Responsive materials architected in space and time

Architected materials are a class of materials with structures intermediate in scale between atomic arrangement and bulk dimensions; this additional degree of freedom enables unique properties and functionalities. This Review describes the state of the art in architected materials that are responsive to various stimuli. Rationally designed architected materials have attained previously untapped territories in materials property space. The properties and behaviours of architected materials need not be stagnant after fabrication; they can be encoded with a temporal degree of freedom such that they evolve over time. In this Review, we describe the variety of materials architected in both space and time, and their responses to various stimuli, including mechanical actuation, changes in temperature and chemical environment, and variations in electromagnetic fields. We highlight the additive manufacturing methods that can precisely prescribe complex geometries and local inhomogeneities to make such responsiveness possible. We discuss the emergent physics phenomena observed in architected materials that are analogous to those in classical materials, such as the formation and behaviour of defects, phase transformations and topologically protected properties. Finally, we offer a perspective on the future of architected materials that have a degree of intelligence through mechanical logic and artificial neural networks.

Automated summary

Architected materials are a class of materials with unique properties and functionalities. They have structures intermediate in scale between atomic arrangement and bulk dimensions, and can respond to various stimuli and evolve over time. This review provides an overview of the architected materials constructed in both space and time, and discusses their responses to different stimuli.