Replication of microneedle arrays using vacuum casting and hot embossing

Abstract

The replication of silicon (Si) microneedle arrays via a soft silicone rubber mold into various polymers, namely SU-8, epoxy, cycloolefine copolymer (COC), and polycarbonate (PC) is reported. Vacuum casting and hot embossing are used to fabricate polymer wafers with 98 microneedle array dies with an individual size of 6/spl times/6 mm/sup 2/ each containing 841 microneedles. The same soft rubber mold can be used for both replication methods. Needles with heights of 75 /spl mu/m and 150 /spl mu/m, tip radii and edge radii below 2 /spl mu/m and 1 /spl mu/m, respectively, are excellently reproduced. The application of the needles in allergy testing is demonstrated.