Juliet Sackey
University of South Africa, South Africa
Title: Order-disorder on the nanostructures on the ocellus of the Caligo memnon (C& R elder[1867]) butterfly
Biography
Biography: Juliet Sackey
Abstract
The Caligomemnon butterfly has on its ventral under side false ‘eyespot’ (ocellus). On the inner ring of the ocellus are wing scales of black colour. In our quest to unravel the usefulness of this selective solar absorber-like material, the nanostructures on that section of the wing scale were investigated with various techniques. As evident from the scanning electron microscopy images (SEM), the wing scales on the black section contain ridges and lamellae, which show disorder in their shapes and positions. We have analysed and quantify the type of such order-disorder using direct measurement; statistical approach and Fourier transform methods. Based on the autocorrelation of the SEM image and the Hosemann function, an algorithm to compute the line cuts of the order-disorder was developed. The line cuts provided the average values of periodicity, which were used to calculate the porosity in the wing scale. The porosity was found to be the origin of the antireflection property of the black section bio mimicking as selective solar absorber material.