Enhancing electrochemical performance of colorless polyimide-derived laser-induced graphene via gold nanoparticles integration: Towards advanced wearable and energy harvesting applications

In addressing the limitations of traditional laser-induced graphene (LIG) derived from colored polymers, our research pivots to the utilization of colorless polyimide (CPI) for LIG fabrication, aiming to leverage CPI's optical transparency for enhanced applicability in advanced technologies. Despite CPI-based LIG (C-LIG)'s potential, its electrochemical performance has lagged behind that of pure graphene, prompting a need for performance enhancement. Our study introduces novel oxygen plasma treatment and multi-step laser process- ing techniques, underpinned by ReaxFF molecular dynamics simulations, to integrate gold nanoparticles (AuNPs) into the C-LIG matrix, creating Au-C-LIG. These methodologies yielded electrochemical improvements, with surface potential and work function increases from 4.70 to 4.94 eV, enhancing the triboelectric effect. Validation through SEM, XPS, XRD, and TEM analyses confirmed these enhancements. Furthermore, the Au-C-LIG-based pressure sensor demonstrated exceptional sensitivities of 27.56 kPa−1 (0-3 kPa), 6.97 kPa−1 (3-7 kPa), and 0.65 kPa−1 (7-25 kPa), alongside rapid response/recovery times of 38/35 ms, surpassing existing graphene-based sensors. The introduction of these novel fabricating techniques enhances the potential of C-LIG and improves its applicability in the realms of wearable devices and energy harvesting.