A variational approach to microneedle design

Microneedle arrays hold tremendous promise for transdermal drug delivery and bio-fluid extraction. Yet, the same features that make microneedles advantageous, i.e., their small overall size and large aspect ratio, make them vulnerable to failure under stresses induced during the insertion process. Maintaining the advantages of size while maximizing the strength through shape variation is the optimization problem addressed in this paper. An indirect variational method is introduced and applied to the microneedle problem. A comparative study of the optimized design versus a typical design is presented.