Laser-Driven Accelerated Growth of Dendritic Patterns in Liquids

We report a scheme for very significantly accelerated growth of dendritic patterns in organic, inorganic, polymeric, and biological liquids, using laser power as low as a few hundred microwatts in the presence of an efficient absorber such as carbon nanotubes (CNTs). The CNTs act as a heat source that drives dendritic growth; their anisotropy ensures a rich diversity of branched patterns. We have studied the time evolution of the accelerated growth patterns; growth patterns are seen on millisecond time scales. We rationalize such unprecedented speed of dendritic growth using a diffusion equation for the temperature field with an additional source term. The predictions of the well-established microscopic solvability theory (MST) are seen to hold on time scales in excess of 100 ms even with the introduction of an additional source term to account for our laser beam. On the other hand, on time scales shorter than 100 ms, MST is seen to break down. Our method opens new vistas for studies on the dynamics of dendritic patterns and crystal growth.