The silent, lightweight aircraft doesn’t depend on fossil fuels or batteries.
A new MIT plane is propelled via ionic wind. Batteries in the fuselage (tan compartment in front of plane) supply voltage to electrodes (blue/white horizontal lines) strung along the length of the plane, generating a wind of ions that propels the plane forward.
Unlike turbine-powered planes, the aircraft does not depend on fossil fuels to fly. And unlike propeller-driven drones, the new design is completely silent.
“This is the first-ever sustained flight of a plane with no moving parts in the propulsion system,” says Steven Barrett, associate professor of aeronautics and astronautics at MIT. “This has potentially opened new and unexplored possibilities for aircraft which are quieter, mechanically simpler, and do not emit combustion emissions.”
He expects that in the near-term, such ion wind propulsion systems could be used to fly less noisy drones. Further out, he envisions ion propulsion paired with more conventional combustion systems to create more fuel-efficient, hybrid passenger planes and other large aircraft.
Barrett and his team at MIT have published their results today in the journal Nature.
Barrett says the inspiration for the team’s ion plane comes partly from the movie and television series, “Star Trek,” which he watched avidly as a kid. He was particularly drawn to the futuristic shuttlecrafts that effortlessly skimmed through the air, with seemingly no moving parts and hardly any noise or exhaust.
“This made me think, in the long-term future, planes shouldn’t have propellers and turbines,” Barrett says. “They should be more like the shuttles in ‘Star Trek,’ that have just a blue glow and silently glide.”
About nine years ago, Barrett started looking for ways to design a propulsion system for planes with no moving parts. He eventually came upon “ionic wind,” also known as electroaerodynamic thrust — a physical principle that was first identified in the 1920s and describes a wind, or thrust, that can be produced when a current is passed between a thin and a thick electrode. If enough voltage is applied, the air in between the electrodes can produce enough thrust to propel a small aircraft.
For years, electroaerodynamic thrust has mostly been a hobbyist’s project, and designs have for the most part been limited to small, desktop “lifters” tethered to large voltage supplies that create just enough wind for a small craft to hover briefly in the air. It was largely assumed that it would be impossible to produce enough ionic wind to propel a larger aircraft over a sustained flight.
The fuselage of the plane holds a stack of lithium-polymer batteries. Barrett’s ion plane team included members of Professor David Perreault’s Power Electronics Research Group in the Research Laboratory of Electronics, who designed a power supply that would convert the batteries’ output to a sufficiently high voltage to propel the plane. In this way, the batteries supply electricity at 40,000 volts to positively charge the wires via a lightweight power converter.
Once the wires are energized, they act to attract and strip away negatively charged electrons from the surrounding air molecules, like a giant magnet attracting iron filings. The air molecules that are left behind are newly ionized, and are in turn attracted to the negatively charged electrodes at the back of the plane.
As the newly formed cloud of ions flows toward the negatively charged wires, each ion collides millions of times with other air molecules, creating a thrust that propels the aircraft forward.
This research was supported, in part, by MIT Lincoln Laboratory Autonomous Systems Line, the Professor Amar G. Bose Research Grant, and the Singapore-MIT Alliance for Research and Technology (SMART). The work was also funded through the Charles Stark Draper and Leonardo career development chairs at MIT.