The problem of wave propagation control in one-dimensional systems, characterized by long-range interactions,
has been the main topic of several publications in recent years. The introduction of magnetostatic
or electrostatic forces modify the conventional connectivity based on the short-range interaction, classically
studied in structural mechanics. The present paper provides a new definition of long-range force, based on
the concept of small-world network. The small-world model, born in the field of social networks, is herein

Recently the authors proposed a model and related analysis on waves in long-range metamaterials. Nonlocal elasticity can be produced by several interacting forces acting between particles at long distance, as Coulomb or magnetic-static forces. The chance of introducing this long-distance forces has a disruptive effect in the elastic dynamics. In fact, classical elasticity is based only upon closest particles interaction in which short range-elastic forces act.

Nonlocal long -range effects are at the base of new phenomena investigated by the authors. In one dimensional systems, this permits the chance of modifying the phase and group velocity of the waveguide, even producing waves transporting energy backwards. In the two-dimensional case a richer scenario is opened. This paper investigates the chance of transporting the energy over a two-dimensional domain through vibrations that can follow a given path. The relationship between the path and the connection template is investigated.

Electromagnetic fields interacting with microscopic structural features in a composite material provide emerging optical properties that surpass those offered by the individual components. However, composite materials can be generally lossy due to the scattering effects induced by inhomogeneities at the interfaces between different compounds. To overcome such problems, complicated and costly manufacturing procedures, such as top-down approaches, are generally required.

In this review paper, some relevant models, algorithms, and approaches conceived to describe the bone tissue mechanics
and the remodeling process are showcased. Specifically, we briefly describe the hierarchical structure of the bone at
different levels and underline the geometrical substructure characterizing the bone itself. The mechanical models adopted
to describe the bone tissue at different levels of observation are introduced in their essential aspects. Furthermore, the

In this paper, a novel parameter determination technique is developed for mate-
rial models in continuum mechanics aimed at describing metamaterials. Owing
to their peculiar mechanical properties and behaviors, such as extreme elasticity
or high strength-to-weight ratio, metamaterials are of interest to be simulated by
reduced-order modeling by means of the generalized mechanics. Such models
incorporate constitutive parameters to be determined; we develop an automa-
tized optimization process specifically for obtaining metamaterials parameters.

Polar materials, i.e. those materials where it is possible to excite the collective oscillations of the lattice ions, along with derived phononic structures offer the possibility of manipulating and amplificating IR emissivity by the excitation of such surface modes. Since the oscillation frequencies of the crystalline lattice ions are typically lower, compared to the plasma frequencies, they fall in the infrared wavelength range.

In recent years, much effort has been expended upon managing and tuning the radiative properties of structures and material surfaces in the infrared (IR) wavelength range for several applications, such as thermal radiation control as well as IR sensing. Metamaterials are artificial electromagnetic materials, composed by periodically or randomly arranged, subwavelength elements.

Today, nanophotonics still lacks components for modulation that can be easily implementable in existing silicon-on-insulator (SOI) technology. Chalcogenide phase change materials (PCMs) are promising candidates for tuning in the near infrared: at the nanoscale, thin layers can provide enough contrast to control the optical response of a nanostructure. Moreover, all-dielectric metamaterials allow for resonant behavior without having ohmic losses in the telecom range. Here, a novel hybridization of a SOI-based metamaterial with PCM GeTe is experimentally investigated.