Laser induced graphene for EMI shielding and ballistic impact damage detection in basalt fiber reinforced composites

Basalt fiber has been widely used in a variety of industries due to its unique properties and relatively low cost. However, the nature of electrical insulation of basalt fiber limits its application in the field of functional composite materials such as electromagnetic interference (EMI) shielding materials. Laser-induced graphene (LIG) is a form of three-dimensional carbon nanomaterial, which could be generated by scribing a laser on many carbonaceous precursors. In this work LIG film obtained by double-sided etching Polyimide (PI) paper was embedded in the basalt fiber laminates to fabricate multi-functional basalt fiber composites. The effects of LIG film insertion on Mode I and Mode II fracture toughness and out-of-plane ballistic impact resistance of basalt fiber laminates were investigated. The basalt fiber laminates with LIG inserted retain their original mechanical properties in terms of fracture toughness and impact resistance. While the conductivity and electromagnetic shielding performance of basalt fiber laminate after LIG insertion have been greatly improved. The EMI shielding effectiveness of the basalt fiber laminates is increased to -20 dB after one layer of LIG was inserted, and to -50 dB after three layers of LIG were inserted, for the X-band frequency range. The damage localization of the basalt fiber laminates was demonstrated by arraying the rectangular LIG strips in the shape of hash key and in-situ monitoring the electric resistance changes.