The present invention provides a method for fabricating patterned cellulose nanocrystal (CNC) composite nanofibers and thin films for optical and electromagnetic sensor and actuator application, comprising the following steps of: selecting materials for fabricating patterned cellulose nanocrystal (CNC) composite nanofibers; and fabricating patterned CNCs composite nanofibers by incorporating secondary phases either during electrospinning or post-processing, wherein the secondary phases may include dielectrics, electrically or magnetically activated nanoparticles or polymers and biological cells mechanically reinforced by CNCs.