  Kirigami-inspired designs can enable self-folding three-dimensional materials
from flat, two-dimensional sheets. Hierarchical designs of connected levels
increase the diversity of possible target structures, yet they can lead to
longer folding times in the presence of fluctuations. Here, we study the effect
of rotational coupling between levels on the self-folding of two-level kirigami
designs driven by thermal noise in a fluid. Naturally present due to
hydrodynamic resistance, we find that optimization of this coupling as control
parameter can significantly improve a structure's self-folding rate and yield.
