Fabrication of a pyramidal micro-needle array structure using 3D micro-lens mask lithography

This paper presents a novel fabrication process for a pyramidal microneedle array using contact exposure and a micro-lens mask. This method accurately controls the geometric profile of a pyramidal microneedle array without the need for an etching process. The pyramidal microneedle utilizes a microlens array mask with geometrical optics. Light passes through the microlens and a square hole in a Cr film of the mask and this light is then transmitted through the microlens’ glass and radiated onto the photoresist film. Finally, the light that is transmitted through the microlens is aligned to a focal point on the photoresist film. The exposure mode characterizes the optical performance of the machined microneedle, which is then compared with theoretical data. The experimental results show that the length of the pyramidal microneedles are close to result that is predicted by the optical system calculation formula. A pyramidal mcironeedle of using a specific height and diameter for the microlens allows the fabrication of the photoresist pyramid. A pyramidal mcironeedle array is especially suited to the delivery of drugs.