Adaptive nonequilibrium design of actin-based metamaterials: Fundamental and practical limits of control

Journal Article · 14 February 2024 · Proceedings of the National Academy of Sciences of the United States of America

DOI: https://doi.org/10.1073/pnas.2310238121 · OSTI ID:2305554

Chennakesavalu, Shriram  ^[1]; Manikandan, Sreekanth K. ^[1]; Hu, Frank ^[1]; Rotskoff, Grant M.  ^[2]

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1. Department of Chemistry, Stanford University, Stanford, CA 94305
2. Department of Chemistry, Stanford University, Stanford, CA 94305, Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA 94305

The adaptive and surprising emergent properties of biological materials self-assembled in far-from-equilibrium environments serve as an inspiration for efforts to design nanomaterials. In particular, controlling the conditions of self-assembly can modulate material properties, but there is no systematic understanding of either how to parameterize external control or how controllable a given material can be. Here, we demonstrate that branched actin networks can be encoded with metamaterial properties by dynamically controlling the applied force under which they grow and that the protocols can be selected using multi-task reinforcement learning. These actin networks have tunable responses over a large dynamic range depending on the chosen external protocol, providing a pathway to encoding “memory” within these structures. Interestingly, we obtain a bound that relates the dissipation rate and the rate of “encoding” that gives insight into the constraints on control—both physical and information theoretical. Taken together, these results emphasize the utility and necessity of nonequilibrium control for designing self-assembled nanostructures.

• Sponsoring Organization: USDOE
• Grant/Contract Number: SC0022917
• OSTI ID: 2305554
• Alternate ID(s): OSTI ID: 2472118
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 8 Vol. 121; ISSN 0027-8424
• Publisher: Proceedings of the National Academy of SciencesCopyright Statement
• Country of Publication: United States
• Language: English