This research work investigates the development and application of process fingerprinting for conventional micro-injection moulding and ultrasonic micro injection moulding manufacturing of microneedle arrays for drug delivery. The process fingerprinting method covers in-depth analysis, interrogation and selection of certain process data features and correlation of these features with product fingerprints which are defined by the geometrical outcomes of the microneedle arrays in micro scale. The method was developed using the data collected using extensive sensor technologies attached to the conventional and ultrasonic micromoulding machines. Moreover, a machine vision based microneedle product evaluation apparatus is presented. Micromachining capabilities of different processes is also assessed and presented where state-of-the-art laser machining was used for microneedle tool manufacturing in the work. By using process fingerprinting procedures, conventional and ultrasonic micromoulding processes has been characterised thoroughly and aspects of the process that is affecting the part quality was also addressed for microneedle manufacturing. It was found that polymer structure is of paramount importance in obtaining sufficient microneedle replication. An amorphous polymer have been found to be more suitable for conventional moulding whereas semi-crystalline materials performed better in ultrasonic micromoulding. In-line captured micromoulding process data for conventional and ultrasonic moulding provided detailed insight of machine dynamics and understanding. Linear correlations between process fingerprints and micro replication efficiency of the microneedles have been presented for both micromoulding technologies. The in-line process monitoring and product quality evaluation procedures presented in this work for micro-injection moulding techniques will pave ways for zero-defect micromanufacturing of miniature products towards Industry 4.0.

There is an urgent need for improvements to existing vaccine delivery technologies to run parallel with the development of new-generation vaccines. The burdens of needle-based immunisation strategies are exacerbated by poor resource provision in such areas as sub-Saharan Africa, where annual malaria mortality stands at 860,000. Needle-free delivery of vaccine to the skin holds promise for improved immunogenicity with lower doses of vaccine, in addition to significant logistical advantages. Various methods have been described for the transcutaneous delivery of vaccines, including the use of microneedles to overcome the outer stratum corneum of the skin for efficient delivery of liquid or solid, microneedle-coated vaccines into underlying strata rich in antigen-presenting cells. This thesis aims to evaluate two transcutaneous silicon microneedle and microprojection patch technologies for the delivery of live recombinant Adenovirus and Modified Vaccinia Ankara-vectored vaccines encoding pre-erythrocytic malaria antigens in mice. Cellular immunogenicity directed against a well-documented epitope of the Plasmodium berghei circumsporozoite protein is evaluated, as is protection against lethal P. berghei sporozoite challenge. Immunological and logistical benefits of each technology are assessed, as well as mechanisms underlying differences in the generation of a patch-induced immune response to vaccination. These data inform the future development of transcutaneous microneedle patches for the delivery of live vaccine.

<p>This thesis highlights the use and significance of surface enhanced Raman spectroscopy (SERS) for forensic applications. Two unique SERS substrates are developed for successful (1) forensic toxicological drug detection in human patient plasma and (2) trace explosive detection.  </p>