The lattice Boltzmann method (LBM) has experienced tremendous advances and has been well accepted as a useful method to simulate various fluid behaviors. For computational microfluidics, LBM may present some advantages, including the physical representation of microscopic interactions, the uniform algorithm for multiphase flows, and the easiness in dealing with complex boundary. In addition, LBM-like algorithms have been developed to solve microfluidics-related processes and phenomena, such as heat transfer, electric/magnetic field, and diffusion. This article provides a practical overview of these LBM models and implementation details for external force, initial condition, and boundary condition. Moreover, recent LBM applications in various microfluidic situations have been reviewed, including microscopic gaseous flows, surface wettability and solid-liquid interfacial slip, multiphase flows in microchannels, electrokinetic flows, interface deformation in electric/magnetic field, flows through porous structures, and biological microflows. These simulations show some examples of the capability and efficiency of LBM in computational microfluidics.

The dynamics of the wetting and movement of a three-phase contact line confined between two superhydrophobic surfaces were studied using a mean-field free-energy lattice Boltzmann model. Principle features of superhydrophobic surfaces, such as trapped vapor/air between rough microstructures, high contact angles, reduced contact angle hysteresis, and low resistance to fluid flow, were all observed. Movement of the three-phase contact line over a well-patterned superhydrophobic surface displays a periodic stick-jump-slip behavior, while the dynamic contact angle changes accordingly from maximum to minimum. Two regimes were found for the flow velocity as a function of surface roughness and can be related directly to the balance between driving force and flow resistance. This work provides a better understanding of dynamic wetting and fluid flow behaviors over superhydrophobic surfaces and hence could be useful in related applications.

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