Hydrodynamic interactions in quasi-2D creeping flow

Glycine, the simplest amino acid, has three polymorphs, namely, α, β, and γ. Under ambient conditions, α- and γ-glycine remain stable, whereas metastable β-glycine crystals gradually transform into α and/or γ forms. Notably,β- and γ- glycine exhibit unique piezoelectric response due to their non-centrosymmetric space groups. Previous studies have employed various methods to obtain the metastable β- or γ-glycine polymorphs, including quasi-double emulsions, templating techniques, and the application of electric fields, etc. Electrowetting (EW) is a versatile tool to switch the wettability of substrates and manipulate droplets. Few reports have studied the evaporation of water droplets or colloidal solution with electrowetting. Here, we work on the evaporative crystallization of sessile droplets of aqueous glycine solution, aiming to control the polymorphs and morphology of glycine crystals through electrowetting.