Papertronics: Enhanced Density via Laser-Induced Hydrophilic Patterning

Papertronics or paper-based electronics offer a sustainable and cost-effective foundation for nextgeneration flexible and wearable devices. Yet, conventional wax-patterning techniques on hydrophilic paper suffer from uncontrolled wax diffusion, restricting device resolution and reproducibility. Here, we report a laser-induced hydrophilic patterning strategy on hydrophobic paper substrates that completely eliminates wax diffusion. By systematically optimizing the laser power and scanning speed, we created stable hydrophilic regions on hydrophobic paper substrates without inducing thermal diffusion. These well-defined regions enable precise microfluidic deposition of conductive and dielectric materials, facilitating the fabrication of resistors, capacitors, and interconnects. The resulting architectures exhibit markedly improved resolution, reproducibility, and integration density, establishing a scalable and reliable pathway toward next-generation paper-based electronic manufacturing.