Direct and simple upcycling of reclaimed carbon fiber into flexible tactile sensor with tilted microhair arrays

This study explores the development of a tactile sensor utilizing reclaimed carbon fibers (rCFs) arranged as a biomimetic tilted microhair array (TMA), offering a sustainable approach to reduce carbon footprints and promote circular economy principles. The TMA-based sensor, inspired by the structure of animal fur, demonstrates notable sensitivity to both pressure and shear forces, key to replicating skin-like tactile sensing. Through an innovative fabrication process, rCFs were aligned and pressed into a tilted array on a flexible substrate, forming a highly ordered structure with anisotropic properties. The sensor exhibited a wide pressure detection range from 0.02 kPa to 13 kPa, with a maximum sensitivity of 24.00% kPa⁻¹. Additionally, its response to shear forces reveals distinct anisotropic properties, enabling precise differentiation between axial and radial directions. The underlying sensing mechanism, driven by changes in intrinsic and contact resistance, was analyzed to elucidate the sensor's response to mechanical stimuli. Overall, the functionality of sensor is closely linked to its innovative use of rCFs, which addresses common challenges in recycling by transforming these fibers into a valuable sensing technology.