Graphitization on Natural Biopolymer Shellac: Toward Substrate Independent Coatings and a Recyclable Flexible Heater

Extraction of graphene and graphene derivatives from non-toxic, biocompatible, eco-friendly, and biodegradable resources with a one-step production process is a challenge. This work is the first attempt at the one-step graphenization of Shellac, a biopolymer derived from natural resources, achieved using direct laser patterning. Interestingly, the process highlights substrate independence by producing reduced graphene oxide (rGO) from multiple substrates, such as glass slides, Copper (Cu) adhesive tape, and overhead projector (OHP) plastic films. The produced rGO is fully characterized, and it is found that the sheet resistance is as low as 5.4., 24.65, and 8.4 Ω Sq⁻¹. on the glass slide, OHP plastic sheet, and Cu adhesive, respectively. Moreover, developing various logos on resin-coated ceramic tiles demonstrated the possibility of patterning desired conductive rGO patterns. Furthermore, a recyclable flexible rGO/Shellac heater is fabricated to validate its electrothermal performance (117.3 °C at 9.5 V) with foldable stability. The proposed one-step substrate independent two-material fabrication will revolutionize the process, potentially replacing conventional toxic routes of graphene production.