Modular assembly system for multi-dimensional 3D-structured hollow microneedle array device

Abstract This paper presents a novel, energy-efficient assembly approach for fabricating precision 3D-structured hollow microneedle devices and introduces an automated modular assembly system to validate its efficiency. The proposed method decouples the manufacturing processes of the microneedle body and base. The hollow microneedle body with complex internal channels is fabricated using high-resolution 3D printing, while the microneedle base can be produced using a low-resolution 3D printer or injection moulding with a 50 μm resolution. Standard connection interfaces (e.g., thread, Luer, or barb connectors) are integrated into the microneedle base design to enable easy coupling with syringes or other pumping devices. A customized modular assembly system is then developed to rapidly assemble these components into ready-to-use hollow microneedle array devices. The 10 mm/s feedrate assembly system installs each needle in less than 27 s, reducing production time by over 68% and manufacturing cost by 56% for a 19-microneedle array device compared to the full 3D-printing method. The production time can be further reduced by implementing a parallel assembly strategy, minimizing airtime, and optimizing the feedrate. Further, this modular assembly system achieves a reduction of more than 72% in electricity consumption and CO₂ emissions, validating its energy-efficiency and environmental sustainability. To validate the reliability of this method, compression test, bending test, and fluid leakage test were conducted on the produced microneedle devices, which proves eligible performance. The proposed approach largely reduces manufacturing cost and production time while allowing flexible fabrication of a variety of micro-structured components with different geometries, materials, and functionalities, not only for microneedle devices. This work helps bridge the final gap in the practical translation of microneedle arrays technology to real-world applications.