Xu, Jie

AbstractA 3D‐printed array of hollow microneedles (HMNs) is designed and fabricated using a high‐resolution stereolithography 3D printer and assembled with a 3D‐printed reservoir that incorporates a Luer lock mechanism, ensuring standard and secure connection to syringes. The proof‐of‐concept needle designs consist of half‐eccentric and concentric conical tip shapes, each arrayed with two different interspacing values. After the geometrical features of the devices are characterized, the devices are tested ex vivo in porcine skin to evaluate the impact of tip shape and interspacing on the depth of penetration and the efficacy of the devices in delivering fluids (such as tattoo ink) into the dermis. Overall, the 3D‐printed HMNs can deliver fluids into the target layer of skin. Refinement of the design is ongoing with the ultimate aim to provide alternatives for intradermal drug delivery and diagnostic imaging, such as superficial lymphography.

Three-dimensional printing technology has been implemented in microfluidic mold fabrication due to its freedom of design, speed, and low-cost fabrication. To facilitate mold fabrication processes and avoid the complexities of the soft lithography technique, we offer a non-sacrificial approach to fabricate microscale features along with mesoscale features using Stereolithography (SLA) printers to assemble a modular microfluidic mold. This helps with addressing an existing limitation with fabricating complex and time-consuming micro/mesoscale devices. The process flow, optimization of print time and feature resolution, alignments of modular devices, and the advantages and limitations with the offered technique are discussed in this paper.