3D Printed Flexible Polymeric Metamaterial Constructs for Biomedical Applications: A Review

Abstract

Additive manufacturing has revolutionized the fabrication of functional metamaterials, offering unprecedented design freedom to program mechanical responses through geometric architecture. This review examines the recent advancements in 3D printed polymeric metamaterials for biomedical applications, specifically focusing on flexible systems that move beyond high-stiffness metallic or ceramic constructs with orthopedic applications. We provide a systematic overview of common metamaterial architectures and their implementation across five biomedical domains: (1) sensing and wearables, where lattices enhance sensitivity and linear range; (2) soft robotics and 4D printing, focusing on active, stimulus-responsive movement; (3) tissue simulation, utilizing architected tissue phantoms for medical training and device development; (4) tissue engineering, where porous scaffolds govern cellular behavior; and (5) drug delivery, leveraging increased surface-area-to-volume ratios for optimized release kinetics. This review highlights the various strategies employed by researchers to overcome the limitations of bulk polymers through innovative design and novel materials integration. Finally, we discuss future perspectives, including the role of inverse design and computational modeling, the integration of multi-modal sensory and actuation behaviors, and the need for long-term biocompatibility and fatigue characterization in clinical settings.