Rubik’s cube as in-situ programmable matter and a reconfigurable mechanical metamaterial

As part of the 4th industrial revolution, programmable mechanical metamaterials exhibit great application potential in flexible robotics, vibration control, and impact protection. However, maintaining a programmed state without sustaining the external stimulus is often challenging and leads to additional energy consumption. Inspired by Rubik’s cube, we design and study an in-situ programmable and distribution-reconfigurable mechanical metamaterial (IPDR-MM). A matrix model is developed to model IPDR-MMs and describe their morphological transitions. Based on this model, the reinforcement learning method is employed to find the pathways for morphological transitions. We find that IPDR-MMs have controllable stiffness across several orders of magnitude and a wide range of adjustable anisotropies through morphology transformation. Additionally, because of the independence of the directions of morphology transformation and bearing, IPDR-MMs exhibit good stability in bearing and can readily achieve high stiffness. The Rubik’s cube-inspired design concept is also instructive for other deformable structures and metamaterials, and the current version of the proposal should be sufficiently illustrative to attract and broaden interdisciplinary interests.