Taming Lightning: Scientists Control Electric Sparks with Ultrasound

Electric sparks are widely used in the modern world: for welding, powering electronics, destroying microbes, and igniting fuel in some car engines. However, until now, controlling them in open space has been extremely difficult. Sparks tend to branch out chaotically and gravitate toward the nearest metal objects.

New research reveals a way to transport electricity through the air using ultrasonic waves. The level of control over electric sparks achieved by scientists allows them to direct the discharge around obstacles or to specific points, even in non-conductive materials.

Dr. Asier Marzo from the Public University of Navarre, the lead researcher on the project, says: "We observed this phenomenon more than a year ago. Then it took us months to learn how to control it, and even more time to find an explanation."

The mechanism for controlling sparks is based on the fact that they heat the air, which expands and reduces its density. This hot air is then directed by ultrasonic waves into areas with higher sound intensity. Subsequent sparks follow these areas of lighter air due to its lower breakdown voltage.

Professor Ari Salmi from the University of Helsinki comments: "Precise control of sparks allows them to be used in a wide range of applications, such as atmospheric science, biological procedures, and selective powering of electrical circuits."

Previously, sparks could only be directed with laser discharges, informally called "electrolasers." This method required the use of dangerous lasers and precise synchronization between the laser and the electrical discharge. The newly developed method uses ultrasound instead of lasers and is safe for the eyes and skin. The equipment is compact, affordable, and can operate continuously.

Josu Irisarri, the first author of the publication from the Public University of Navarre, shares his enthusiasm: "I am thrilled by the possibility of using very weak sparks to create controlled tactile stimuli in the hand. Perhaps we will create the first contactless Braille system."

The possibility of precise control of electrical discharges opens up new perspectives for innovation and technological progress. Researchers continue to explore the potential applications of this technology, which could change our interaction with electricity in everyday life.