OVERVIEW
Our lab specializes in the study of structural colouration in organisms (current focus on terrestrial arthropods) that are responsible for vivid hues such as many (ultra)violets, blues, greens. and even reds in both extant and extinct organisms. Such colours are ubiquitous in nature and form an important part of the phenotype of animals, as they are often used in inter- and intra-sexual communication and camouflage. Specifically, we are interested in what we have termed “Evolutionary Photonics” – an integrative understanding of the evolutionary origin, functional ecology, structure-function relationships and morphogenesis of self-assembled organismal photonic nanostructures – to inform the biomimetic, facile and sustainable synthesis of advanced functional materials at the hard to achieve mesoscopic (visible optical) length scales.
We are thus broadly focused on the integration of evolutionary biology, developmental biology, and soft matter physics to inform fundamental questions from animal signalling to the bio-inspired or biomimetic design of novel, eco-friendly, functional materials by mimicking the ‘green’ water-based intra-cellular self-assembly processes. Towards this end, we are keen on developing and applying an ‘-omics’ approach to unravel the precise developmental basis of animal structural colouration in non-model organisms. We are also very much interested in comparative, macro-evolutionary questions on the evolution of iridescent and non-iridescent structural colouration in nature, questions that are well-poised to be presently addressed given the recent phylo-genomics driven progress in systematics.
We have pioneered the use of synchrotron Small Angle X-ray Scattering (SAXS) as a precise, high-throughput tool for the structural characterisation of biophotonic nanostructures. We also routinely use electron microscopy (both scanning and transmission), focused ion-beam milling and are keen on applying a whole slew of state-of-the-art materials characterization techniques including X-ray nanotomography and ptychography, Raman spectroscopy, microspectrophotometry, fibre diffraction in tandem with theoretical optical modelling approaches for the structural and functional characterisation of biophotonic materials.
We are thus broadly focused on the integration of evolutionary biology, developmental biology, and soft matter physics to inform fundamental questions from animal signalling to the bio-inspired or biomimetic design of novel, eco-friendly, functional materials by mimicking the ‘green’ water-based intra-cellular self-assembly processes. Towards this end, we are keen on developing and applying an ‘-omics’ approach to unravel the precise developmental basis of animal structural colouration in non-model organisms. We are also very much interested in comparative, macro-evolutionary questions on the evolution of iridescent and non-iridescent structural colouration in nature, questions that are well-poised to be presently addressed given the recent phylo-genomics driven progress in systematics.
We have pioneered the use of synchrotron Small Angle X-ray Scattering (SAXS) as a precise, high-throughput tool for the structural characterisation of biophotonic nanostructures. We also routinely use electron microscopy (both scanning and transmission), focused ion-beam milling and are keen on applying a whole slew of state-of-the-art materials characterization techniques including X-ray nanotomography and ptychography, Raman spectroscopy, microspectrophotometry, fibre diffraction in tandem with theoretical optical modelling approaches for the structural and functional characterisation of biophotonic materials.
Structure and Function of Biophotonic Nanostructures
3D photonic nanostructures in terrestrial arthropods span the lyotropic/amphiphilic phase space!
We have been at the forefront of accurately (both structurally and optically) characterizing the diversity of photonic nanostructures in birds and terrestrial arthropods. By contrast to most studies on animal structural coloration that look at a handful of species at most, we seek to understand their function and evolution from a broad macro-evolutionary perspective. We utilize the latest techniques like USAXS that help us appreciate the often complex three-dimensional nature of these biophotonic nanostructures. Our approach in comparing "kindred forms" and in studying the forces that has given rise to them (inspired by D'arcy Thompson) has led us to the startling insight that these biophotonic nanostructures are self-assembled intracellularly and rival the morphologies seen in synthetic polymeric materials, including such elusive and esoteric phases like the single gyroid and plumber's nightmare.
Phase-separated channel (spinodal-like) and sphere-type (nucleation-and-growth-like) morphologies in structurally colored bird feather barbs
Evolution and Development of Biophotonic Nanostructures
Self-assembly of single gyroid photonic crystals in butterfly scale cells via membrane folding and templating
Structural colours have evolved over millions of years of selection for a consistent optical function. Having unlocked the nanostructural secrets of avian and arthropod biophotonic nanostructures, we are interested now in understanding how organisms have evolved to facilely develop these nanostructures via intra-cellular self-assembly at the large optical length scales, both from a micro- and macro-evolutionary perspectives, informed also by the fossil record.
700,000 years of structural color in the weevil Hypera
Biomimetics and Bioinspiration of Nature's Multi-functional Nanostructures
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Currently, the fabrication of a designer, defect-free, large-area photonic crystals via synthetic amphiphile or lyotropic self-assembly is very challenging. Nature has pre-empted engineering and has in many instances arrived at optimal solutions to our current problems in sensing and communication, using (self-assembled) biophotonic nanostructures. We are very interested in harnessing this innate ability of cells to self-assemble to develop novel biomimetic and bioinspired routes for the design and synthesis of novel nanostructures for multi-functional applications from sola cells, fibre-optics to cosmetics and textiles. |
Open-Source Software (OSS) available on github
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bbandAgmodel
This repository contains the software implementation for Prakash et al. 2021 Cell Reports "Antennapedia regulates metallic silver wing scale development and cell shape in Bicyclus Anynana butterflies." This includes a set of code written in SCM Scheme, awk and shell (Bash) and using FreeSnell to theoretically model the broadband (silver/gold) reflectivity of a bilaminate butterfly wing scale scale with 3-layers (an air layer sandwiched between upper and lower laminae). |
