Scaling effect of flexoelectric (Ba,Sr)TiO₃microcantilevers

Abstract

The flexoelectric microcantilever offers an alternative approach for the development of micro/nano‐sensors. The transverse flexoelectric coefficients µ12 of barium strontium titanate microcantilevers were measured at room temperature, and found to keep the same value of 8.5 µC/m for microcantilevers with thickness ranging from 30 µm to 1.4 mm. The calculated effective piezoelectric coefficient and electrical energy density of flexoelectric cantilevers are superior to those of their piezoelectric counterparts, suggesting that the flexoelectricity‐induced polarization can be significantly increased as structures are scaled down due to the scaling effect of strain gradient, holding promise for flexoelectric micro/nano cantilever sensing applications. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Fundamentals of flexoelectricity in solids

“…Resta's framework employs the response function of the local microscopic electric field to an atomic displacement, calculated at fixed macroscopic field, instead of the response function of microscopic charge density (32). Since the field and the charge density are linked via the Poisson equation, Resta's framework is equivalent to that developed above [48].…”

Grain size effect on electrical resistivity of bulk nanograined Bi2Te3 material

“…Solid-state materials are known to demonstrate considerable sizedependent physical phenomena [1][2][3][4]. Nanomaterials including nanowires, thin films, nanoparticles, nanocomposites, and nanograined materials are suitable and informative objects to research finite-size effects on various physical properties of solids [5].…”

Relationship between direct and converse flexoelectric coefficients

“…24 Moreover, the micro/nano scale flexoelectric effect was proved to be extremely significant and hence broadened the application of flexoelectricity into thin films. [25][26][27][28] Intriguingly, some special designed heterogeneous thin films exhibited attractive physical phenomena in the aspects of strain gradient induced hysteresis loop shift and mechanical force induced polarization reversal, in response to the scaling effect of flexoelectricity. [29][30][31][32][33][34] In crystalline medium, the strain gradient will result in the polarization, while on the other hand, the electric field gradient will result in mechanical strain, as schematically shown in Figs …”