Nature’s coloured materials and bioinspired applications

This project aims to understand the structures that produce vivid colours and enable rapid colour change in certain beetles. Beetle wing coverings (elytra) are composed of chitin with structures at the nanometre and micron scale that produce vivid colours and diverse optical effects such as metallic and mirror-like appearances. They are the ideal models to understand structurally coloured biomaterials.

The structure and colour change mechanism in specific beetle groups are of particular interest for bioinspired materials and sensors, but the biology remains poorly understood. There is a great deal we don’t yet know about specific mechanisms and the material properties (e.g. mechanical properties) and how they are optimised for different functions. This project will reveal novel material properties in beetles, which can be used to improve the design of the next generation of sustainable biomaterials.

In particular, in the project, we will work on two distinct structural systems in beetles;

• The layered helicoidal 'twisted-plywood' structures in scarab beetles (Scarabidae). Helicoidal structures are widespread in nature and have many advantages, including high mechanical strength and fracture resistance, and the ability to produce vivid metallic and iridescent colours.
• The mechanism of colour change in some leaf beetles (Chrysomelidae). In contrast to scarab beetles, some chrysomelid beetles have the ability to rapidly change colour, likely by controlling humidity within multilayers within the cuticle.

Each of these systems have specific advantages and potential applications. The outcomes of the project will be i) novel insights into the biology of colour and ii) developing a model for bio-inspired coloured materials. The Melbourne component will involve experimental work on beetles and a range of high-end microscopy. The Manchester component will involve fabrication and characterisation of chitin-based materials inspired from the biological structures discovered at Melbourne. This PhD offers a unique opportunity to combine biological discovery with real-world application.