David joined the CDT in February 2015 having previously completed a Masters in Physics at Queen's University Belfast.
CDT PhD Project:
Optimisation of a Gold Nanorod Plasmonic Structure
Dr Bob Pollard, Queen's University Belfast
Dr David Childs, University of Glasgow
Arrays of gold nanorods can be fabricated using magnetron sputtering, anodisation and electrodeposition techniques and these sensor chips then make use of a phenomenon known as localised surface plasmon resonance (LSPR). This is where light incident on nanostructures composed of a noble metal - gold in this case - couples to quasiparticles called plasmons.
A closely related phenomenon - surface plasmon resonance (SPR) is already in use as the key technique in creating certain biosensors, but LSPR offers many advantages, chiefly that the surrounding hardware is considerably simpler, not requiring the calibration or complexity that an SPR-based system does. This opens the door to cheaper and more portable hardware.
The work executed in this project is centred around the deposition of the trilayer stack that forms the first step of the manufacturing procedure, followed by characterisation of the finished stack and using that information to optimise the thin-film deposition process to better withstand hostile environments. The work has implications for any device utilising LSPR, from those in life sciences to magnetic recording and communications.