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Statistical reprogramming of macroscopic self-assembly with dynamic boundaries




Self-assembly is a ubiquitous process that can generate complex and functional structures via local interactions among a large set of simpler components. The ability to program the self-assembly pathway of component sets elucidates fundamental physics and enables alternative competitive fabrication technologies. Reprogrammability offers further opportunities for tuning structural and material properties but requires reversible selection from multistable self-assembling patterns, which remains a challenge. Here, we show statistical reprogramming of two-dimensional (2D), noncompact self-assembled structures by the dynamic confinement of orbitally shaken and magnetically repulsive millimeter-scale particles. Under a constant shaking regime, we control the rate of radius change of an assembly arena via moving hard boundaries and select among a finite set of self-assembled patterns repeatably and reversibly. By temporarily trapping particles in topologically identified stable states, we also demonstrate 2D reprogrammable stiffness and three-dimensional (3D) magnetic clutching of the self-assembled structures. Our reprogrammable system has prospective implications for the design of granular materials in a multitude of physical scales where out-of-equilibrium self-assembly can be realized with different numbers or types of particles. Our dynamic boundary regulation may also enable robust bottom-up control strategies for novel robotic assembly applications by designing more complex spatiotemporal interactions using mobile robots.

Author(s): Culha, Utku and Davidson, Zoey S and Mastrangeli, Massimo and Sitti, Metin
Journal: Proceedings of the National Academy of Sciences
Volume: 117
Number (issue): 21
Pages: 11306-11313
Year: 2020

Department(s): Physical Intelligence
Bibtex Type: Article (article)
Paper Type: Journal

DOI: 10.1073/pnas.2001272117
State: Published


  title = {Statistical reprogramming of macroscopic self-assembly with dynamic boundaries},
  author = {Culha, Utku and Davidson, Zoey S and Mastrangeli, Massimo and Sitti, Metin},
  journal = {Proceedings of the National Academy of Sciences},
  volume = {117},
  number = {21},
  pages = {11306-11313},
  year = {2020}