Fabrication of a hollow needle structure by dicing, wet etching and metal deposition

We previously proposed a novel fabrication process, which combined mechanical dicing and anisotropic wet etching, to reduce the cost of micro-electro-mechanical system devices, and fabricated various solid-type microneedle structures using this process for trans-dermal drug delivery systems. The current research involved us enhancing our previous processes by applying metal plating and using a minimum number of photolithography steps, and we fabricated a hollow-type micro-needle structure, in which a flow channel was formed at the center of the needle projection, for supplying medical solutions from the area behind the needle. We fabricated two different shaped needle structures, pyramidal and flattened needles. The height and pitch of both needle types were 120–250 µm and 230–280 µm, respectively. The developed process is useful for producing disposable microneedles for bio-medical applications.