Shape-Directed Rotation of Homogeneous Micromotors Via Catalytic Self-Electrophoresis

Scientific Achievement

We showed how particle shape alone can induced and direct the motions of catalytic micromotors via chemically fueled electrokinetic flows.

Patterned disks of platinum exhibit different rotational motions in H2O2 solutions.

Significance and Impact

New insights into the mechanism of catalytic propulsion will enable the design of active colloidal components.

Research Details

• Nanofabricated particles with n-fold rotational symmetry rotate steadily about their axis with speed and direction specified by the type and extent of shape asymmetry.
• We provide evidence for self-electrophoretic propulsion, whereby anodic oxidation and cathodic reduction occur at different rates at different locations on the particle surface.
• We present a mathematical model that explains how particle shape impacts the electrocatalytic reactions to direct electrokinetic flows that drive particle motions.

Work Performed at Columbia University and Penn State University.