Investigation of interactions between high pulsed ultraviolet lasers and composite graphene/AgNWs films

Highlights: • High-pulsed UV lasers was used to ablate electrode structures for strain sensors. • The UV laser ablation threshold of graphene/AgNWs films was about 0.157 J/cm². • The strain sensor with an electrode width of 0.1 mm had the largest G_F of 13.47. • The strain sensors were used in the real-time bending test of wind turbine blades. • The graphene/AgNWs-based strain sensors exhibited an excellent response and recovery. To improve the joining strength and electrical conductivity, this study aims to develop an ultraviolet (UV) laser annealing to join AgNWs coated on polyethyene terephthalate substrates. The developed graphene/AgNWs-based strain sensors with UV laser-ablated electrodes were highly promising for in situ structural health monitoring of wind turbine blades. After the UV laser annealing, the rate of resistance changes of laser-annealed AgNWs had a minimum value of −2.92 ± 1.0 % when the laser power set at 0.4 W. Moreover, the sheet resistances of laser-ablated graphene/AgNWs films increased with increasing the laser areal fluences. The laser areal fluence of 10.88 J/cm², pulse repetition frequency of 200 kHz, scan velocity of 400 mm/s, and line scan pitch of 0.02 mm were used to ablate the graphene/AgNWs electrode structure of strain sensors. During the bending test, the graphene/AgNWs-based strain sensors with an electrode width of 0.1 mm had the largest gauge factor of 13.47. Furthermore, the graphene/AgNWs-based strain sensors demonstrated an excellent response and recovery during the real-time bending test of wind turbine blades.