Environment-Friendly\nTriboelectric Nanogenerator Based\non 3D-Printed Nanocellulose Films for Human Motion Monitoring

Triboelectric nanogenerators (TENGs) have drawn much\ninterest in\nself-powered sensors or wearable electronics, particularly those based\non nanocellulose (NC) films fabricated by manual casting. Herein,\nwe introduce the 3D-printing technique to directly 3D-print (3DP)\nNC suspension on polycarbonate substrates, followed by cleanroom drying\n(relative humidity: 45%; temperature 25 °C). The 3DP NC films\nshow high flexibility, transparency, a tensile strength of 139.92\n± 5.3 MPa, a Young’s modulus of 5.74 ± 0.32 GPa,\nand a strain at break of 6.13 ± 0.15%, much higher than manually\ncast NC films (tensile strength: 66.29 ± 8.12 MPa; Young’s\nmodulus: 4.02 ± 0.11 GPa; strain at break: 2.42 ± 0.09).\nEco-friendly 3DP NC films, without surface modification, are used\nto fabricate 3DP-NC-TENGs, demonstrating output powers of 16.85 μW\nat 20 Hz and significantly higher outputs of 19.4 μW at the\nsame frequency, surpassing previously reported manually cast NC film-based\nTENGs. Finally, the 3DP-NC-TENG is applied as a self-powered sensor\nthat demonstrates stable and sustainable performances across various\nhuman motion monitoring, such as walking (4.38 V), jumping (26.7 V),\nand finger tapping (9.4 V). 3D-printing technology can be preferred\nover traditional manual casting methods for fabricating environmentally\nfriendly and high-performance NC-based TENGs.