相关论文: Piezoelectric mimicry of flexoelectricity

Upon application of a uniform strain, internal sub-lattice shifts within the unit cell of a non-centrosymmetric dielectric crystal result in the appearance of a net dipole moment: a phenomenon well known as piezoelectricity. A macroscopic…

Metals exhibit a size-dependent hardening when subject to indentation. Mechanisms for this phenomenon have been intensely researched in recent times. Does such a size-effect also exist in the electromechanical behavior of…

Piezoelectricity is a technologically important property of certain insulators in which mechanical strain induces an electrical polarization. However, the rate at which a piezoelectric response can be established over a macroscopic volume…

A centrosymmetric stress cannot induce a polar response in centric materials, piezoelectricity is, for example, possible only in non-centrosymmetric structures. An exception is meta-materials with shape asymmetry, which may be polarized by…

Piezoelectrics are materials that linearly deform in response to an applied electric field. As a fundamental prerequisite, piezoelectric material must possess a non centrosymmetric crystal structure. For more than a century, this remains…

In this paper, a consistent theory is developed for size-dependent piezoelectricity in dielectric solids. This theory shows that electric polarization can be generated as the result of coupling to the mean curvature tensor, unlike previous…

Here the recently developed size-dependent piezoelectricity and the strain gradient theory of flexoelectricity are compared. In the course of this investigation, the strain gradient theory of flexoelectricity is shown to violate fundamental…

The propagation front of a crack generates large strain gradients and it is therefore a strong source of gradient-induced polarization (flexoelectricity). Herein, we demonstrate that, in piezoelectric materials, a consequence of…

Flexoelectricity is a universal effect that generates electric polarization due to broken inversion symmetry caused by local strain gradient. The large strain gradient at nanoscale makes flexo-electric effects, especially in nanoscopic…

The origin of frequently observed ultrahigh electric-induced longitudinal strain, ranging from 1% to 26%, remains an open question. Recent evidence suggests that this phenomenon is linked to the bending deformation of samples, but the…

The coupling between strain gradients and polarization, known as flexoelectricity, offers a new mechanism to control the functionality of dielectric materials. However, for the effect to be practically attractive, dynamic control of the…

We reveal that strong flexoelectric effect of solids can be induced due to the signfi?cant charge migration along the strain gradient direction, which represents a new understanding of the origin of flexoelectricity. Beyond the linear…

Modern electromechanical actuators and sensors rely on the piezoelectric effect that linearly couples strain and electric polarization. However, this effect is restricted to materials that lack inversion symmetry. In contrast, the…

Dielectric nano-swithes made of the materials that exhibit piezoelectric and/or flexoelectric properties with significant electro-mechanical coupling are considered. In this case, a nonuniform strain field may locally break inversion…

It has been well known that flexoelectricity can be exploited to generate an analogous piezoelectric response in non-piezoelectric materials. For the direct flexoelectric effect, the induced electric polarization is linearly proportional to…

Static flexoelectric effect in a finite sample of a solid is addressed in terms of phenomenological theory for the case of a thin plate subjected to bending. It has been shown that despite an explicit asymmetry inherent to the bulk…

Piezoelectrics with negative longitudinal piezoelectric coefficients will contract in the direction of an applied electric field. Such piezoelectrics are thought to be rare but there is no fundamental physics preventing the realization of…

Soft robotics requires materials that are capable of large deformation and amenable to actuation with external stimuli such as electric fields. Energy harvesting, biomedical devices, flexible electronics and sensors are some other…

Ferroelectric materials are characterized by the presence of an electric dipole that can be reversed by application of an external electric field, a feature that is exploited in ferroelectric memories. All ferroelectrics are piezoelectric,…

Flexoelectricity - polarization induced by strain gradients - offers a route to polar functionality in centrosymmetric dielectrics, where traditional piezoelectric effects are absent. This study investigates the flexoelectric effect in…