Enhancing durable electrical conductivity in multi‐walled carbon nanotubes‐epoxy composites via laser repetition rate nanojoining for flexible electronics

Abstract With the development of nanotechnology, laser matter interaction has become intriguing for many applications, including the manufacturing of flexible electronics to improve interface behaviors. Employing high laser repetition rate nanojoining transfer patterning, this study ensures the robust and consistent stability of electrical properties of MWCNTs. This procedure meticulously eliminates contaminants from the interface between flexible PET substrates and carbon nanotube‐containing epoxy, significantly influencing the degree of alteration in composite material and interface behaviors. By increasing the laser repetition rate from the original sample to the sample irradiated by a laser with a repetition rate of 80 kHz, the defect concentration in carbon nanotubes decreases from 0.448 × 10 6 /nm 2 to 0.39376 × 10 6 /nm 2 , respectively. The relationship between defect concentration and electrical conductivity in semiconductor carbon nanotubes under laser irradiation is multifaceted and context‐dependent. Optimizing the laser repetition rate is crucial in defining the kind and density of semiconductor carbon nanotubes. This study found an electrical conductivity of 3.6799 × 10 −4 S/m at a laser repetition rate of 80 kHz. Laser ablation nanojoining with a high laser repetition rate is poised to become a key recycling method for plastic materials in future industries. When MWCNTs are used in processing new materials, this method not only enhances the electrical and mechanical properties of recycled plastics but also creates high‐performance composites with added value. Additionally, the quick nature of this process helps minimize toxicity in material processing by reducing exposure time and the need for harmful chemicals. These composites exhibit superior properties suitable for advanced applications such as flexible electronics, sensors, and nanocomposite materials, contributing to both sustainability and economic value in various industrial sectors.