The core difference between liquid gating technology and traditional membrane technology is that the transported fluid only contacts the gating liquid as it passes through the pores, without contacting the solid membrane material itself. In liquid gating technology, traditional scientific issues that occur at the solid/gas or solid/liquid interfaces are transformed into issues between solid/liquid/gas or solid/liquid/liquid interfaces. The introduction of liquid endows liquid gating membranes with excellent anti-fouling properties, energy efficiency, and design flexibility to meet different functional requirements. Additionally, since different types of transported fluids require different pressures to break through the gas/liquid or liquid/liquid interface, each fluid has a specific transmembrane pressure threshold. This endows liquid gating composite membranes with the ability to selectively separate different types of fluids.

        (a) The liquid stably existing in micron/nano-scale pores can serve as a reversible, reconfigurable pressure-driven gating liquid. When the transported fluid passes through the system, an interface is formed between the transported fluid and the gating liquid; (b)(c) Under certain pressure, the transported fluid deforms the gas/liquid or liquid/liquid interface and passes through the liquid gating composite membrane. The minimum pressure required for this process is the transmembrane pressure threshold (P_threshold). When the pressure of the transported fluid (ΔP) is less than P_threshold, the liquid fills the closed pores under capillary action; conversely, the liquid gate opens, allowing the transported fluid to flow through the pores, forming a functional liquid lining with a stable gas/liquid or liquid/liquid interface within the pores.