( Invited ) Spatiotemporal Process Control in Laser-Induced Graphene for High Performance Electrochemical Interfaces

Laser-induced graphene (LIG) has emerged as a versatile platform for flexible electrochemical devices, but simultaneously achieving low impedance, high spatial resolution, and scalable fabrication remains challenging, especially without relying on post-processing or additives. In this invited talk, I will present a unified view of our recent work on understanding and exploiting process–structure–property relationships in LIG to engineer nanocarbon electrochemical interfaces. First, I will discuss our miniaturization strategy for patterning LIG microelectrodes with critical dimensions well below the nominal laser spot size for commercial CO 2 lasers. By employing a toner-printing step before lasing, we control proximity effects in heating, which enables defining narrow conductive features. The resulting microelectrodes combine lateral dimensions in the tens of micrometers with low resistance and robust adhesion on flexible substrates, enabling dense arrays suitable for high-resolution sensing. Second, I will show how sequential laser irradiation (“relasing”) can be used as a purely process-based route to drastically lower electrochemical impedance. Using a two-pass strategy with slower second-pass scanning, we couple kinetically controlled carbonization with enhanced graphitization, achieving roughly an order-of-magnitude reduction in electrochemical impedance compared to conventional single-pass LIG. Our results reveal increased graphitic crystallinity, reduced heteroatom content, and a highly cratered, high-surface-area morphology, consistent with the observed improvements in electrical resistivity and charge-transfer characteristics. Accordingly, we demonstrate sensitive detection of dopamine at sub-25 nM concentrations. Together, these results illustrate how laser processing parameters can be used as powerful knobs to tailor the morphology, chemistry, and electrochemical performance of LIG, paving the way for scalable manufacturing of nanocarbon-based biosensors, neural interfaces, and other electrochemical devices.