Synergistic effect of surface-flexoelectricity on electromechanical response of BN-based nanobeam

This article is divided into two main sections. The focus of the first is the determination of the effective piezoelectric and dielectric properties of Boron-Nitride (BN) reinforced nanocomposite (BNRC) and the focus of the second is the electromechanical response of the BNRC beam accounting for surface and flexoelectric effects. The effective properties of the BNRC were obtained using micromechanics and homogenization techniques that consider Hill’s average concentration factor, while in the second the electromechanical response, which requires the developed effective BNRC properties, was analytically determined by making use of size-dependent Euler–Bernoulli (E–B) beam description and an extended theory of linear piezoelectricity. The considered beam is subjected to a uniformly distributed load with three different types of support: clamped–clamped, simply-supported, and clamped-free. The outcomes of E–B beam model are also compared with that of FE results and are found to be in excellent agreement. Our results reveal that the electromechanical properties of BNRC are improved in the transverse direction, which in turn activates transverse actuation under the applied field. Furthermore, our results show that the size-dependent flexoelectric and surface effects must be considered for the accurate modeling of active nanostructures. We also observed that the bulk flexoelectric effect stiffens the nanobeam irrespective of the support type, whereas the surface effect stiffens or softens the nanobeam depending on the support type. This foundational study highlights the scope for the development of high-performance and efficient BN-based piezoelectric nanostructures, which can be used in nanoelectromechanical systems and structural health monitoring applications.