  Metamaterials are artificial structures with unusual and superior properties
that come from their carefully designed building blocks -- also called
meta-atoms. Metamaterials have permeated large swatches of science, including
electromagnetics and mechanics. Although metamaterials hold the promise for
realizing technological advances, their potential to enhance interactions
between humans and materials has remained unexplored. Here, we devise
meta-atoms with tailored fracture properties to control mouthfeel sensory
experience. Using chocolate as a model material, we first use meta-atoms to
control the fracture anisotropy and the number of cracks and demonstrate that
these properties are captured in mouthfeel experience. We further use topology
optimization to rationally design edible meta-atoms with maximally anisotropic
fracture strength. Our work opens avenues for the use of meta-atoms and
metamaterials to control fracture and to enhance human-matter interactions.
