Toward an Internet of Things Circular Economy Using Printed Circuits on Reusable Steel Substrates

Abstract There is a pressing need to reduce electronic waste, which along with government edicts and national time‐bound policy directives are shaping the drive toward circular economy solutions in electronics. However, there is no industrially standardized approach for fabricating high‐throughput recyclable and reusable electronic assemblies. Herein, we present the functionalization of steel over large areas with low‐cost insulative intermediate layers as Printed Circuit Boards (PCBs), enabling an electronics circular economy. Roll‐to‐roll‐friendly reusable steel substrates are coated using Sol–gel‐based low‐roughness insulative layers, with conductive tracks and solder pads additively manufactured with direct‐write printing. To demonstrate how degradable 3D scaffolds could enable wireless applications, RF components, and wi‐fi nodes are demonstrated with 3D‐printed antennas showing the feasibility of broadband Internet of Things applications up to 6 GHz. At their end‐of‐life, the steel‐based PCBs are sonicated in non‐hazardous solvents allowing for the rapid recovery of components and precious metals. The environmental benefits of our approach are discussed using Life Cycle Assessments (LCA) and a comparative LCA between these scenarios has been undertaken. Consideration of the final product cost is given and potential business models to enter the electronics market are identified.