Confirmation of Candidature - Development of Polymeric Microneedles Fabrication Using Injection Moulding Method for Vaccination and Drug Delivery Applications: Mass Production Approach

Microneedles are an alternative to hypodermic needles for drug delivery, vaccination, cosmetic and diagnostic applications. These micron-sized needles present advantages such as sustained release, low logistic expenses, ease of use by unskilled operators, easy disposal, and potential for vaccination in rural areas. Biocompatible polymers are ideal for mass production of microneedles due to their advantages, which include low cost, acceptable mechanical properties, biodegradability, and high chemical stability. This numerical and experimental research aims to develop the fabrication of solid, out-of-plane polymeric microneedle arrays using the microinjection moulding technique. Insertion of microneedles into the stratum corneum of human skin will be simulated to evaluate the impacts of human age, skin thickness, microneedle's polymeric material and shape, and insertion speed on the required penetration force. Apart from geometrical optimisation of desired micro-injected microneedles, the results also provide useful information for optimising future microneedle designs for different human age groups. For injection moulding, Vectra® MT-1300 liquid crystal polymer is selected as the thermoplastic material due to its perfect biocompatibility, low shrinkage, low melt viscosity, and superior mechanical properties. A numerical simulation will be carried out to optimise filling efficiency by adjusting characteristics, including mould and melt temperatures, volumetric injection rate, and injection pressure and speed. The negative mould material selected is Tool Steel 1.2709, which has high hardness, ductility, thermal conductivity, and corrosion resistance. The metal 3D printing method as an additive manufacturing technique will be utilised to fabricate moulds. This is followed by optimal manufacturing of Vectra® MT-1300 microneedles using an injection moulding machine, which has great potential for mass production of highly biocompatible microneedles to solve supply chain problems.

For more information, please email the Graduate Research School or phone 0746 311088.