Biodegradable Laser Arrays Self‐Assembled from Plant Resources. Issue 29 (14th June 2020) - Guo, Jiaqi
Abstract: The transition toward future sustainable societies largely depends on disruptive innovations in biobased materials to substitute nonsustainable advanced functional materials. In the field of optics, advanced devices (e.g., lasers or metamaterial devices) are typically manufactured using top‐down engineering and synthetic materials. This work breaks with such concepts and switchable lasers self‐assembled from plant‐based cellulose nanocrystals and fluorescent polymers at room temperature and from water are shown. Controlled structure formation allows laser‐grade cholesteric photonic bandgap materials, in which the photonic bandgap is matched to the fluorescence emission to function as an efficient resonator for low threshold multimode lasing. The lasers can be switched on and off using humidity, and can be printed into pixelated arrays. Additionally, the materials exhibit stiffness above typical thermoplastic polymers and biodegradability in soil. The concept showcases that highly advanced functions can be encoded into biobased materials, and opens the design space for future sustainable optical devices of unprecedented function. Abstract : The study demonstrates sustainable, switchable, and biodegradable laser devices self‐assembled from cellulose nanocrystals (CNCs) as the resonator and dye‐doped water‐soluble polymers as the gain medium.