The utilization of environmentally conscious approaches not only in material selection but also in manufacturing process is introduced in this study. By leveraging a ternary Deep Eutectic Solvent (DES) system with desirable properties (choline chloride, citric acid, and acrylic acid), we have achieved cellulose nanofibrillation and polymerization in one-pot approach which minimizes waste and extra steps commonly seen in isolation of commercial cellulose nanofiber production. The novel polymerizable DES system facilitates the nanofibrillation of pineapple leaf fiber in the range of 1-30 nm with preserved crystalline structure of cellulose. The stable dispersions of the biomass-containing system were further evident with the esterification of the cellulose hydroxyl groups after the treatment. The addition of cellulose-based biomass allows the composite to exhibit a yield point and achieve shear-thinning behavior, which is necessary for direct ink writing (DIW) 3D printing applications. The in-situ polymerization of the acrylic monomers within the system generates soft viscoelastic materials with self-adhesive properties which opens up the vast potentials for sensor based applications utilizing green approaches.