Investigation of liquid droplet and liposome spreading on smooth and patterned substrates
Date of Issue2012
School of Mechanical and Aerospace Engineering
Robotics Research Centre
In this project, the spreading of liquid droplets and giant liposomes is investigated experimentally and numerically within the scope of continuum physics. Five liquids of different properties in their surface tension and viscosity are used, including deionized (DI) water, SDS (at the critical micelle concentration (CMC)), SDS (10% CMC), glycerol, and water-glycerol mixture (volume ratio 1:1). Liposomes are prepared from DOPC and the mixture of DOPA and DOPC (1:9). Isotropically patterned substrates and anisotropically patterned substrates are prepared to study the effect of surface patterns on spreading. The substrates for droplet spreading are fabricated on shape memory polymer through wrinkling, while those for liposome spreading are on silicon wafers by photolithography and dry etching. The wetting and spreading of liquid droplets and giant liposomes is characterized by the equilibrium contact angles, the equilibrium droplet/liposome dimensions, the dynamic change of contact angles, and the dynamic evolution of droplet/liposome dimensions.