Ordered Micro-Nano Structures: Synergistic Integration of Microneedles and Photonic Crystals for Advanced Biomedical Systems

Abstract

Ordered micro-nanostructures, characterized by their precisely engineered, hierarchical architectures, have emerged as a pivotal class of materials, offering remarkable potential to modulate mechanical, optical, and biological interactions at multiple scales.These advanced materials enable unprecedented control over a variety of physical and chemical processes, providing a foundation for innovations in diverse fields such as biomedicine, optoelectronics, and sensor technologies. Microneedles (MNs) and photonic crystals (PCs) are two such structure-driven systems that have garnered considerable attention for their applications in transdermal drug delivery and optical sensing, respectively. However, despite significant advancements, the field remains fragmented, with much of the research focused on isolated systems, often overlooking the complex relationships between structure, material properties, fabrication methods, and functional outcomes. The integration of these systems into multifunctional platforms remains a challenge due to material compatibility, fabrication complexity, and the need for functional tuning. This review highlights the latest developments in ordered micro-nano-structured systems, with a focus on MNs and PCs, and discusses 2 their functional properties, biomedical applications, and future challenges for achieving hybridization.