Artificial Life in-materio: Creatures in a Nanomagnetic Metamaterial.

Artificial life in-materio is the exploration of emergent life-like phenomena within physical material substrates. A rich variety of physical phenomena may support life-like behaviours, exploiting fundamentally different principles than biology. Here, we uncover life-like behaviours in artificial spin ice, a nanomagnetic metamaterial. In artificial spin ice, virtual creatures can be defined as spatio-temporal magnetic patterns that exist in the collective state of interacting nanomagnets. Pairing magnetic simulations with a genetic algorithm, we discover a diverse set of creatures, with behaviours including still life, oscillators and gliders. Beyond our initial discoveries, we show that a subset of the creatures can coexist under the same conditions, opening for the possibility of complex interactions. Finally, we provide a physical real-world experimental demonstration of two simple creatures interacting. In artificial life in-materio we strive to find the life that arises naturally within a material, transforming exotic materials into potentially habitable worlds.