Paving Smart Roads: Roll-To-Roll Laser Manufacturing of Tar-based Strain Sensor Networks

Smart road calls for the high demand for road health inspection and traffic monitoring. In this work, tar-derived strain sensors with roll-to-roll (r2r) manufacturing are presented. Typical polycyclic heavy hydrocarbons (HHs), coal tar, and steam-cracker tar as feedstocks are promising for extensive chemical and structural heterogeneity. The sensors could respond to tensile deformation with high sensitivity, of which the steam-cracker tar derived-film exhibits a gauge factor (GF) up to 1818 in 0.008%-0.010% strain, suitable for early alarm for cracks and breakage caused by material aging and environmental erosion. The coal tar-derived sensor can be applied for road/bridge loading monitoring, guaranteeing traffic safety greatly. This work can not only provide new ideas for smart road construction, but also highlight the carbon upgradation with assistance in carbon neutrality.