Fig. 4: MTM Loading and Injection.
a Schematic illustration of the microneedle loading process. Photograph of a 10 × 10 MTM array dipped in rhodamine B solution (scale bar: 2000 μm) with before and after photographs. A schematic diagram of the rhodamine B solution trapped in the MTM interior cavity with an optical microscopy image of a single loaded MTM array (scale bar: 200 μm). b Photograph of the MTM array loaded with the rhodamine B solution on the skin (scale bar: 1000 μm) and cross section illustrating the injection profile of the MTM (scale bar: 500 μm). The optical microscopy image of the cross section for a single MTM injection profile (scale bar: 300 μm)
