Cello relies in the use of cellulose and derivatives for photonic applications , opening new pathways for one of the most abundant biopolymers on the earth.
Transparent materials can exhibit exciting optical properties if they present a nanostructure with dimensions similar to that of the incident light. This is the case of the well-known photonic crystals, periodic dielectric materials in which light propagation is described in terms of photonic bands and photonic bandgaps. One of the most interesting properties of these architectures is the exhibition of bright colors without the existence of pigments or dyes (hence, they will not fade over time). Using biocompatible materials to produce photonic structures will result in architectures that can control the flow of light in the material while being biocompatible, bioresorbable and even transient or edible. My group has demonstrated that cellulose, the most abundant biopolymer on earth, has also great potential for photonics as summarized in our 2018 publication in Nature Photonics 20189. In our work, we fabricated hydroxypropyl cellulose based photonic and plasmonic crystals by nanoimprinting lithography, resulting in films with bright colors that can serve for SERS sensing or feature water solubility. Molding materials is a simple task with the aid of nanoimprinting lithography, a technique in which a pre-patterned elastomer is used as a stamp to deform a thin film of a wide range of materials while compatible with roll to roll fabrication processes. Furthermore, our variation of NIL used in our group requires no cleanroom, since we perform the imprint process in a chemical lab. In this project, we prepare and characterize different photonic films from cellulose and demonstrate the versatility and potential of this biopolymer for optical applications.
