Microtubular Teardrop Patterning and the Growing Process

ABSTRACTHere we show that microtubular bundles bend flexibly under a hydrodynamic flow to form teardrop patterns. In a highly concentrated microtubular solution, patterns of same-sized teardrops form according to the maximum critical curvature, which is determined by the specific rigidity of the microtubules. Our understanding is that these micropatterns grow when microtubular bundles with hydrodynamic flow energy are converted into stable teardrop patterns as a higher structure. This conversion is generated by the combined effect of multiple kinds of energy, including heat and hydrodynamic flow, as well as life systems. These self-generating patterns in a spatio-temporal stream are reminiscent of what the artist Edward Munch calleda scream of nature. We also envision that microtubular pattering with hierarchical structure will broaden the potential application of these geometrical structures and guide biomimetic material engineering towards areas such as integrated energy conversion, soft material patterning, and living signal transduction.