Using a technique inspired by kirigami, the Japanese art of paper cutting, engineers at the University of Pittsburgh have created transparent barriers that block and absorb electromagnetic interference (EMI) while remaining flexible enough to fold. The researchers have harnessed the power of a single laser to both carbonize and cut polymer films, patterning laser-induced graphene (LIG) into intricate honeycomb designs.<\/p>\n
The breakthrough, detailed in the recent article \u201cCombining Laser-Induced Graphene with Kirigami for Transparent Flexible Electromagnetic Interference Shielding<\/a>\u201d (DOI: 10.1021\/acsaenm.5c00861<\/a>) and featured on the cover of ACS Applied Engineering Materials<\/a>, could protect the next generation of connected electronics and medical sensors from the invisible electromagnetic noise and harmful radiation that increasingly fill our wireless world.<\/p>\n \u201cOur work shows how laser processing of materials and nanocarbon synthesis can intersect beautifully,\u201d said Mostafa Bedewy<\/a>, associate professor of mechanical engineering and materials science<\/a> and principal investigator of the NanoProduct Lab<\/a> at Pitt.<\/p>\n \u201cWe use precise laser energy to convert everyday polymer films into porous networks of conductive graphene right where we want them, without \u00a0additional chemicals or complex vacuum systems,\u201d Bedewy added. \u201cThis research opens doors for scalable manufacturing of next-generation polymer-based shielding materials.\u201d\u00a0<\/p>\n The research demonstrated that the patterned graphene films could maintain over 80 percent transparency while still achieving adequate shielding efficiency. These EMI shielding capabilities are typically seen in opaque metallic coatings. \u00a0<\/p>\n Importantly, the team shows that when folded into multilayer configurations, the polymer-graphene films exceeded 50 decibels of EMI shielding efficiency, which is comparable to dense metal foils but with a fraction of the weight.<\/p>\n \u201cIt\u2019s exciting to see that a simple, one-step laser process can make something both elegant and functional,\u201d said Mirza Sahaluddin, a PhD student in Pitt\u2019s Department of Mechanical Engineering and Materials Science, and first author of the paper. \u201cOur kirigami patterns let us tune transparency and shielding by design, almost like engineering origami for electromagnetic waves.\u201d<\/p>\n This project represents an interdisciplinary collaboration at Pitt, with researchers from three engineering departments in the Swanson School working together to design, manufacture, and characterize these novel materials.<\/p>\n \u201cElectromagnetic interference is becoming a hidden but serious issue as electronics multiply in our daily lives,\u201d said Paul Leu<\/a>, professor in the Department of Industrial Engineering<\/a> and co-author of the study. \u201cTransparent shielding materials like these could be critical for protecting sensors, medical devices, and communication systems from cross-talk or radiation exposure.\u201d<\/p>\n