Slip-enhanced electrokinetic energy conversion in nanofluidic channels

Area of Science:

• Nanofluidics
• Electrokinetics
• Energy Conversion

Background:

• Electrokinetic phenomena offer a route for converting hydrostatic energy into electrical power.
• Hydrodynamic slip at channel surfaces can significantly alter fluid behavior in nanofluidic systems.

Purpose of the Study:

• To theoretically investigate the impact of hydrodynamic slip on electrokinetic energy conversion efficiency in nanofluidic channels.
• To analyze how slip length affects fluidic and electrical impedance, and overall conversion efficiency.

Main Methods:

• Application of the Navier boundary condition to model slip for both pressure-driven and electro-osmotic flow.
• Theoretical analysis of fluid velocity, streaming conductance, and impedance under varying slip lengths.

Main Results:

• Hydrodynamic slip strongly enhances electrokinetic energy conversion efficiency as slip length increases.
• Decreased fluidic impedance and increased streaming conductance contribute to higher efficiency.
• A moderate slip length of 30 nm in a 10 nm channel could yield 40% efficiency, approaching 100% with diverging slip.

Conclusions:

• Hydrodynamic slip is a critical factor for optimizing electrokinetic energy conversion in nanofluidics.
• Nanofluidic devices with significant slip, such as those utilizing carbon nanotube filters, show promise for high efficiency and power densities.
• Further research into slip phenomena could unlock practical applications for hydrostatic energy harvesting.