Flow-Assisted Ultrasonic Exfoliation Enabling Scalable and Rapid Graphene Production for Efficient Inkjet-Printable Graphene Ink

Abstract

Achieving high efficiency in graphene production and printing process simultaneously is challenging, but it needs to be addressed as it is critical for realizing the commercial viability of printed graphene devices. This study successfully substantiates these requirements by significantly improving the efficiency of graphene production and subsequently developing an inkjet-printable graphene ink that enables the rapid formation of the percolation network of graphene flakes. The integration of a flow coil reactor into an ultrasonic bath results in scalable and rapid graphene production, with graphene productivity up to three orders of magnitude higher than conventional liquid-phase exfoliation (LPE), offering the potential that ultrasonic LPE can benefit the scalability and simplicity of graphene production. In addition, the graphene ink, optimized by ink formulation, has a stable high graphene concentration of 3.5 g L–1, resulting in the formation of stable percolation networks of graphene flakes only after two printing passes under optimized printing conditions. The printed graphene patterns are also confirmed to be conformable to various substrates and durable against repeated stretching and bending stress. By ensuring high efficiency in graphene production and inkjet-printable ink preparation, this study would promote the commercialization of graphene production and the resulting printed graphene devices.

Sensitivity-Enhancing Strategies of Graphene Field-Effect Transistor Biosensors for Biomarker Detection

“…42,43 Despite LEG's advantages in producing high-quality graphene with minimal defects, its limitations include the randomness of the flake size distribution and the tiny average size required by some printing methods, like inkjet printing. 44,45 In contrast to the "top-down" fabrication, the "bottom-up" fabrication, includes such as chemical vapor deposition (CVD) and physical vapor deposition (PVD). Conventional CVD processes involve the decomposition of precursors (such as CH 4 ) at high temperatures (900 °C), adsorption and deposition of gaseous atoms on the substrate, and the formation of a continuous film through surface chemical reactions.…”

“…Wang et al. utilized LEG-based FETs to modify single-stranded DNA for DNA methylation assessment, further developing a GFET biosensor for single-stranded DNA detection with a notable detection limit of 10 fM. , Despite LEG’s advantages in producing high-quality graphene with minimal defects, its limitations include the randomness of the flake size distribution and the tiny average size required by some printing methods, like inkjet printing. , …”