Nanostructured surfaces

The effect of surface inhomogeneity on coupled fields in thermoelastic polarized small scale structures 
Hrytsyna O. R.
Department of mechanics, Institute of Construction 
and Architecture, Slovak Academy of Sciences, 
Dúbravská cesta 9, Bratislava 45, 84503, Slovakia 
Department for mathematical methods of computing experiment, 
Center of Mathematical Modeling of Pidstryhach Institute for Applied 
Problems of Mechanics and Mathematics, NAS of Ukraine, 
Dudajev str., 15, Lviv, 79005, Ukraine; 
E-mail: hrytsyna.olha@gmail.com

It is known that size effects become significant when specimen dimensions are reduced to the micro-/nano-meter scale. In this study with the aim to describe the behavior of elastic small-scale structures the local gradient theory of dielectrics is used. The fundamentals of this theory were developed in a series of papers and were recently generalized in the book [1]. This gradient-type theory is based on the consideration of coupling between the processes of mechanical deformations, thermal conductivity, polarization and the local mass displacements. Within this theory, the local mass displacement is linked to the microstructure changes of the material including atomic reordering at the surface/interface regions. In this work, the local gradient theory is applied to a series of one-dimensional problems related to isotropic dielectrics. Relations of the mentioned theory are used to study the surface effects in piezoelectric nanosize plates and fibers with free and clamped surfaces. It is shown that by taking the local mass displacements into consideration interaction between thermal, electric, and mechanical fields can be studied in elastic continua including isotropic centrosymmetric materials with cubic symmetry. 
Obtained results could be significant for the design of new nanocomposite materials and small-scale devices as they provide new criteria for the prediction of size effects and electro-thermo-mechanical coupling in materials with high symmetry of the lattice.
Acknowledgement. The author acknowledges support from the Slovak Science and Technology Assistance Agency registered under number SK-CN-RD-18-0005. 
1.	Hrytsyna O., Kondrat V. Local Gradient Theory for Dielectrics: Fundamentals and Applications. 2020, Jenny Stanford Publishing Pte Ltd, Singapore.