On a microfabricated Ti-alloy-based microneedle array for transdermal drug delivery

Transdermal drug delivery is a promising approach that allows controlled release of drug over time while avoiding possible degradation due to the gastrointestinal tract or first-pass liver effect. Of many different methods have been employed in transdermal drug delivery, microneedle is a widely explored MEMS-based device that can conveniently penetrate the skin and thus create micrometer-scale openings for drug absorption. In this paper, we attempt to study a Ti alloy-based microneedle array, particularly its fluidic features, through a series of simulations using ANSYS. The results indicate that, provided the volumetric flow rate is constant, the pressure of inlet decreases when the flow rate of inlet increases; the flow rate of outlet increases with the increase of pressure of inlet when flow rate of inlet is set to constant. In both scenarios, a complete description of liquid flow through microneedle conduit should consider in vivo effects such as the liquid absorption in the epidermis and the mechanic feature.