How droplets wobble on a vibrating surface can affect everything from the sharpness of pictures produced by inkjet printers to the flow of fluid through tiny channels etched into “lab-on-a-chip” devices used to perform medical tests or analyze polluted water. And oh, can they wobble. When standing still, droplets are typically drawn into a hemispherical dome due to surface tension of the fluid. But when researchers placed water droplets atop a glass slide under a microscope and shook them at various frequencies, the oscillating globules contorted into a variety of unusual, even unexpected shapes—from simple, gumdroplike blobs to triangles and five-pointed stars. Distortions in the paths of light traveling through the wobbling droplets (seen in video) enabled the researchers to map the shapes in 3D. In experiments that shook droplets at frequencies between 30 at 1100 Hertz (cycles per second), the team chronicled more than 30 different shapes , the researchers report online this week in Physical Review E. Inkjet printers aside, the results could lead to techniques that can use vibration to clear droplets off of a surface—a big problem in the microgravity of space, where droplets of condensed water vapor accumulate on heat exchangers but don’t drip away, dramatically reducing the devices’ overall efficiency.