A finite-element numerical model is developed to study the evaporation of a sessile nanoliter droplet on a flat substrate in the isothermal and non-isothermal case. All equations are expressed in a Lagrangian framework, which provides accurate modeling of the free surface motion and the associated Laplace stresses. The evaporative flux at the free surface is defined as a function of the drop geometry and thermodynamic conditions. The boundary conditions at free surface are the mass and energy jump conditions. Results for fluid dynamics, evaporation time and evaporative flux are described for substrate temperature levels of 27°C (ambient), 82°C and 122°C. Comparisons with experiments are made, in terms of the evolution of volume, wetting angle and wetted radius.

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