Instability mediated self-templating of drop crystals

The breakup of liquid threads into droplets is prevalent in engineering and natural settings. While drop formation in these systems has a long-standing history, existing studies typically consider axisymmetric systems. Conversely, the physics at play when multiple threads are involved and the interaction of a thread with a symmetry breaking boundary remain unexplored. Here, we show that the breakup of closely spaced liquid threads sequentially printed in an immiscible bath locks into crystal-like lattices of droplets. We rationalize the hydrodynamics at the origin of this previously unknown phenomenon. We leverage this knowledge to tune the lattice pattern via the control of injection flow rate and nozzle translation speed, thereby overcoming the limitations in structural versatility typically seen in existing fluid manipulations paradigms. We further demonstrate that these drop crystals have the ability to self-correct and propose a simple mechanism to describe the convergence toward a uniform pattern of drops.

Automated summary

The breakup of liquid threads into droplets is a common phenomenon in engineering and natural environments. Previous studies have mainly focused on axisymmetric systems, while the physics of multiple threads and the interaction between threads and symmetry-breaking boundaries have not been explored. This study discovered that closely spaced liquid threads printed in an immiscible bath form crystal-like lattices of droplets. By controlling the injection flow rate and nozzle translation speed, the lattice pattern can be adjusted, overcoming the limitations of structural versatility in existing fluid manipulation paradigms. Furthermore, it was found that these drop crystals have the ability to self-correct.