“Totally-additive-manufacturing”-functionalized carbon fiber-reinforced polymer composites with an ultrasensitive self-sensing network

With recent advancement in multi-material additive manufacturing, we develop a new manufacturing framework driven by the concept of “totally-additive-manufacturing”, to functionalize carbon fiber-reinforced polymer (CFRP) composites with the capacity of in situ, real-time integrity monitoring through service lifespan. It is composed of (i) fused deposition modeling-printed continuous carbon fibers, (ii) nylon-based matrix and electrical insulation layers, and (iii) an ultrathin, aerosol jet printing-fabricated piezoresistive sensing network made with graphene/cellulose nanocrystals nanocomposite ink, as well as the silver ink-based electric circuits. Interfaces among different components are interrogated via micromorphological and interlaminar shear strength tests, affirming adequate interfacial bonding warranted by the “totally-additive-manufacturing”. Thus-functionalized CFRP composites exhibit ultrahigh sensitivity to quasi-static strains induced by cyclic loads and ultrasonic elastic perturbation up to 200 kHz. This study underscores the concept of “totally-additive-manufacturing” for fabricating functionalized composites, seamlessly merging structural functionality with self-sensing of structural health status, but not downgrading the original structural integrity.