title: Elasticity of microscale volumes of viscoelastic soft matter by cavitation rheometry.
abstract: Measurement of the elastic modulus of soft, viscoelastic liquids with cavitation rheometry is demonstrated for specimens as small as 1μl by application of elasticity theory and experiments on semi-dilute polymer solutions. Cavitation rheometry is the extraction of the elastic modulus of a material, E, by measuring the pressure necessary to create a cavity within it [J. A. Zimberlin, N. Sanabria-DeLong, G. N. Tew, and A. J. Crosby, Soft Matter3, 763-767 (2007)]. This paper extends cavitation rheometry in three ways. First, we show that viscoelastic samples can be approximated with the neo-Hookean model provided that the time scale of the cavity formation is measured. Second, we extend the cavitation rheometry method to accommodate cases in which the sample size is no longer large relative to the cavity dimension. Finally, we implement cavitation rheometry to show that the theory accurately measures the elastic modulus of viscoelastic samples with volumes ranging from 4 ml to as low as 1μl.
authors.affiliation: Department of Chemical Engineering, University of Michigan , Ann Arbor, Michigan 48109, USA.
authors.forename: Leonid
authors.initials: L
authors.lastname: Pavlovsky
authors.affiliation: Department of Chemical Engineering, University of Michigan , Ann Arbor, Michigan 48109, USA.
authors.forename: Mahesh
authors.initials: M
authors.lastname: Ganesan
authors.affiliation: Department of Emergency Medicine, University of Michigan , Ann Arbor, Michigan 48109, USA.
authors.forename: John G
authors.initials: JG
authors.lastname: Younger
authors.affiliation: Department of Chemical Engineering, University of Michigan , Ann Arbor, Michigan 48109, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Solomon