(A*STAR Programme) Micro-pattern formation and photonic sintering of conducting structures in optical materials

University of Manchester Supervisor: Dr Patricia Scully. A*STAR Supervisor: Shan Xuechuan (SIMTech).

This PhD project is a collaboration between the University of Manchester Photon Science Institute (PSI) and the Process Technology Team at the Singapore Institute of Manufacturing Technology. It will explore photonic sintering based on ultrafast laser inscription techniques to create conducting structures in novel optical materials using silver and copper nanoparticles and Graphene:

1. Within non-standard optical substrates such as polymers and composites
2. As a one-step “green” and chemical-free ambient photonic process, replacing high temperature annealing, clean room or gas controlled atmospheres, lithography or post processing to remove metal substrates.
3. In 3D to create sub-surface structures.

The PhD project will explore new materials and inscription of conducting structures using lasers, and explore their scale-up into manufacturing processes. Current processes for printing electronic circuits requires multiple process steps, that are unable to be adapted for reel-to reel systems, and the new materials now required such as flexible substrates, and low temperature substrates such as polymers. Current production techniques are not “Green” and require complex etching and chemical steps.

This project will explore large area micro-pattern formation to form optical components and photonic sintering of conducting structures in optical materials. Micro-pattern formation will be realized by using imprinting and/or printing technologies, and photonic sintering will be implemented using energy delivered by light sources such as UV flash light or lasers into materials doped with nano-particles, to bonding of nanoparticles together to form bulk metal conducting structures. Sintering enables the material to coalesce and behave like bulk material, losing its nanoparticle characteristics. Understanding of the optical and thermal processes is necessary since, if the photonic energy is too high then the metal can evaporate, which is undesirable.

The project will take place in two centres:
At the University of Manchester, in Year 1, the student will explore fundamental laser-material interactions using femtosecond laser suites available at the Photon Science Institute, and create novel materials based on Graphene and metal nano-particle composites. This will include laser inscription of 2 and 3D conducting structures in new materials such as nano-particle metal-insulator composites and graphene, new materials in which the University of Manchester has a track record.

At the A*STAR Research Institute: (years 2 and 3), the student will be based in the Singapore Institute of Manufacturing Technology and will define the process flow for integration into manufacturing process. They will work on micro patterning and photonic sintering on criteria defined at Manchester and optimise the processes. The laser techniques will be adapted to the challenges of large scale manufacturing processes; for example, large area roll-to-roll printing and coating. Scale up of photonic sintering of conducting patterns in nano-particle metal-insulator composites containing Ag and Copper particles, and Graphene composites.

The student will return to Manchester for final experiments, to explore technology transfer between the two centres in the fourth year and writing up their PhD thesis.