Graphene neural electrode

Graphene, a single atomic sheet of sp2 carbon, offers high conductivity, mechanical strength, flexibility, optical transparency, and chemical inertness, making it attractive for neural contacts, especially where transparency is needed for simultaneous optical imaging or optogenetic stimulation through the electrode. Monolayer graphene has intrinsically low double-layer capacitance, so recording-grade electrodes use porous, crumpled, laser-induced, or multilayer and reduced-graphene-oxide forms that restore high surface area.

A distinctive frontier use is the graphene solution-gated field-effect transistor (gSGFET), which records with a transistor rather than a passive contact and, crucially, captures the full band down to DC, enabling measurement of infraslow signals and spreading depolarizations that AC-coupled electrodes miss. Transparency also supports combined electrical and optical interrogation at the same site.