A multifunctional platform for the production and customization of polymer-based microneedle devices

Polymer microneedles (MNs) have significant potential for use in transdermal delivery and diagnostics applications due to their low cost, versatility, and compatibility with medical grade materials and industrial manufacturing processes. These polymers can also have a wide range of different and desirable properties such as biocompatibility, degradability, and flexibility. To facilitate rapid development of these devices, a multifunctional manufacturing process, easily adaptable to a range of different materials and use cases, would be highly beneficial for research and prototyping purposes. With that in mind, we have developed a multifunctional platform that may be used to produce sharp-tipped microneedle arrays with a variety of substrate materials, mechanical characteristics, electrical properties, and diagnostic functionalities. The paper first presents an outline of the platform concept and the double-sided moulding process that lies at its core, followed by a description of the various add-on steps that are used to customise the geometrical, mechanical, electrical, and functional aspects of the arrays. Finally, we illustrate the versatility of the platform with three exemplars, namely a solid, electrochemically active MN sensor for biomarker diagnostics, a fabric-backed, flexible MN electrode for biopotential monitoring, and a biodegradable array for transdermal drug delivery.