Stiffness reprogrammable magnetorheological metamaterials inspired by the spine for multi-bit visual mechanical information processing

Embedding information processing into mechanical metamaterials is conducive to constructing multifunctional mechanical systems, which have unique advantages to provide information processing platforms in extreme environments. However, achieving high-density, reprogrammable, and visually readable information processing in most mechanical metamaterials remains a challenge. Here, we report a multi-bit programming spine structure strategy to create a magnetorheological metamaterial with high-density, reprogrammable, and visually readable information encoding capacities. Inspired by spine features, the magnetorheological spine beams, exhibiting substantial stiffness variation by bi-stable transition, are meticulously conceived as the stiffness reprogrammable magnetorheological metamaterial (SRMM). The SRMM exhibits a large stiffness conversion capability (40-fold) and high-density information encoding performance (10-bit). Coupling with the mechanoluminescent materials, the mechanical information achieves visualization conveniently, which is attributed to the conversion of the stiffness data into optical signals through optical energy level transitions. Such stiffness-based magnetorheological metamaterial offers expansive information encoding spaces, stable operation capabilities, and convenient readout approaches, advancing mechanical information processing system design for extreme environments.