Gianni Iacucci

I received my undergraduate degree in physics from the University of Calabria, Italy. Afterwards, I joined the Department of Chemistry at the University of Cambridge, where I am currently pursuing a PhD under the supervision of Dr Vignolini (complete CV can be found here). My research focuses on light propagation in biological and bioinspired disordered systems.

While periodic structures give rise to a colourful appearance, disordered systems scatter all the visible wavelengths with similar intensities - resulting in white colouration. The study of light propagation in disordered media is relevant both to fundamental and applied problems, ranging from imaging through turbid media to the fabrication of white paint. Scattering in a disordered system is determined by the spatial distribution and the scattering properties of its building blocks. To date, most efforts on scattering optimisation have focused on isotropic, high refractive index systems. Nature, however, provides a prime example of how to exploit anisotropy to achieve scattering optimisation: with the intra-scale chitin network of the beetle genus Cyphochilus (Figure 1).

In my PhD, I combine numerical simulations and experiments to investigate wave transport in anisotropic, disordered media. My research demonstrated that anisotropy allows for improvements in the whiteness of low refractive index media (Figure 1e). Based on this result, my work focuses on the design and characterisation of bioinspired white materials. In particular, the achievement of scattering properties in artificial low refractive index materials (n ~ 1.5) comparable to those found in nature would allow the production of biocompatible and sustainable white materials. 

Figure 1 |  Anisotropic scattering materials. a-d) Images of a white beetle at different magnifications: a) photograph of a specimen of Cyphochilus genus beetle; b) micrograph of the organisation of the scales; c-d) SEM images of a Cyphochilus’ scale from a cross-section and top view, respectively. Insets are the fast Fourier transforms of the SEM images, which show the orientational anisotropy of the chitin network. Scale bar: 1 cm for a, 300 µm for b, 1 µm for c, 2 µm for d.  e) Comparison of the simulated reflectance for systems with building blocks with n = 1.55, same volumes but different aspect ratios.