title: Polyhedra formation and transient cone ejection of a resonant microdrop forced by an ac electric field.
abstract: New deformation or fission phenomena are reported for microdrops driven by an ac electric field at their resonant frequencies. The Maxwell forces that pull out the vertices from a drop can be enhanced when the ac frequency is comparable to both the drop resonant frequency and the inverse charge relaxation time of the diffuse layer. The selected polyhedra possess symmetries that ensure a global force balance of the Maxwell forces and a linear dimension consistent with a sphere whose nth harmonic (n is up to six in the observation) coincides with the applied ac frequency. At high voltages, the resonant focusing of charges by the vibration modes produces evenly distributed and transient Taylor cones that can eject charged nanodrops.
authors.affiliation: Center for Microfluidics and Medical Diagnostics, Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Siddharth
authors.initials: S
authors.lastname: Maheshwari
authors.forename: Hsueh-Chia
authors.initials: HC
authors.lastname: Chang
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D002627:Chemistry, Physical / Q000379:methods*; D004339:Drug Compounding; D004574:Electromagnetic Fields; D036103:Nanotechnology / Q000379:methods
chemical_list: D000097:Acetonitriles; C032159:acetonitrile