Hydraulic Resistance of a Novel Hollow-Core Microneedle Design

In recent years, developments in microscale fabrication have enabled the creation of needles on the scale of micrometers. These “microneedles” can be created out of a variety of materials and facilitate highly accurate small volume fluid delivery with minimal tissue disruption. Studies have shown that diameter and insertion force are primary determinants of patient pain caused by transdermal injection [1]. The small diameter of microneedles reduces the invasiveness and patient sensation associated with their clinical use. Microneedles have been used for enhancing skin permeability to drug delivery patches, transdermal infusion, and intrascleral inoculation [2–5].