Nanocellulose-based materials for photonic applications [Invited]

The escalating demand for optical and photonic devices across various sectors, encompassing energy, sustainability, medicine, information and communication technologies, is catalyzing the pursuit of renewable and eco-friendly materials. From the perspective of materials science, nature polymers emerge as a versatile resource for designing optical and photonics devices, offering unique opportunities for integrating technology sustainability. Among natural polymers, nanocellulose (NC) stands out, presenting boundless opportunities for processing, functionalization, and biological integration. Interest in the direct use and strategic re-engineering of NC as a platform for developing advanced optical and photonic materials has significantly increased over the past decade. This review consolidates recent advancements in the processing of NC-based materials for active photonic devices. Furthermore, it addresses the challenges and delineates directions for further device design and fabrication. We foresee NC playing a pivotal role in facilitating the future exploitation of sustainable, intelligent, implantable, wearable, and multifunctional optical devices.