Geometrical Accuracy and Strength of Micro-Needles Made of Polylactide by Fused Filament Fabrication Method

Abstract

Additive manufacturing is a technology that can be successfully used in pharmacy and medicine. One of the examples of products that can be additively manufactured are microneedle systems. The specificity of these products, which are used for transdermal drug delivery, makes additive manufacturing a perfect choice for related research. However, the dimensions of microneedles usually do not exceed 2 mm, which means that manufacturing them using the most widely available additive manufacturing method, Fused Deposition Modelling (FDM), is problematic. In this study, the authors decided to investigate the possibilities of manufacturing microneedle systems using the FDM method in such a way as to minimize or exclude the need for post-processing. Five types of microneedle geometries were tested in four sizes, examining how changing the values of FDM process parameters would affect the accuracy of reproducing the digital geometry of the microneedles. From the point of view of the application of microneedle systems, it is not only necessary to obtain the designed shape of the microneedles, but also to maintain their appropriate strength. The study presents the results of the bending and compression strength of microneedles made of polylactic acid.