Dermal microneedles have emerged as transformative and highly accessible technologies for both non-invasive drug delivery and biosensing applications. In this research direction, we design microneedle platforms to either sample dermal interstitial fluid (IF) biomarkers or deliver drugs in a painless and rapid manner. Ultimately, our MNs can be designed to overcome many limitations facing conventional diagnostic and drug delivery strategies including the invasive and complex nature of blood-based biosensors, the first pass metabolism limiting oral drug administration, and the largely impermeable stratum corneum limiting topical drug administration.