Evaporation evolution of volatile liquid droplets in nanoliter well array

It is well known that solute usually carries out non-uniform deposition when deposited from evaporating droplet. In this study, the evaporation behavior of volatile micro droplets with nanoliter volume has been modeled and experimented in detail to insight this phenomenon. The results showed that there are two phases (I: constant baseline region in first 50% of total time, II: constant contact-angle region in the later 50% of total time) existing during the whole evaporation of water droplets. Average volume rate of evaporation is - 1.66nl/s for initial baseline of 2.27mm during 2160seconds. Furthermore, the evaporation experiment performed in circular nanoliter wells of 65 μm high and diameters ranging from 240μm to 1270μm demonstrated that the moving speeds of thin water film during rupture ranged from 20μm/s to 25μm/s, circular wells of larger size carried out, higher initial broken percentage. This study will be beneficial to the design of microstuctures for uniform solute deposition from the evaporation of liquid droplets. © 2005 IEEE.