The Liberal Gun Club Forum

The challenge is that air is largely made of uncharged molecules that don't respond to electric fields. But at sufficiently high voltages, it's possible to ionize the nitrogen and oxygen that make up our atmosphere, just as lightning does all the time. The electrons that are liberated speed away, collide with other molecules, and ionize some of them as well. If this takes place in an electric field, all those ions will start moving to the appropriate electrode. In the process, they'll collide with neutral molecules and push them along. The resulting bulk movement of atmospheric molecules is called an ionic wind.

Calculations done decades ago, however, suggested that it wasn't possible to generate a practical amount of thrust using an ionic wind. Given advances in batteries, electronics, and materials, however, a team from MIT decided the time may have come to revisit the issue.

Doing so requires navigating a large series of trade-offs. For example, the lower the electric field strength of an ionic wind drive, the more thrust you get for a given power. Of course, if you drop the field strength enough, nothing will get ionized in the first place. Since the thrust per unit area is small, a more extensive thruster system makes sense—other than the fact that it will add to the drag and slow the craft down.

Still, after playing around with different thruster designs, the researchers found that it should be possible to generate sufficient thrust to get something airborne: "This level of performance suggested that steady-level flight of a fixed-wing unmanned aircraft might be feasible but at the limit of what is technologically possible using current materials and power electronics technology."