A Biaxial Strain Sensor Using a Single MoS2 Grating

In this paper, we report a new type of MoS2-based grating sensor for in-plane biaxial strain gauges with a precision limit of ~ 1‰. The MoS2 grating is numerically simulated with different biaxial strains up to 5%. Our first-principles calculations reveal that the strain sensitivity of the MoS2 reflectance spectrum can be considered an additional strain sensor integrated with the grating structure, enabling the mapping of in-plane biaxial strains. Our experimental studies on a prototype MoS2-grating sensor further confirm that a strain component perpendicular to the grating period can cause intensity peak shifts in the grating’s first-order diffraction patterns. This work opens a new path towards the sensing of in-plane biaxial strain within a single-grating device. Our new approach is applicable for other materials that have predictable reflectance response under biaxial strains and the capacity to form a two-dimensional single-crystal layer.

Hydrostatic piezoelectric parameters of lead-free 2–0–2 composites with two single-crystal components: Waterfall-like orientation dependences

A system of hydrostatic parameters is studied in novel 2–0–2 composites that contain two lead-free piezoelectric single-crystal components. The ferroelectric domain-engineered alkali niobate-tantalate-based single-crystal layer promotes large values of the piezoelectric coefficients [Formula: see text] and [Formula: see text], hydrostatic squared figure of merit [Formula: see text], and hydrostatic electromechanical coupling factor [Formula: see text] of the composite wherein the 0–3 Li2B4O7 single crystal/polyethylene layers are adjacent to the aforementioned single-crystal layer. Hereby, the role of the elastic anisotropy of the 0–3 layer is emphasized. An orientation effect concerned with rotations of the crystallographic axes of the piezoelectric Li2B4O7 single crystal in the 0–3 layer is first studied. It is shown that the orientation of the crystallographic axis [Formula: see text] of the Li2B4O7 single crystal in the polymer matrix strongly influences the piezoelectric properties and hydrostatic parameters of the composite. Examples of the so-called waterfall-like orientation dependences of the hydrostatic parameters are analyzed. The composite based on the domain-engineered [Lix([Formula: see text][Formula: see text]]([Formula: see text][Formula: see text]O3:Mn single crystal is of interest due to [Formula: see text][Formula: see text]mV[Formula: see text]m/N, [Formula: see text] Pa[Formula: see text], and [Formula: see text]–0.75 in the studied volume-fraction and orientation ranges, and these hydrostatic parameters are to be taken into account in the field of piezotechnical, hydroacoustic, and energy-harvesting applications.

Nonlinear anharmonic disturbances of elastic surface Love waves under rigid fixation of the waveguide

The model of geometrically and physically nonlinear deformation of anisotropic elastic medium is used in this work. A theoretical numerical-analytic solution of the boundary value problem of determining nonlinear anharmonic disturbances that are generated because of generalised Love wave propagation in a waveguide in the form of a single-crystal layer of the m3m class of a cubic system on the half-space of a single-crystal material of m3m class of a cubic system is constructed. The elastic layer on the top edge is rigidly fixed and on the bottom edge has ideal mechanical contact with the elastic halfspace. Numerical investigations have been carried out for a combination of waveguide materials: a layer of sodium chloride on the silicon half-space. Amplitude-frequency dependences for kinematic characteristics of elastic wave displacements of Love waves and their nonlinear second harmonics are researched and generalized.