Computational evaluation of the flexoelectric effect in dielectric solids

By A. Abdollahi, C. Peco, Daniel Millán, Marino Arroyo, Irene Arias. Journal of Applied Physics, 2014

225 citations recorded by the source corpus.

Flexoelectricity is a size-dependent electromechanical mechanism coupling polarization and strain gradient. It exists in a wide variety of materials, and is most noticeable for nanoscale objects, where strain gradients are higher. Simulations are important to understand flexoelectricity because experiments at very small scales are difficult, and analytical solutions are scarce. Here, we computationally evaluate the role of flexoelectricity in the electromechanical response of linear dielectric solids in two-dimensions. We deal with the higher-order coupled partial differential equations using smooth meshfree basis functions in a Galerkin method, which allows us to consider general geometries and boundary conditions. We focus on the most common setups to quantify the flexoelectric response, namely, bending of cantilever beams and compression of truncated pyramids, which are generally interpreted through approximate solutions. While these approximations capture the size-dependent flexoelectric electromechanical coupling, we show that they only provide order-of-magnitude estimates as compared with a solution fully accounting for the multidimensional nature of the problem. We discuss the flexoelectric mechanism behind the enhanced size-dependent elasticity in beam configurations. We show that this mechanism is also responsible for the actuation of beams under purely electrical loading, supporting the idea that a mechanical flexoelectric sensor also behaves as an actuator. The predicted actuation-induced curvature is in a good agreement with experimental results. The truncated pyramid configuration highlights the critical role of geometry and boundary conditions on the effective electromechanical response. Our results suggest that computer simulations can help understanding and quantifying the physical properties of flexoelectric devices.

Subfields: Control and Systems Engineering, Materials Chemistry, Mechanics of Materials

View Paper: https://www.semanticscholar.org/paper/2bd021f91661db2c2e23f6c07e80f3ecaee8a8a3

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Citations in the corpus

A multi-material level set-based topology optimization of flexoelectric composites (2018, unknown): “Table 2 Properties of Active 1 (BaT i O3 [16]), Active 2, Active 3, passive and void phases.”
A level-set based IGA formulation for topology optimization of flexoelectric materials (2017, methodology): “Our results, which are converged on a sufficiently fine discretization, are in good agreement with the benchmark example [12] from both values and field distribution points of view.”