Erasure of memory in paste by irradiation of ultrasonic waves

Akio Nakahara, Ryota Yoneyama, Maruto Ito, Yousuke Matsuo, So Kitsunezaki, F. Radjai, S. Nezamabadi, S. Luding, J.Y. Delenne
2017 EPJ Web of Conferences  
Densely packed colloidal suspension, called paste, remembers the direction of applied forces, such as vibration and flow, and these memories kept in paste can be visualized as morphology of desiccation crack patterns. For example, when the paste remembers the direction of vibration, all primary cracks propagate in the direction perpendicular to the direction of initial vibration. On the other hand, when the paste remembers the direction of flow, all primary cracks propagate along the direction
more » ... long the direction of initial flow. These results indicate that external forces imprint easy-breakable direction into paste as memories. Therefore, by controlling memories in paste, we can tune to produce various types of crack patterns, such as cellular, radial, lamellar, ring, spiral and lattice structures. Recently we have found that memories in paste can be erased by the irradiation of ultrasonic waves to paste as we obtain only isotropic and cellular crack patterns without any anisotropy related to memory effect. This method can be applied to increase the breaking strength of dried paste by homogenizing microstructure in paste.
doi:10.1051/epjconf/201714012007 fatcat:etpj7l7shvcmjef4ra2wsal6d4