Engineering Multifunctional Microneedle Devices: From Advanced Micro‐Nano Manufacturing to Closed‐Loop Theranostics

ABSTRACT

As a turnover technology capable of painlessly breaching the transdermal barrier, microneedles (MNs) have overcome the limitations of solitary transdermal drug delivery, progressively evolving into highly integrated theranostic platforms. Tracing the evolution of bio‐interfacial mass transfer and systemic integration, this review systematically categorizes MN architectures into solid, hollow, coated, dissolving, hydrogel, and layered types, highlighting the critical roles of micromolding, high‐resolution lithography, and three‐dimensional printing in the precise fabrication of MN arrays. In alignment with this technological trend, this review systematically delineates two core trajectories of MN functional evolution and provides an in‐depth discussion on intervention strategies that overcome complex pathological microenvironments to achieve precise targeted drug delivery, while analyzing their sensing potential in situ extraction of dermal interstitial fluid and dynamic monitoring of biochemical biomarkers. Finally, the review explores the manufacturing and production barriers hindering the bench‐to‐bedside clinical translation of MN systems and envisions their promising future evolution toward intelligent closed‐loop theranostic platforms integrating sensing, decision‐making, and therapeutics. Ultimately, an overarching research framework for the MN field that combines systemic comprehensiveness, broad applicability, and introductory guidance is established.