Calligraphy‐Brush‐Fabricated Xuan Paper for Sustainable Direct‐Current Triboelectric Nanogenerators in Human‐Motion Energy Harvesting and Biomedical Sensing

ABSTRACT

This study presents a sustainable direct current triboelectric nanogenerator fabricated from PEDOT:PSS‐coated Xuan paper using a traditional calligraphy brush method. The combination of Xuan paper, a biodegradable, renewable, and culturally significant material, with a traditional brush‐based fabrication method provides a sustainable strategy for energy harvesting applications. The water based PEDOT:PSS/PVA/pullulan conductive ink allows gentle and uniform coating, while the soft bristles of the brush enable deep penetration into the cellulose fiber network, forming a smooth, continuous, and flexible conductive layer. The resulting Al/PEDOT:PSS interface exhibits a built in potential difference of approximately 0.9 eV, enabling efficient charge transfer and rectified direct current generation. The device achieves an open circuit voltage ( V _oc ) of about 0.75 V, a short circuit current ( I _sc ) of 300 μA, and a maximum power density of 41.4 μW cm ⁻² under a 2 N mechanical load. It also demonstrates stable electrical outputs under various human motions such as finger tapping, elbow bending, and heel pressing. This work establishes a novel and eco‐friendly strategy that merges traditional art techniques with sustainable material science, advancing biodegradable and self‐powered energy harvesting systems.

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