Silent Drone with Ion Propulsion - Venture Capital Backed -  Scam ? - Page 1
Forum section: electronics / general

author: matthewpang
author_rank: Contributor
timestamp: April 12, 2022, 07:40:05 pm
content: I just stumbled across this company (https://www.undefinedtechnologies.com) that claims to make a drone that can fly (in earth's atmosphere) using ion propulsion.Here is a video of them at a trade expoHere are some videos of their "silent" test" flightAnd I'm fairly sure you can both hear and SEE the giant ruddy ducted fan in the middle (with it's thrust vectoring surfaces).I'm fairly sure it's similar toWhat am I missing here ? What is this thing ?

author: Gyro
author_rank: Super Contributor
timestamp: April 13, 2022, 08:37:37 am
content: They're commonly known as 'Lifters'. They generate thrust by producing a stream of ionised air. They are extremely inefficient - last time I looked, the highest payload anyone had achieved is a small mouse, I don't think anyone has ever created one capable of carrying its own untethered HV power supply, let alone a useful payload!I built a very simple one once to see if the 'magic' actually worked...https://www.eevblog.com/forum/dodgy-technology/ionic-lifters-has-anyone-else-around-here-build-one/You'll find a couple of other threads if you do a forum search for 'ionic lifter' or similar. Don't get dragged into the concept of 'asymmetrical capacitors'.EDIT: Looking at one of the videos, there does seem to be quite a large diameter ducted fan in black box in the centre. Maybe that's lifting the payload and they're using the four lifter panels to lift themselves and provide pitch control (mentioned). Lifters aren't quiet by the way, they tend to emit a loud hiss of corona discharge. The whole thing is probably quieter than ones with several small diameter irritating high pitched whining propellers though.

author: Stray Electron
author_rank: Super Contributor
timestamp: April 13, 2022, 12:54:18 pm
content: a stream of ionised air (driven by a fan!) <> ion propulsion!Ion propulsion generates extremely small amounts of thrust and uses massive amounts of electricity. But also use extremely small amounts of propellant so that makes them good for LONG duration space missions that need only limited maneuverability and that have large amounts of excess electrical power generated by solar or nuclear power.After they are placed in the proper orbit, the new StarLink satellites are maneuvered by Ion Propulsion engines using Krypton gas but the engines only generate something like 0.1 ounce of trust. IIRC the new Starlink satellites weigh something like 35 pounds so they can only accelerate at about a 0.0001 g rate. At the earth's surface, an object has to accelerate at 1g just to main it's vertical position i.e. to hover.With current technology an ion engine doesn't produce anywhere nearly enough thrust to lift itself in a 1 g environment, much less it's propellant stores OR the required power source.

author: Marco
author_rank: Super Contributor
timestamp: April 13, 2022, 04:45:21 pm
content: Lifters would be more accurately be said to use particle acceleration for propulsion, they accelerate neutral air molecules by colliding them with charged molecules emitted from a high electric field electrode and travelling to a low electric field electrode.It's mostly the acceleration of the neutral air providing the lift, the mean free path for the charged particles is negligible, so they'll just be colliding all the way down.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 13, 2022, 05:11:58 pm
content: There was a self-powered demonstration a few years ago, I forget what or where exactly.There was this from MIT:https://news.mit.edu/2018/first-ionic-wind-plane-no-moving-parts-1121I recall a press release saying flight durations of like 3-5 minutes, which is pretty impressive moreso for the power density of the battery, and HV converter, than for the lifter/propulsion itself. Which I think did have some optimization, but still wasn't too different from the traditional wire-and-sheet configuration? I want to say it was a hovering type, but maybe it was this one I'm remembering after all. Which I guess, given the efficiency of a plane, goes to show just how awful it is as a propulsion method?Tim