Atomic-scale ion transistor with ultrahigh diffusivity

Biological ion channels rapidly and selectively gate ion transport through atomic-scale filters to maintain vital life functions. We report an atomic-scale ion transistor exhibiting ultrafast and highly selective ion transport controlled by electrical gating in graphene channels around 3 angstroms in height, made from a single flake of reduced graphene oxide. The ion diffusion coefficient reaches two orders of magnitude higher than the coefficient in bulk water. Atomic-scale ion transport shows a threshold behavior due to the critical energy barrier for hydrated ion insertion. Our in situ optical measurements suggest that ultrafast ion transport likely originates from highly dense packing of ions and their concerted movement inside the graphene channels.

Automated summary

A new atomic-scale ion transistor has been developed using graphene channels around 3 angstroms in height controlled by electrical gating. The ultrafast and selective ion transport is achieved, with a diffusion coefficient reaching two orders of magnitude higher than in bulk water. In situ optical measurements suggest that the rapid ion transport is likely due to highly dense packing of ions and their concerted movement inside the graphene channels.