Uniformly connected conductive networks on cellulose nanofiber paper for transparent paper electronics

Abstract

Paper has been used throughout history for numerous purposes and continues to be extremely useful. The cellulose-based material has even been investigated as a support for flexible electronics. Traditional paper, however, does not provide the transparency that is increasingly sought after in this field. Now, Hirotaka Koga, Masaya Nogi and co-workers from Osaka University, Japan, have coated a type of transparent paper that they previously developed with conductive materials. Their paper is based on cellulose nanofibers rather than the microfibers from which traditional paper is composed. The team used silver nanowires or carbon nanotubes as the conductive material—both show promise in transparent flexible electronics that employ plastic substrates. By depositing the silver or carbon on the ‘cellulose nanopaper’ through a simple filtration process, the researchers obtained uniform networks, thus avoiding the uneven distribution that typically occurs with plastic-based substrates. The resulting flexible materials showed good conductivity and optical transparency.