**10. Results and discussions**

**Figure 4** shows one of the micro-funnels which have been fabricated using the abovementioned method. The micro-funnels were designed to have a sharp tip and wide top, that is a low aspect ratio geometry. This design allows a larger amount of drug to be encapsulated per microfunnel. The conical geometry used in this study had a volume in excess of 24.4 nl. In addition, the micro-funnels were found to have sufficient mechanical strength for inserting into the

**Figure 4.** Photo illustrating a fabricated micro-funnel.

human skin. The smallest tip diameter which has been achieved in this study is within 50 μm, which is sharp enough to pierce the human skin.

The proposed fabrication methodology can be further improved and extended to realize other more complicated systems involving 3D micro-structures.
