All-Carbon Nanomaterial Inks for Print-in-Place, Recyclable and Water-Based Electronics

For decades we’ve been hearing about the promise of printing electronics directly onto any surface. However, despite significant progress in the development of inks and printing processes, reports on fully, direct-write printed electronics continue to rely on excessive thermal treatments and/or fabrication processes that are external from the printer. In this talk, recent progress towards print-in-place electronics will be discussed; print-in-place involves loading a substrate into a printer, printing all needed layers, then removing the substrate with electronic devices immediately ready to test. A key component of these print-in-place transistors is the use of inks from various nanomaterials, including: 2D graphene and hexagonal boron nitride, and 1D carbon nanotubes. Using an aerosol jet printer, these mixed-dimensional inks are printed into functional 1D-2D thin-film transistors (TFTs) without ever removing the substrate from the printer and using a maximum process temperature of 80 C with most processing occurring at room temperature. Using a similar print-in-place process, completely recyclable printed transistors will be discussed, fabricated entirely using nanoscale carbon-based inks. These recyclable devices exploit a printed crystalline nanocellulose (CNC) ionic dielectric. Finally, the same set of carbon-based inks will be demonstrated for use in all-aqueous (completely water-based) printed CNT-TFTs, eliminating dependence on processing with harsh solvents. These demonstrations give evidence for an electronic future involving devices with fabrication and/or function that goes beyond what is possible with traditional semiconductor technologies.