Microneedle arrays fabricated using suspended etch mask technology combined with fluidic through wafer vias

We report the fabrication and characterization of microneedle arrays combined with (i) reservoirs for therapeutic or analytic fluids, (ii) sharp edges suitable as cutting and flaring features to increase skin permeability, and (iii) fluidic through wafer connections. Microneedle fabrication relies on a new approach combining deep reactive ion etching of silicon with suspended etch masks. This fabrication technology applies an etch mask which remains suspended above an etch cavity containing microneedle arrays and reservoirs. The structures are intended to enable painless transdermal drug delivery, e.g., application of allergen solutions in allergy diagnostics (Prick test) or of vaccines.