Rapid fabrication of highly customizable solid microneedle arrays

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There are many drawbacks to hypodermic needles, such as insertion pain, tissue trauma, and expertise needed to perform an injection. Microfabricated microneedle arrays promise painless blood extraction and drug infusion by penetrating only the upper part of the skin, avoiding the nerves. Solid microneedles are coated with a therapeutic agent, allowing the drug molecules to dissolve into the surrounding tissue after penetrating the skin barrier. The dosage depends on the microneedle area and therefore the yield is limited. Microfabrication methods are ideal to create solid microneedle arrays, as the materials are biocompatible, robust and designed for large-scale integration with other micro manufacturing processes. We have demonstrated a new method to make solid microneedle arrays. This proof of concept manual fabrication method is tedious, unreliable and greatly impedes the innovation cycle, taking ~5 minutes to make a single microneedle when hundreds are needed. Working with vendors of automated wire bonders, we have shown that the process can be decreased to ~1 second per microneedle. However, having a sample made by a vendor is costly (several thousand dollars per device), and takes up to a month for delivery. This greatly impedes the experimental investigation needed for this research, where hundreds of device iterations need to be tested and experimentally validated. The requested automated wire bonder will provide dedicated access for my students, allowing for efficient and reliable fabrication of new designs of large area, high-density arrays in a repeatable, reliable, cost efficient, and extremely timely process (devices can be made and tested the same day). This will greatly increase our research productivity and maintain our competitive edge. The requested automated wire bonder will directly support the training of my HQP who are investigating methods to overcome the solid microneedle yield issue through integrating microfluidic channels next to the base of the solid microneedles, in part supported by my Discovery Grant. Without this equipment we will not be able to investigate large scale arrays for the delivery of relevant amounts of liquid into the area next to the perforated skin. As our microneedles are metal and individually electrically addressable, the ability to increase the uptake of drugs through the process of electroporation and iontophoresis will be investigated. The bonder will be housed in a multi-user cleanroom facility, with experienced technicians maintaining the equipment, extending its operational lifetime and facilitating HQP training. The equipment will be utilized extensively for the current research program and, when idle, will be available to other researchers thereby increasing their research productivity. Long-term this research will move from the bench to the bedside, by creating a solid microneedle system that can be used without direct medical supervision, thus reducing healthcare expenditure.