A metamaterial is a material engineered to have a property that is not found in nature. Many different types of metamaterials have been widely researched across a variety of fields. The materials are usually constructed from a repeating pattern of unit cells, whose behavior is largely driven by the design of the mechanical structure and geometry configuration. In recent years, the advancements in micro-fabrication and micro-manipulation technologies, especially in micro-additive manufacturing technologies, provide new possibilities for the fabrication of metamaterial microstructure with embedded actuators and sensors. Unlike most existing microarchitectured metamaterials that exhibit their properties based solely on their microstructure's topology and constituent material properties, active microarchitectured metamaterials exhibit the desired behavior through the incorporated actuators. In addition to producing the desired material properties accurately, active microarchitectured metamaterials are also capable of real-time tuning and arbitrary control of such properties, providing more flexibilities for the application of metamaterials.

This research aims to provide general design guidelines for active microarchitectured metamaterials. The dissertation begins by reviewing the main methods for designing microstructure's topologies based on compliant micro-mechanisms. This is followed by a discussion of the microstructure's actuation design principles, including the optimal placement of actuators and the selection of micro-actuation physics. A numerical computational tool is then introduced that identifies the boundaries of the performance capabilities achieved by a specific design topology and generates the parameters that produce the optimal design instantiations. Examples of active microarchitectured metamaterial design are introduced and optimized to demonstrate such design principles.