Light manipulation in diatoms - from basic mechanisms towards the design of multi-functional, hybrid photonic devices

Photonic devices are pervasive in human life, spanning telecommunication, healthcare, energy production, and sensing.

Nowadays single devices can simultaneously manipulate several optical parameters for diverse functions, but they require high-cost nanofabrication facilities for their production.

Conversely, nature offers zero-cost, ordered dielectric nanostructures which various animals, plants and protists exploit for light manipulation, optimizing inter- and intra-species communication, camouflage, or solar light harvesting.

Notably, diatoms, ubiquitous unicellular microalgae, deserved to be referred to as "living photonic crystals" due to the resemblance of their silica walls (frustules) to artificial ones.

Frustule ultra-structure efficiently interacts with optical radiation through multiple diffractive, refractive, scattering, waveguiding, and frequency down-conversion mechanisms, which can explain diatoms´ efficiency in photosynthesis and UV tolerance, and potentially can be related to phototaxis mechanisms of raphid (motile) species.

In a multidisciplinary team, the proposed research aims to deepen the understanding of diatom photonic properties by identifying the specific optical functionalities associated to the individual frustule components.

In vivo experiments will further elucidate the potential frustule biological role in photosynthesis, photoprotection, and phototaxis, while lying the foundation for the design of multifunctional, bio-derived photonic devices.