Microneedles Fabrication by Substrate‐Independent Electrostretching and In‐Situ Focused Electrospray Deposition for Transdermal Drug Delivery

ABSTRACT Universal transdermal drug delivery remains constrained by the material dependencies and fabrication complexities of current microneedle (MN) technologies. Here, we present the innovative substrate‐independent pulsating in situ dried electrostretching (SI‐PIDES) and the in situ focused electrospray deposition (IFED) platform capable of fabricating and precisely coating MNs on flexible, non‐conductive dielectric patches. By leveraging polarized pulsed voltage, these methods enable the mold‐free fabrication of polymeric MNs and the precise coating of drug‐loaded substances onto dielectric MN patches. This novel discovery provides an integrated and simplified workflow for MN patch fabrication. Experimental results demonstrate that SI‐PIDES and IFED produce mechanically robust core–sheath microneedles and gain considerable improvements in deposition accuracy. Multiphysics particle simulations revealed the effects of charge accumulation on the non‐conductive MN and confirmed the crucial role of the polarized voltage in maintaining deposition efficiency. We further demonstrate the practical utility of this platform by synthesizing and coating zinc/magnesium‐doped mesoporous silica nanoparticles as a drug model, which showed excellent biocompatibility and potent antibacterial suppression in in vitro assays. These findings emphasize the potential of our technology as a simple and physics‐driven approach for the development of scalable, next‐generation high‐precision transdermal drug delivery systems.