Flexible and Anisotropic Strain Sensor Based on Carbonized Crepe Paper with Aligned Cellulose Fibers

Abstract Here, a highly flexible and anisotropic strain sensor based on sustainable biomass‐derived materials is fabricated through a facile, low‐cost, and scalable approach. The commercially available crepe paper made of the abundant and renewable cellulose is converted into a conductive network by carbonization. The fabricated strain sensor based on this carbonized crepe paper (CCP) exhibits high flexibility, fast response time (10 000 cycles), and negligible hysteresis. Especially, the CCP strain sensor shows dramatically different gauge factors (10.10 and 0.14, respectively) between tensile bending perpendicular and parallel to the fibers direction. This anisotropic sensing performance is inherited from the crepe paper's unique anisotropic structure, i.e., aligned cellulose fibers and a corrugated surface, which is well maintained in the CCP. In addition, the CCP strain sensors' practical use in detecting complex human motions and controlling a 2‐degree‐of‐freedom machine is demonstrated, indicating their potential applications in multidimensional wearable electronics and smart robots.