Physics of Living Tangled Matter

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

Knotted and tangled filamentous structures are hallmarks of living systems and human technologies, from DNA to weaving. By contrast, design principles for tangled active matter that can autonomously self-assemble, disassemble, and break symmetry are currently unknown. The Principal Investigator (PI) proposes to explore this new frontier of materials science and applied mathematics by studying the physics of living knots and tangles. This research is made possible by the PI's discovery of blackworms (Lumbriculus variegatus) that intertwine with each other in complex, topological patterns to form soft blobs. These blobs can aggregate, shape-shift, engulf, transport cargo, and dissolve rapidly. The blobs represent a unique example of a knotted living material that uses topological mechanics to produce emergent, intelligent behavior, not seen in other known materials. Motivated by the fascinating behavior of these worms, in this award the PI will use mathematical theory to construct minimal tangling and untangling states that enable control over the topological structure. The PI will develop experimental techniques and low-dimensional representation to characterize the worm blob as a topologically tunable material. The PI will also develop multi-physics models of tangling worms as active filaments, linking physical properties of tangled fibers, such as energy and elastic torque, to topological parameters such as link, writhe, and crossing number. Finally, the PI will develop control schemes and unifying phase diagrams for predictive shape-morphing and symmetry-breaking in tangled ensembles. With this award, the PI's interdisciplinary research on the physics of living tangles and knots has the potential to impact a wide range of fields, including mathematics, materials science, biology, and physics. Beyond advancing our understanding of living systems, this work could also lead to breakthroughs in the development of stimuli-responsive materials, living fabrics, and shape-morphing robots that could navigate challenging environments like the deep ocean or Mars. The PI also plans to involve, mentor, and educate young scientists at all levels, from K-12 to postdocs. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.