A Microvascular-Based Multifunctional and Reconfigurable Metamaterial

Abstract

Nearly all-natural and synthetic composites derive their characteristic attributes from a hierarchical makeup. Engineered metamaterials exhibit properties not existing in natural composites by precise patterning, often periodically on size scales smaller than the wavelength of the phenomenon they influence. Lightweight fiber-reinforced polymer composites, comprising stiff/strong fibers embedded within a continuous matrix, offer a superior structural platform for micro-architectured metamaterials. The emergence of microvascular fiber-composites, originally conceived for bioinspired self-healing via microchannels filled with functional fluids, provides a unique pathway for dynamic reconfigurable behavior. Demonstrated here is the new ability to modulate both electromagnetic and thermal responses within a single structural composite by fluid substitution within a serpentine vasculature. Liquid metal infiltration of varying density micro-channels alters polarized radio-frequency wave reflection, while water circulation through the same vasculature enables active-cooling. This latest approach to control bulk property plurality by widespread vascularization exhibits minimal impact on structural performance. Detailed experimental/computational studies, presented in this paper, unravel the effects of micro-vascular topology on macro-mechanical behavior. The results, spanning multiple physics, provide a new benchmark for future design optimization and real-world application of multifunctional and adaptive microvascular composite metamaterials.