Figure 1.

Active microneedle for enhanced drug delivery. a) Active microneedle patch composition, and built-in Mg particle activation as pumps when in contact with bodily fluids, leading to an enhanced drug release. b) Digital photograph showing a patch of 15 × 15 microneedle array and optical/fluorescent microscopy images of an active MN tip loaded with Mg particles, scale bars, 6 mm and 200 μm, respectively. c) SEM image of single active microneedle tip and EDX analysis for Mg. Scale bars, 300 μm, and 25 μm, respectively. d) Fabrication steps of the microneedle patch: PDMS micromolding over master microneedle, PDMS negative MN mold released, Mg particle loading, polymer and payload inclusion, polymer drying, adhesive application and peel off. e) Microscopy time-frame images taken from a single active microneedle tip clearly showing polymer dissolution in PBS pH 6.0 and particle activation (30 s intervals), scale bar, 200 μm.