Out-of-plane micro-needle arrays using silicon micromachining

An array of out-of-plane silicon processed micro-needles has been successfully fabricated using relatively simple fabrication techniques. This abstract describes the methods explored to produce 100-element needle arrays (10times10) on a single die. Applications of the micro-needles include transdermal drug delivery and tissue delivery (during surgery). Two types of needles were fabricated: solid electrode and hollow through-hole. The solid-core micro-needles can be used for painless perforation of the skin layer to increase absorption of drugs through patches. These types are fabricated using only oxidation, dicing and isotropic etching. The hollow versions have more applications for direct delivery of drugs through the skin and require additional steps of lithography and deep reactive ion etch (DRIE).