2014 The theoretical description of the threshold and near-threshold behavior of electrohydrodynamic convection in nematic liquid crystals in the (low-frequency) conduction regime is reconsidered. We present essentially the full three-dimensional linear stability analysis of the basic state and a major part of the weaklynonlinear theory of the convective state. Boundary conditions at the upper ...

We investigated the dependence of electromechanical coupling and the piezoelectric response of a micromachined Pb(Zr₀.₅₂Ti₀.₄₈)O₃ (PZT) diaphragm on its curvature by observing the impedance spectrum and central deflection responses to a small AC voltage. The curvature of the diaphragm was controlled by applying air pressure to its back. We found that a depolarized flat diaphragm does not initia...

Flexoelectric hydrophones offer the possibility of reasonable sensitivity in lead-free systems. In this work, a dense barium strontium titanate ceramic with Ba:Sr ratio 70:30 and an effective flexoelectric coefficient, μ ~12, 105.6 ± 0.6 μC/m at room temperature was utilized prototype three-point bending hydrophone dimensions 77 × 10 0.67 mm3. Tap testing calibrated acoustic hammer showed reson...

An unexpected type of behavior in electroconvection (EC) has been detected in nematic liquid crystals (NLCs) under the condition of comparable time scales of the director relaxation and the period of the driving ac voltage. The studied NLCs exhibit standard EC (s-EC) at the onset of the instability, except one compound in which nonstandard EC (ns-EC) has been detected. In the relevant frequency...

We first revisit the mathematical modeling of flexoelectric effect in context continuum mechanics at infinitesimal deformations. establish and clarify relation between different formulations, point out theoretical numerical issues related to resulting boundary value problems, present natural extension finite then a simple B-spline based computational technique numerically solve associated which...

We consider a mathematical model that consists of a nematic liquid crystal layer sandwiched between two parallel bounding plates, across which an external field is applied. We investigate how the number and type of solutions for the director orientation within the layer change as the field strength, anchoring conditions, and material properties of the nematic liquid crystal layer vary. In parti...