Surface-microstructured cellulose films toward sensitive pressure sensors and efficient triboelectric nanogenerators.

To achieve environmental sustainability, cellulose-based functional materials have been extensively used in advanced electronic devices, such as pressure sensor and triboelectric nanogenerator (TENG). Here, we fabricate the surface-microstructured cellulose films (M-CFs) by facile regeneration and hot pressing combined with screen mesh templating. Through simple carbonization, the M-CFs are further converted into the surface-microstructured carbonized cellulose films (M-CCFs) with a good conductivity but maintain the original array concave-pits on surface. These constructed microstructures, which are tunable via controlling the screen mesh's aperture, endow the assembled electronics with adjustable and improved working performance. The pressure sensors with M-CCFs as active materials exhibit an enhanced sensitivity in a wide working range and promising potentials for applications in motions detection and healthcare. The TENGs with M-CFs as tribo-positive friction layers demonstrate higher electrical output and an efficient energy harvesting. Our work provides novel insights into the design and construction of cellulose-based functional films for eco-friendly advanced applications.