Metamaterials
Metamaterials or architected materials are man-made materials that derive their properties from a careful structural design on smaller scales. The engineering properties of conventional materials emerge as the macroscale consequence of various microstructural features and mechanisms from the atomic scale through the micro- and mesoscales all the way up to the macroscopic scale. By contrast, the microscale in metamaterials is an engineering structure itself, made by the priodic, random or quasi-periodic arrangement of structural members such as beams, plates and shells. The resulting macroscale properties in this case are a direct consequence of the architectural features (besides the properties of the base material used to create the architecture). By methods of 3D printing such metamaterials are readily available via additive manufacturing and the infinite design space of small-scale architectures offers unlimited opportunities for tailoring material properties by demand.
We strive to understand, enrich, and exploit the design space of metamaterials, ultimately resulting in novel architected materials systems with as-designed properties. Mechanical properties of interest include, e.g., the material's stiffness, strength, and fracture toughness, or the material's ability to guide and attenuate mechanical stress waves. In addition, we create smart and active metamaterials which change their shape upon actuation by an external stimulus.
Applications range from stiff lightweight structures for aviation to biomimetic bone implants with physiologically-optimized properties to wave guides and mechanical sensors to impact absorbers for sports gear and protection.
In our approach, we combine theory, simulations, and experiments. Starting with theoretical concepts and exploiting finite-element, phase-field or discrete numerical simulations, we explore the design space and the physical phenomena achievable through carefully engineered metamaterial architectures. Fabricating and characterizing prototypes allows us to fine-tune their architecture and behavior while also serving as proof-of-concept realizations of the novel functionality and material performance.