A mighty wind
When a current passes between two electrodes — one thinner than the other — it creates a wind in the air between. If enough voltage is applied, the resulting wind can produce a thrust without the help of motors or fuel. This phenomenon, called electrohydrodynamic thrust — or, more colloquially, “ionic wind” — was first identified in the 1960s. Since then, ionic wind has largely been limited to science-fair projects and basement experiments; hobbyists have posted hundreds of how-to videos on building “ionocrafts” — lightweight vehicles made of balsa wood, aluminum foil and wire — that lift off and hover with increased voltage.Despite this wealth of hobbyist information, there have been few rigorous studies of ionic wind as a viable propulsion system. Some researchers have theorized that ionic thrusters, if used as jet propulsion, would be extremely inefficient, requiring massive amounts of electricity to produce enough thrust to propel a...