Laser fabrication of flexible electrodes for bioelectronics

Bioelectronics lies at the intersection of electronics and biology, enabling real-time signal exchange between living systems and machines. As next-generation applications such as wearable diagnostics, brain-computer interfaces, and closed-loop therapeutic systems desire for soft, miniaturized, and biocompatible platforms, the role of bioelectrodes becomes even more critical. Direct laser writing (DLW) has emerged as a powerful microscale fabrication approach, capable of directly patterning functional electrodes with high spatial resolution on diverse materials. In addition, DLW uniquely offers localized material processing and property modulation, enabling controlled synthesis, phase transition, and surface functionalization. This review presents a comprehensive overview of the underlying mechanisms and advanced material systems that enable DLW. We highlight how DLW enables structural design that impart stretchability and tissue conformity, and how such electrodes are integrated into wearable and implantable bioelectronic systems. Finally, we discuss key challenges and future opportunities for DLW-based bioelectrodes, which are poised to become foundational components of intelligent and adaptive biomedical interfaces.