Lead zirconate titanate (PZT) ceramics is usually used as a piezoelectric material. However it has characteristics of not only piezoelectricity but also flexoelectricity. Piezoelectricity is a phenomenon that electric polarization is induced by strain, and flexoelectricity is the one that the polarization is induced by strain gradient. In this study, flexoelectricity in poled soft PZT ceramics ...

According to "Wolff's Law", bone is deposited and reinforced at areas of greatest stress. From a clinical perspective, this "law" is supported by the strong association between bone density and physical activity. From a mechanistic standpoint, however, the law presents a challenge to scientists seeking to understand how osteocytes and osteoblasts sense the mechanical load. In the 1960s, collage...

Piezoelectricity allows precise and robust conversion between electricity and mechanical force, and arises from the broken inversion symmetry in the atomic structure. Reducing the dimensionality of bulk materials has been suggested to enhance piezoelectricity. However, when the thickness of a material approaches a single molecular layer, the large surface energy can cause piezoelectric structur...

A thermodynamic model was constructed to analyze the negative capacitance effect in the presence of piezoelectricity. The model demonstrated that while piezoelectricity can lead to negative capacitance in principle, it is not strong enough in practice due to the unphysical amounts of charge and strain required. The inclusion of higher-order electromechanical coupling such as electrostriction ca...

The extracellular matrix of bone can be pictured as a material made of parallel interspersed domains of fibrous piezoelectric collagenous materials and non-piezoelectric non-collagenous materials. To mimic this feature for enhanced bone regeneration, a material made of two parallel interspersed domains, with higher and lower piezoelectricity, respectively, is constructed to form microscale piez...

ZnO has been extensively studied by virtue of its remarkably high piezoelectric responses, especially in nanowire forms. Currently, the high piezoelectricity of wurtzite ZnO is understood in terms of the covalent-bonding interaction between Zn 3d and O 2p orbitals. However, the Zn 3d orbitals are not capable of forming hybridized orbitals with the O 2pz orbitals since the Zn ion is characterize...

Intrinsic piezoelectricity and nontrivial band topology can coexist in monolayer InXO (X = Se Te), tensile strain enhance the piezoelectricity.

In this chapter, the indirect Trefftz collocation method is applied to solve the inverse Cauchy problem of linear piezoelectricity. The static analysis of coupled fields in 2D piezoelectric solids is considered. The piezoelectric material is modelled as a homogenous, linear elastic, linear dielectric and transversal isotropic. The T-functions are obtained by the Stroh formalism. The inverse Cau...

The highest symmetry in which piezoelectricity was thought to occur is cubic. Here it is shown that third rank piezoelectricity can occur in isotropic chiral solids. Polarization is coupled via an isotropic third rank tensor to the antisymmetric part of the stress. Asymmetric stress can occur if balanced by moments distributed over area or volume. Such moments occur in heterogeneous solids in w...

We extend our modeling of smart structures to second order piezoelectricity. We show that three different models have to be taken into account, which broadens the scope of the sensors and actuators field. Second order piezoelectricity being compatible with isotropy, we also propose a systematic study of the impact of crystalline symmetries on our models. To cite this article: T. Weller, C. Lich...