Water-flow electric-gating effect on a van der Waals surface

Since the early 19th century, electric effects at fluid-solid interfaces have been widely studied, which primarily originate from migration of ions or their interactions with functional groups on solid surfaces. However, the intrinsic electric effect of moving water molecules on a pristine van der Waals surface has seldom been explored. Here, we find a water-flow electric-gating effect on graphene, WSe2, and MoS2 without dangling bonds or functional groups. It is an intrinsic electric effect, different from a traditional ion-reliant or functional group-dependent fluid electrokinetic effect. On the basis of this finding, we develop a water-flow gated transistor (WGT) capable of transducing flow signals down to 600 nanometers per second into electrical signals, achieving a voltage responsivity up to 1.53 × 104 volts per meter-second, about two orders of magnitude higher than existing hydroelectronic devices. The WGTs can serve as a basic unit of hydroelectronics, enabling efficient signal transduction and logical calculation.