Salvinia-inspired architectures for enhancing interface stability and mass transfer in microchannels

Area of Science:

• Microfluidics and Interfacial Engineering
• Materials Science and Surface Chemistry

Background:

• Conventional microchannels face limitations in mass transfer efficiency due to wall diffusion or interface instability.
• Existing methods struggle to maintain stable interfaces, hindering efficient interphase transport in microfluidic applications.

Purpose of the Study:

• To design and develop novel composite microchannel architectures for enhanced mass transfer and interface stability.
• To investigate the application of nature-inspired surface modification for improving microfluidic performance.

Main Methods:

• Fabrication of composite architectures with spatially selective hydrophilic modification via in situ polydopamine (PDA) grafting.
• High-speed imaging to analyze interfacial morphology dynamics and failure behaviors.
• Cyclic pressure loading experiments to assess interfacial pinning and stability limits.
• Development of mass transfer models to quantify efficiency under various flow conditions.

Main Results:

• The PDA-modified architecture demonstrated enhanced interfacial pinning, increasing the stable operating pressure range by over 20%.
• The modified microchannels showed doubled tolerable disturbance frequency, indicating superior interface stability.
• Mass transfer models confirmed efficient gas-liquid transport and a >15% improvement in liquid-liquid extraction efficiency under pulsatile flow compared to static conditions.

Conclusions:

• The developed interfacial engineering strategy, combining structural design and wettability control, significantly enhances mass transfer and interface stability in microchannels.
• This nature-inspired approach offers a robust solution for efficient multiphase transport in microfluidics.
• The technology holds broad potential for applications in chemical separation, gas-liquid reactions, and advanced microfluidic devices.