What can we do with a piece of bare graphene? Maybe the thinnest and most sensitive flow sensor. The above image shows the contact electrification at the interface between monolayer graphene and blood. The charge-transfer current is modulated by the flow near graphene, thereby characteristic to the flow velocity. Our experiment shows that graphene flow sensors based on this mechanism is of orders-of-magnitude improved performance metrics comparing with existing technologies: single-atom thickness, sub-micrmeter/second sensitivity, and over six-month stability.
The paper was published in Nature Communications.