Finite curved creases in infinite isometric sheets.

Geometric stress focusing, e.g., in a crumpled sheet, creates pointlike vertices that terminate in a characteristic local crescent shape.

Chiral motion in colloidal electrophoresis.

Asymmetrically charged, nonspherical colloidal particles in general perform complex rotations and oblique motions under an electric field. The interplay of electrostatic and hydrodynamic forces complicates the prediction of these motions. We demonstrate a method of calculating the body tensors that dictate translational and rotational velocity vectors arising from an external electric field.

Predicting tensorial electrophoretic effects in asymmetric colloids.

We formulate a numerical method for predicting the tensorial linear response of a rigid, asymmetrically charged body to an applied electric field. This prediction requires calculating the response of the fluid to the Stokes drag forces on the moving body and on the countercharges near its surface. To determine the fluid's motion, we represent both the body and the countercharges using many point sources of drag known as Stokeslets.