Nondestructive Integration of Laser‐Induced Biomass Graphene for Sustainable Wearable Electronics

Laser‐induced graphene (LIG) circuits hold significant promise for wearable electronics due to their excellent chemical stability and biocompatibility. However, fossil‐derived aromatic precursors are challenged by limited availability and environmental burden, and high energy laser processing damages substrates and hinders separation. Here, we propose a nondestructive strategy that integrates rapid heat dissipation and stress‐free pattern transfer based on a botanical lignin‐based precursor. Guided by the ReaxFF molecular dynamics simulation on the decomposition and reconstruction processes, lignin‐derived LIG circuits with high‐ordered structure and sheet resistance as low as 15 Ω sq −1 are obtained, and allow for complete integration onto a wide range of polymers, including those with ultrathin (20 µm), low‐modulus (69 kPa), and low‐melting‐point (84°C) profiles previously inaccessible. Leveraging the above platforms, six flexible devices irradiating light, electron, and thermal sensing applications are constructed, demonstrating its universality. Last but not the least, lignin offers high biosynthetic yield, closed‐loop recyclability, and excellent biodegradability, achieving an approximately 90% reduction in environmental footprint compared to fossil‐based alternatives.