Position control of desiccation cracks by memory effect and Faraday waves

Abstract

Pattern formation of desiccation cracks on a layer of a calcium carbonate paste is studied experimentally. This paste is known to exhibit a memory effect, which means that a short-time application of horizontal vibration to the fresh paste predetermines the direction of the cracks that are formed after the paste is dried. While the position of the cracks (as opposed to their direction) is still stochastic in the case of horizontal vibration, the present work reports that their positioning is also controllable, at least to some extent, by applying vertical vibration to the paste and imprinting the pattern of Faraday waves, thus breaking the translational symmetry of the system. The experiments show that the cracks tend to appear in the node zones of the Faraday waves: in the case of stripe-patterned Faraday waves, the cracks are formed twice more frequently in the node zones than in the anti-node zones, presumably due to the localized horizontal motion. As a result of this preference of the cracks to the node zones, the memory of the square lattice pattern of Faraday waves makes the cracks run in the oblique direction differing by 45 degrees from the intuitive lattice direction of the Faraday waves.

Membrane remodeling and mechanics: Experiments and simulations of α-Synuclein

“…In neither case have there been systematic studies of the effect of adsorbed proteins on the material properties. A recent study evaluated bending rigidity constants from vesicles extruded with ~40–50 nm radii, however dynamic light scattering (DLS) experiments indicated that some of the radii quickly grew to 70–80 nm [62], rendering these vesicles substantially larger than an average synaptic vesicle (~40 nm) [172]. NSE measurements were fit based on the Helfrich-like treatment of a bilayer as a thin, homogenous sheet by Zilman and Granek [61] and bending rigidities were determined via the undulation relaxation rates.…”

Morphometric analysis of polygonal cracking patterns in desiccated starch slurries

“…Earlier studies have elucidated the mechanism of desiccation crack formation for various grain-liquid mixtures [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] . The mixtures typically consist of a skeleton of solid grains and pore spaces that are filled with either liquid or air bubbles.…”

Effect of disorder on shrinkage-induced fragmentation of a thin brittle layer

“…7 the fraction of broken beams is practically the cumulative probability of breaking P b (ε), which in principal could be obtained analytically from the density functions Eq. (10). Neglecting the role of bending in breaking, a linear function is obtained P b (ε) = (1/2W ε )(ε − ε th + W ε ) for ε ε th − W ε .…”

“…Detailed experiments varying the way of excitation, furthermore, the strength and range of interaction of colloidal particles have * ferenc.kun@science.unideb.hu revealed that the memory effect of pastes provides an efficient way of controlled generation of crack patterns in thin layers. For example, by applying vertical vibration to the thin layer of paste, the position of crack formation can be controlled, because Faraday waves localize stronger horizontal vibration at node regions where cracks appear earlier than in other regions [10]. Effectiveness of memory of paste can be controlled by adding sodium chloride to paste, because the strength and range of interaction between charged colloidal particles in paste can be controlled by the screening effect [11].…”

“…In colloidal suspensions the amount of disorder can be controlled, e.g., by varying the range and the functional form of the size distribution of colloid particles. Vibration and flow of pastes gives rise to well-ordered crack structures since the initial mechanical excitation imprints a directional or spatial distribution of density fluctuations and plastic deformation, which overcomes the effect of disorder in the local fracture strength for crack formation [10,12]. Hence, it is an interesting question how the competition of the structural heterogeneity and the disorder of the local fracture strength of the material determines the evolution of shrinkage-induced cracking and the size distribution of fragments.…”