The first fully printed electronics

Abstract

Printing digital devices with inkjet technology usually involves steps beyond the printer, such as rinsing or curing in an oven. Now, researchers have made the first fully printed transistors—ones that emerge with all their components in place, ready to be used (ACS Nano 2019, DOI: 10.1021/acsnano.9b04337). To make the devices, Aaron D. Franklin of Duke University and his colleagues used a technique called aerosol jet printing to deposit layers of ink on paper and plastic substrates. This printing method breaks up ink into microscopic droplets, minimizing the amount of background solvent so that unwanted material does not need to be rinsed off or evaporated outside a printer. The researchers first printed carbon nanotubes to form the conductive channel of a transistor and then printed electrodes using water-based silver nanowire ink. Next they applied a layer of hexagonal boron nitride flakes mixed with hydroxypropyl methylcellulose to serve as an insulator. Finally,