Toward a configuration design method for mechanical materials

Metamaterials are materials that exhibit behavior that is not observed commonly in nature, but that can be achieved by designing often complex geometric structures. Behaviors such as negative index of refraction, negative Poisson’s ratio, or negative stiffness can be achieved with suitable lattice or other cellular structures at appropriate size scales. Such materials can be used in many applications to achieve functionalities that would otherwise be difficult to realize. Assuming they exist, designers need a design method capable of identifying when metamaterials are suitable to use as a component in a developing system design. In this paper, we present a configuration design method to meet this need. From a selected function, designers should identify a suitable physical principle and model of desired behavior, then these can be matched to metamaterials and their behavior capabilities. Examples are presented using mechanical metamaterials including bistable mechanisms that exhibit negative stiffness and lattice structures that exhibit negative Poisson’s ratio.