Sustainable structural materials with light weight, great thermal dimensional stability, and superb mechanical properties are vitally important for engineering application, but the intrinsic conflict among some material properties (e.g., strength and toughness) makes it challenging to realize these performance indexes at the same time under wide service conditions. Here, we report a robust and feasible strategy to process cellulose nanofiber (CNF) into a high-performance sustainable bulk structural material with low density, excellent strength and toughness, and great thermal dimensional stability. The obtained cellulose nanofiber plate (CNFP) has high specific strength [~198 MPa/(Mg m⁻³)], high specific impact toughness [~67 kJ m⁻²/(Mg m⁻³)], and low thermal expansion coefficient (<5 × 10⁻⁶ K⁻¹), which shows distinct and superior properties to typical polymers, metals, and ceramics, making it a low-cost, high-performance, and environmental-friendly alternative for engineering requirement, especially for aerospace applications.

Petroleum-based plastics are useful but they pose a great threat to the environment and human health. It is highly desirable yet challenging to develop sustainable structural materials with excellent mechanical and thermal properties for plastic replacement. Here, inspired by nacre’s multiscale architecture, we report a simple and efficient so called “directional deforming assembly” method to manufacture high-performance structural materials with a unique combination of high strength (281 MPa), high toughness (11.5 MPa m^1/2), high stiffness (20 GPa), low coefficient of thermal expansion (7 × 10⁻⁶ K⁻¹) and good thermal stability. Based on all-natural raw materials (cellulose nanofiber and mica microplatelet), the bioinspired structural material possesses better mechanical and thermal properties than petroleum-based plastics, making it a high-performance and eco-friendly alternative structural material to substitute plastics.

Advanced materials that can remain electrically conductive under substantial elastic stretch and bending have attracted extensive interest recently owing to their broad application potentials, particularly for flexible electronics. Here, we have developed a simple and inexpensive method to fabricate highly conductive and stretchable composites using bacterial cellulose (BC) pellicles as starting materials, which can be produced in large amounts on an industrial scale via a microbial fermentation process. The prepared pyrolyzed BC (p-BC)/polydimethylsiloxane (PDMS) composites exhibit a high electrical conductivity of 0.20–0.41 S cm⁻¹, which is much higher than conventional carbon nanotubes and graphene-based composites. More importantly, the p-BC/PDMS composites that combine high stretchability with high conductivity show great electromechanical stability. Even after 1000 stretching cycles at the maximum strain of 80%, the resistance of the composites increased by only ∼ 10%. The resistance increased slightly ( ∼ 4%) after 5000 bending cycles with a maximum bending radius of 1.0 mm.