Bulk Micromachined Titanium Microneedles

Microneedle-based drug delivery has shown considerable promise for enabling painless transdermal and hypodermal delivery of conventional and novel therapies. However, this promise has yet to be fully realized due in large part to the limitations imposed by the micromechanical properties of the material systems being used. In this paper, we demonstrate titanium-based microneedle devices developed to address these limitations. Microneedle arrays with in-plane orientation are fabricated using recently developed high-aspect-ratio titanium bulk micromachining and multilayer lamination techniques. These devices include embedded microfluidic networks for the active delivery and/or extraction of fluids. Data from quantitative and qualitative characterization of the fluidic and mechanical performance of the devices are presented and shown to be in good agreement with finite-element simulations. The results demonstrate the potential of titanium micromachining for the fabrication of robust, reliable, and low-cost microneedle devices for drug delivery