Dalhousie-AARMS AAMP Seminar: Andrea Bertozzi (UCLA)

Title:  Energy Minimizing Surface Tension Configurations for Microparticles

Abstract: An important area of microfluidics is the creation and manipulation of small droplets. This is commonly done using microchannels or electrowetting. Recently a new method is proposed to create templated droplets using amphiphilic microparticles. These particles are observed to hold nearly equal volumes of aqueous liquid when dispersed in an oil–water mixture. However a theory for this behavior is lacking. In this paper, we present a mathematical model based on minimizing the surface tension energy of a system of particles. By analyzing this model, we demonstrate that certain key properties of the particle guarantee the formation of small droplets within a volume range unique to the particle. We also look at statistical dynamics of pairwise exchange of fluids between particles for which the system can reach equilibrium.  We show examples of how such particles are useful for applications such as
biological assays and measurement of chemical secretions from single cells.