Arrays of solvent cast hollow out-of-plane polymer microneedles for drug delivery

Microneedles are tiny hollow structures that allow painless drug delivery into human skin. In this work, we present a novel fabrication method for microstructures based on solvent casting that allows rapid fabrication of inexpensive microneedles from polymer materials. The polymer microneedles are formed on a reusable mold made with a single photolithography step. The strength of the fabricated microneedles under compressive loading was investigated. The capability of the microneedles for drug delivery was also demonstrated by injection of fluorescent beads into rabbit ear skin and inspection of the penetration depth using confocal microscopy.