Fig. 6: Environmental responsiveness of Robo-Matter.

a Adaptivity of Robo-Matter in response to external stimuli. Left panels show the snapshots of a reversible active crystal to disordered gas-like phase transition induced by an isovolumetric compression and decompression cycle (Supplementary Movie 2). The right panel shows the evolution of h₆ and the nearest-neighbor number change rate n_nc during the process. The stages I, II, III, and IV, respectively corresponds to the relaxed state before compression, the compression process, the decompression process, and the relaxed state after compression. b Structural self-optimization of Robo-Matter in a rapidly changing environmental field. Left panels show the snapshots of a rapid re-organization and self-optimization of an active glass-like phase with disordered structures into an ultra-stable active crystal phase in response to a sharp increase-decrease of the light intensity (Supplementary Movie 2). The right panel shows the evolution of h₆ in response to a square impulse of light intensity profile. The red and green lines in the snapshots 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. The shaded regions in the data graphs represent the standard deviations, and the background colors indicate different phases. All the repeated experiments have been performed three times.