Fabrication of Two-Dimensional and Three-Dimensional High-Resolution Binder-Free Graphene Circuits Using a Microfluidic Approach for Sensor Applications.

In this study, a simple microfluidic method, which can be universally applied to different rigid or flexible substrates, was developed to fabricate high-resolution, conductive, two-dimensional and three-dimensional microstructured graphene-based electronic circuits. The method involves controlled and selective filling of microchannels on substrate surfaces with a conductive binder-free graphene nanoplatelet (GNP) solution. The ethanol-thermal reaction of GNP solution at low temperatures (∼75 °C) prior to microchannel filling (preheating) can further reduce the GNP andprovide a homogeneous GNP solution, which in turn enhances conductivity, reduces sheet resistance (∼0.

Fabrication of High-resolution Graphene-based Flexible Electronics via Polymer Casting.

In this study, a novel method based on the transfer of graphene patterns from a rigid or flexible substrate onto a polymeric film surface via solvent casting was developed. The method involves the creation of predetermined graphene patterns on the substrate, casting a polymer solution, and directly transferring the graphene patterns from the substrate to the surface of the target polymer film via a peeling-off method. The feature sizes of the graphene patterns on the final film can vary from a few micrometers (as low as 5 µm) to few millimeters range.

Electrical Differentiation of Mesenchymal Stem Cells into Schwann-Cell-Like Phenotypes Using Inkjet-Printed Graphene Circuits.

Graphene-based materials (GBMs) have displayed tremendous promise for use as neurointerfacial substrates as they enable favorable adhesion, growth, proliferation, spreading, and migration of immobilized cells. This study reports the first case of the differentiation of mesenchymal stem cells (MSCs) into Schwann cell (SC)-like phenotypes through the application of electrical stimuli from a graphene-based electrode. Electrical differentiation of MSCs into SC-like phenotypes is carried out on a flexible, inkjet-printed graphene interdigitated electrode (IDE) circuit that is made highly conductive (sheet resistance < 1 kΩ/sq) via a postprint pulse-laser annealing process.