https://www.engadget.com/2018/11/21/mit-ionic-wind-aircraft-flies/?yptr=yahoo

MIT researchers have successfully flown an ionic wind-powered
aircraft that doesn't use any moving parts. The 16-foot wide machine stays aloft
by charging wires with a high enough voltage (40,000V) that they strip
negatively-charged electrons from air molecules, which are promptly attracted to
negative electrodes at the back of the aircraft. The collisions from that
newly-formed ionic wind create the thrust needed to keep the vehicle airborne.

Thanks to Brad Kushner.