Electrorheological (ER) Fluid

Application of a high voltage across a slurry of cornstarch and corn oil reversibly increases the viscosity of the slurry.

ABOVE: OK, so the pictures of the electrodes did not turn out that well. But, the shadows of the electrodes on the blackboard are visible. At left are a pair of bare electrodes with no voltage applied; at right are the electrodes with the ER fluid suspended between them due to 2500 applied volts.