Position control of desiccation cracks by memory effect and Faraday waves.

Area of Science:

• Materials Science
• Soft Matter Physics
• Pattern Formation

Background:

• Desiccation cracks in calcium carbonate paste exhibit a memory effect, where horizontal vibrations predetermine crack direction.
• Crack positioning typically remains stochastic even with directional memory.
• Controlling crack patterns is crucial for understanding material behavior and applications.

Purpose of the Study:

• To investigate the control of desiccation crack positioning in calcium carbonate paste.
• To explore the influence of vertical vibration and Faraday wave patterns on crack formation.
• To break the translational symmetry of crack patterns.

Main Methods:

• Experimental study of pattern formation in calcium carbonate paste.
• Application of short-time horizontal and vertical vibrations to fresh paste.
• Imprinting Faraday wave patterns using vertical vibrations.
• Analysis of crack formation in relation to Faraday wave node and anti-node zones.

Main Results:

• Vertical vibration and Faraday waves enable control over crack positioning, not just direction.
• Cracks preferentially form in the node zones of Faraday waves (e.g., twice as frequent in stripe patterns).
• The square lattice pattern of Faraday waves influences crack orientation, leading to oblique directions.

Conclusions:

• Vertical vibration offers a method to control desiccation crack positioning by imprinting Faraday wave patterns.
• The observed crack preference for node zones suggests localized horizontal motion is a key factor.
• This research expands the understanding of memory effects and pattern control in drying materials.