Modelling of the production of microwells

A new method for the production of microwells in polymers by solvent drops is presently under experimental and, by means of simulation, theoretical study. A small drop of toluene is placed on a plate of polystyrene. After evaporation a microwell is left as a mask for microlens production or to perform processes such as crystallization or chemical reactions. A mathematical model has been developed in order to understand the elementary effects in the system: (i) growth of the drop on the substrate, (ii) evaporation process of the solvent, (iii) dissolving of the substrate, (iv) flow rate in the evaporating drop caused by the pinning effect, including the vertical velocity profile, (v) increase of the concentration of dissolved material followed by precipitation. In the modelling and simulation process, it could be shown that the method of drop production has significant influence on the shape of the microwells