Design and fabrication of a coupled microneedle array and insertion guide array for safe penetration through skin

Ordinary flat hollow tip, microneedles have been designed and fabricated for biomedical MEMS applications. With the facilitation of an insertion guide, the needles can be pushed down through the viable-epidermis with less bending. The microneedle array has the ability of integration with microfluidic devices since the needles are hollow so that the liquid can flow through the holes. 100 microneedles are contained in a 5 × 5 mm² array chip and the same size of another array chip contains 100 insertion guide holes. A standard silicon micromachining process was employed to fabricate both arrays. The shape of microneedle is as simple as a tube so that the designed theories and simulations can be more precise than the complicated shape. The result of testing shows that there was no microneedle broken during the penetration to the skin via the guiding holes. The finite-element analyses of stresses and deformed shapes have been carried out with the explanation of deformed shape and stress occurred in the needle structure.