Underwater Wireless Information Transmission Enabled by Asymmetric Electrical Double Layers

ABSTRACT Wireless communication underpins modern connectivity and intelligent technologies across terrestrial and aerial environments, yet information transmission in water remains constrained by the strong attenuation, dissipation and interference experienced by optical, electromagnetic and acoustic signals. Here we propose asymmetric electrical double layers (EDLs) as programmable iontronic interfaces for underwater wireless information transmission, with ion redistribution and transport serving as information‐bearing processes. Charge‐density asymmetry between coupled solid–liquid interfaces produces unequal interfacial ion distributions and, under nonequilibrium excitation, concentration gradients that can direct ionic transport and enable ionic–electronic signal conversion. In this framework, EDLs are recast from passive screening structures as active interfaces that couple nanoscale ion dynamics to macroscopic signal generation. We outline how such interfaces could integrate underwater sensing, communication and energy conversion, and identify the mechanistic and engineering challenges that must be resolved to establish their range, bandwidth, fidelity and robustness in realistic aquatic environments.