Off-Stoichiometry Thiol-Ene (OSTE) Hollow Microneedle Array for Liquid Collection and Delivery

As an emerging microtechnology, microneedles have been widely used for liquid sampling and drug delivery. Here, we fabricate a hollow microneedle array by diffraction lithography of OSTE, which can easily control the features of microneedles, including height, diameter, and pitch distance. Furthermore, we integrate the microneedle array with a soft PDMS microfluidic chip, which can generate negative pressure for liquid collection from the skin, as well as positive pressure for liquid delivery into the skin by finger pressure. In addition, we have tested the performance of the integrated chip in terms of repeatability and capacity. We believe this work can provide design guidelines for hollow microneedle chips used for sample collection from skin and drug delivery through skin.