Digital composites with reprogrammable phase architectures.

Spatial patterning of material phases underpins the functional diversity of natural and engineered composites. However, phase architectures are typically fixed once formed, limiting adaptability. Here, we introduce a digital composite with reprogrammable solid-liquid phase architectures at voxel resolution. Each elastomeric voxel contains a liquid metal composite capable of electrically switching between nonvolatile solid and liquid states within seconds, analogous to rewriting data on a hard disk. High-throughput experiments and coupled modeling demonstrate precise tuning of viscoelastic and plastic properties, as well as programmable constitutive behaviors and strain distributions. A modular assembly strategy allows scalable 3D construction of reprogrammable composites into free-form, bulk geometries. By encoding phase states as digital inputs, the composite unlocks unprecedented access to real-time, voxel-level tuning of material properties.