Bump and Roll is an interactive exhibit that demonstrates nanomaterial properties using an everyday object: a leaf of cabbage. The nanoscale structures on a cabbage leaf cause water to bead up and slide off its surface. Scientists are replicating these “superhydrophobic” properties with nanotechnology. Drip water onto a cabbage leaf, and change the angle of the surface to see how the droplets behave. Find out about the super-small bumps that make this surprising behavior possible. Cabbage leaves must be replaced every few days, and Bump and Roll’s water tank must be refilled occasionally.