The maintenance of the Sydney Harbour Bridge presents significant challenges in removing corrosion, aged coatings and surface contaminants efficiently and safely from a large and geometrically complex steel structure. Femtosecond-pulse laser cleaning offers a promising non-contact approach, but translating ultrafast laser–material interactions from laboratory experiments into a practical cleaning technology requires advances in both physics and engineering.

This project aims to develop a prototype femtosecond-pulse laser cleaning platform, establish an optimised cleaning process, and investigate the system-level requirements for practical bridge maintenance. The physics research will focus on understanding ultrafast laser–material interactions governing the selective removal of corrosion and coatings. Key parameters, including pulse energy, fluence, repetition rate, beam size, scanning speed and pulse overlap, will be investigated to determine ablation thresholds, removal mechanisms, thermal effects and potential modification of the underlying steel.

The engineering challenge is to translate this physical understanding into a robust and scalable prototype. This will involve integrating the femtosecond laser source with beam delivery and scanning optics, process monitoring, control, safety and extraction systems. Particular attention will be given to cleaning rate, working distance, surface geometry, process repeatability and operation under conditions representative of the Sydney Harbour Bridge.

The project will establish the relationship between laser physics, cleaning performance and system design, leading to a validated prototype and optimised processing methodology. The outcome will provide a pathway from fundamental ultrafast laser–matter interaction research towards a practical laser cleaning system for large-scale infrastructure maintenance.

This interdisciplinary project is open to students from physics, engineering, and robotics, or related disciplines.

Depending on the student’s background and interests, the project can emphasise laser physics and laser–material interactions, optical and mechanical system development, process control and instrumentation, or robotic integration and automation. 

Experience in experimental laboratory work, programming, optical systems, control, robotics, or mechanical design is advantageous but not essential. Training in femtosecond laser operation, laser safety, laser processing and relevant experimental techniques will be provided.