Combining Laser-Induced Graphene with Kirigami for Transparent Flexible Electromagnetic Interference Shielding

This study presents a method for creating effective electromagnetic interference (EMI) shields that are transparent, lightweight, and flexible, which is vital to address the needs of emerging flexible electronics. By integrating laser-induced graphene (LIG) with kirigamia technique of cutting and folding polymer filmsspatial patterns of highly conductive 3D porous graphene is produced. The entire fabrication utilizes a single laser system for both LIG and cutting, which makes the direct-write process versatile and scalable. The resulting 3D graphene is highly conductive with resistance under 25 ohm/mm and good quality with G/D ratio at 1.66 and 2D/G ratio at 0.46. The films achieve an EMI shielding efficiency (SE) over 50 dB at a low density of 0.04 g/cm^∧3. By leveraging the kirigami process to tune the SE and transparency, we achieve an SE of 17 dB while maintaining over 80% transparency, which exceeds previously reported values of 2D graphene. Additionally, our results address challenges in the flexibility and weight of EMI shields, achieving an exceptional EMI specific shielding efficiency (SSE) of 1362.2 dB cm³/g, competing with the previously reported values across thicknesses ranging from 10 to several hundred micrometers.