One of my all time favorite Mythbusters episodes was a test of “anti gravity” devices found on the Internet. One of them was a strange triangle with no moving parts and they were all laughing at yet another goofy Internet scam—and then it actually lifted off the table. Grant, Tory, and Kari just about soiled their pantaloons!
The device tested on Mythbusters does actually lift, though it is not anti gravity, it is an “Electrohydrodynamic” lifter. A high electric field creates a charged plasma field which bounces off air molecules, generating downward thrust. As Evan Ackerman notes, the idea has been around for a while, and there is even an intrepid mouse name Orville who flew in one circa 2003.
Last summer researchers at Berkeley report on a scaled down version of this concept that they call the Ionocraft . At 2 cm square and 30 mg, it’s tiny (the power supply is external, of course).
In fact, scaling down makes things work better. The thrust to weight ratio improves, and the lack of moving parts make fabrication easier and operation more reliable.
As Evan Ackerman points out, this is absolutely not a biomimetic or bio-inspired design . But this may have advantages over the heroic efforts to mimic bees and other small flyers. (I did mention “no moving parts”, didn’t I?)
OK, lift is one thing. Control is another thing entirely. Much of the paper is about the sensors and autonomous guidance systems. Tiny systems, and apparently capable of working in the vicinity of significant plasma generation.
The paper indicates that the thrust generated is designed to be controlled by algorithms similar to conventional quadcopters. (I.e., there are 4 controllable thrusters.) I have to say that the demo video does look all that controlled. But then again, the miracle is that the dog dances at all. In any case, they have ideas about how to stablize the flight.
- Evan Ackerman, Penny-Sized Ionocraft Flies With No Moving Parts, in IEEE Spectrrum – Robotics. 2019. https://spectrum.ieee.org/automaton/robotics/drones/pennysized-ionocraft-flies-with-no-moving-parts
- D. S. Drew, N. O. Lambert, C. B. Schindler, and K. S. J. Pister, Toward Controlled Flight of the Ionocraft: A Flying Microrobot Using Electrohydrodynamic Thrust With Onboard Sensing and No Moving Parts. IEEE Robotics and Automation Letters, 3 (4):2807-2813, 2018. https://ieeexplore.ieee.org/document/8373697