Electric sparks are used for welding, powering electronics, killing germs or for igniting the fuel in some car engines. Despite their usefulness, they are hard to control in open space—they split into chaotic branches that tend to go toward the closest metallic objects.

A recent study published in Science Advances uncovers a way of transporting electricity through air by ultrasonic waves. The level of control of the electric sparks allows guidance of the spark around obstacles, or guiding it to hit specific spots, even in non-conductive materials.

“We observed this phenomenon more than one year ago, then it took us months to control it, and even longer to find an explanation,” says Dr. Asier Marzo from the Public University of Navarre, lead researcher of the work.