Fig. 5: Self-assembly of Robo-Matter.

a Ultra-fast hierarchical self-assembly. Left panels show the snapshots of the assembly process of 500 Magbots with 0.66 N magnets in a homogeneous light field with an intensity I_L = 200 a.u., where the green lines highlight the bonds between Magbots (Supplementary Movie 2). The right panel shows the dynamic function \(S(t)=-{{{\rm{\ln }}}}[1-x(t)]\) in logarithmic scales for varying magnetic binding strength, where x(t) is the fraction of Magbots in a largest assembled cluster at time t. The Avrami index α associated with S(t) ~ t^α increases with increasing magnetic binding strength and achieves the maximum α ≈3.3 for the strongest magnets (0.66 N). The error bars represent the standard deviations, and the experiments have been performed for six times for each magnetic binding strength. b Structural self-correction (left panels) in which a disordered local region (indicated by the yellow dotted circle) broke down and reassembled into a honeycomb structure (Supplementary Movie 2). The corresponding evolution of the local topological order parameter h₆ is shown in the right panel. The red and green lines in the snapshots shown in (b) respectively highlight the bonds in locally ordered and disordered regions. The horizontal dotted lines in the data graphs represent the thresholds of the corresponding order parameters.