Main Focus
Photonic Structures in Nature
Color is omnipresent in nature, with animals and plants evolving sub-micrometer structures that manipulate light to create vivid and iridescent hues. This type of coloration, known as structural coloration, does not rely on pigments but instead arises from various photonic mechanisms such as multilayered materials, crystalline inclusions, and surface diffraction gratings. A remarkable example of intense iridescent coloration in plants is found in the fruits of Pollia condensata. The striking color of these fruits is due to Bragg reflection from helicoidally stacked cellulose microfibrils, which form multilayers in the epicarp's cell walls. Their bright blue hue is more vibrant than that of many other biological materials. Uniquely, the reflected color varies from cell to cell because the thickness of the layers in the multilayer stack differs, giving the fruit a distinctive pixelated or pointillist appearance.
Another remarkable example is the Cyphochilus beetle, native to Southeast Asia, which boasts a whiteness surpassing that of paper. This extraordinary brightness is due to the ultra-thin scales that cover its body. Recent research into the optical properties of these scales has revealed that they scatter light more effectively than any other known biological tissue, enabling the beetle to achieve such a brilliant white appearance.
Symbiotic Materials for improving Light Management
More recently my research focus has moved in the direction of the understanding how living unicellular organisms build symbiotic relationships to synergistically manipulate light and to develop new hybrid materials combining functional living building-blocks within synthetic matrices. I believe that by bridging the gap between artificial and living matter, we can produce materials that have radically new functionalities “borrowed” from living organisms, which can be challenging to achieve with only synthetic systems alone. Additionally, such novel hybrid systems, being composed of cells and bio-compatible and bio-based matrices, will be inherently biodegradable and hence more sustainable.