Improved 3D-Printability of Cellulose Acetate to Mimic Water Absorption in Plant Roots through Nanoporous Networks

Developing artificial plant root models to mimic water absorption using biomaterial-derived inks for three-dimensional (3D) printing is challenging because of their rheological behavior and biocompatibility. Herein, we developed and optimized a cellulose acetate (CA) ink and its printing parameters for extrusion-based 3D-printing to fabricate an object that mimics the mechanical properties and water absorption ability of plant roots. The composition and printing parameters of the CA ink were correlated to its rheological properties for enabling the uninterrupted printing of structures with layer thickness of 0.1 mm and high shape fidelity. The 3D-printing process produces a highly nanoporous (∼87 nm diameter) material without altering the chemistry of CA. The Young's modulus (1.43 ± 0.14 GPa) and tensile strength (23.30 ± 2.40 MPa) of 3D-printed CA are comparable to those of real plant roots. Furthermore, its high hydraulic conductivity of 3.9 × 10–4 m s–1 MPa–1 indicates its superior water absorption ability. Thus, the 3D-printed CA material possesses immense potential for application in plant science and bioengineering.