Microneedles explores the design, fabrication and use of microneedles for drug and vaccine delivery. This book discusses the contemporary status of the field, describing several areas in detail, including the distinct types of microneedles (dissolving, solid, coted, hollow and hydrogel-forming). The anatomy of the eye is also described to facilitate an understanding of microneedle-assisted ocular drug delivery. Finally, the book provides a detailed discussion of microneedle use in the field of diagnostics, with a chapter dedicated to the mathematical modeling of microneedle-mediated drug delivery.