Linear and Post-Buckling Analysis of Biocompatible Polymer Microneedle for Transdermal Drug Delivery

To facilitate the delivery of drugs into the skin structure, microneedles play a pivotal role. Unlike conventional hypodermic syringes, microneedles penetrate only the dermis layer, avoiding nerve receptors and resulting in a painless injection. However, when a drug is administered into the skin, microneedles may undergo bending and buckling, leading to structural failure. Such failure can cause the drug to remain beneath the skin, potentially creating complications. Preventing the catastrophe of microneedle failure necessitates a close examination of parameters involved in the bending and buckling process. In this paper, we focus on buckling analysis, as the majority of microneedle failures are attributed to the buckling effect. We perform buckling analysis through finite element analysis to predict the critical buckling load (Pcr). This analysis helps determine the maximum load that a microneedle can withstand. We conduct this analysis using two modes: linear and non-linear (post-buckling analysis). By varying the tip diameter of the microneedle (20µm, 40µm, 60µm, 80µm, 100µm), we can identify the safe insertion load.