True "Liquid Diode": Check Valve@Janus Membrane to Achieve an Extremely High Reverse Breakthrough Pressure.

Area of Science:

• Materials Science
• Fluid Dynamics
• Biomimetic Engineering

Background:

• Janus membranes exhibit unidirectional permeability, enabling spontaneous liquid transport from hydrophobic to hydrophilic sides.
• Current Janus membranes have limited reverse breakthrough pressure (RBP), restricting their practical applications.
• The unidirectional liquid transport function is critical for applications requiring controlled fluid flow.

Purpose of the Study:

• To enhance the reverse breakthrough pressure (RBP) of Janus membranes.
• To develop a Janus membrane with a true unidirectional liquid flow capability, akin to a "liquid diode".
• To explore potential applications in clinical medicine and microfluidics.

Main Methods:

• Integration of a gravity-assisted check valve with a Janus membrane.
• Fabrication of the check valve@Janus membrane composite structure.
• Experimental measurement of breakthrough pressure in both forward and reverse directions.

Main Results:

• The check valve@Janus membrane demonstrated a breakthrough pressure near zero in the forward direction.
• A significantly enhanced RBP of up to 4 meters of water height was achieved.
• The integrated check valve effectively prevented backward liquid flow, ensuring perfect unidirectional transport.

Conclusions:

• The novel check valve@Janus membrane design overcomes the RBP limitations of traditional Janus membranes.
• This innovation creates a highly efficient "liquid diode" with robust unidirectional flow.
• The enhanced Janus membrane holds promise for advanced applications in microfluidics and clinical medicine.