Nanoscale carbon for print-in-place and recyclable electronics

A.D. Franklin
Duke University,
United States

Keywords: recyclable electronics, carbon nanostructure, CNS, nanomaterials

Summary:

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 1D carbon nanotubes, 2D graphene and hexagonal boron nitride, and quasi-1D silver nanowires. 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 ºC with most processing occurring at room temperature. To achieve this, significant advancements were made to minimize the intermixing of printed layers, drive down sintering temperature, and achieve sufficient thin-film electrical properties. Devices are demonstrated on various substrates, including paper, and evidence of the potential for printing directly onto biological surfaces will be shown. What’s more, recent progress towards a completely recyclable printed transistor will be discussed, fabricated entirely using carbon-based inks.