High-Resolution R2R-Compatible Printing of Carbon Nanotube Conductive Patterns Enabled by Cellulose Nanocrystals

Abstract

Carbon nanotubes (CNTs) with enhanced properties compared to conventional materials are a leading material of choice for fabricating next-generation electronic devices. Nanocellulose-based conductive component-enabled electronics also offer great potential for commercial scalability of environmentally friendly, sustainable, flexible, wearable electronics. Printing these functional materials through R2R printing will enable the economic and high-throughput production of next-generation electronic devices. However, the lateral resolution during R2R printing of these materials is currently limited due to the enhanced aggregation behavior of these high-aspect ratio particles, and the lower lateral resolution limits the performance of the fabricated devices. This article demonstrates high-resolution, R2R-compatible printing of conductive patterns of CNTs using cellulose nanocrystals (CNCs) through the topographical discontinuous dewetting and liquid-bridge transfer patterning technique. The CNC dispersion obtained through acid hydrolysis of spinifex grass biomass was used as a sustainable functional ink and deposited as a structural wetting layer, which necessarily allowed the subsequent deposition of a conductive CNT layer to form high-resolution conductive patterns. Conductive patterns with lateral feature sizes down to ∼4.5 μm were reliably printed and those with feature sizes down to ∼925 nm were also possible. The high-resolution conductive CNC/CNT patterns could be printed on different hydrophilic substrates, including flexible, transparent CNC films, for use in devices. This study represents a proof-of-concept for the realization of the economic and environmentally friendly printing of high-resolution nanocellulose/carbon-based electronics.