Scientists in China have demonstrated a wireless power transmission system that uses a ground-based microwave emitter to beam energy to an antenna array mounted on the aircraft’s underside. Importantly, they were able to do this while both the drone and charging system were in motion.

In tests, the car-mounted system kept fixed-wing drones in the air for up to 3.1 hours at an altitude of 15 metres (49 feet). The key challenge that the team overcame was maintaining alignment between the emitter and the drone during flight, wrote Song Liwei, the project’s leader.

  • sp3ctr4l@lemmy.dbzer0.com
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    8 days ago

    Holy shit.

    Getting the ability to remote charge things via microwave… that are moving?

    That’s been basically sci fi nonsense, at a practical level, for a long time.

    Anybody remember the Microwave Power stations in SimCity 2000?

    If you could actually get this tech working, it has an incredible number of potential applications.

    • SaveTheTuaHawk@lemmy.ca
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      8 days ago

      Uh…they actually got this tech working.

      Will the US get this tech working? Can’t get anything working after slashing all research and kicking 10,000 phds out of the country.

      Cletus and his Ram 1500 is not going to figure this out.

    • HiTekRedNek@lemmy.world
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      8 days ago

      We’ve known about the possibility of doing this for decades.

      The NRL did a practical test of it in 2022 iirc.

  • teft@piefed.social
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    9 days ago

    Neat but 3 hours of loitering is nothing for a fixed wing drone. We have drones that stay in flight for a month or more.

    • Mycatiskai@lemmy.ca
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      8 days ago

      I have a 6 year old electric car that takes 40ish minutes to charge, now BYD has batteries that will go from 10% to 70% in 5-10 mins.

      In a few years time these drones will be getting charged from a microwave stream of power from a solar array floating in the upper atmosphere.

      • jaxxed@lemmy.world
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        8 days ago

        The decreased chargng time comes with a massive increase in charging power. The equivalent in ths scenario is to massvely increase the microwave power - which would likely cook the drone.

      • Atomic@sh.itjust.works
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        8 days ago

        Yes but you are charging through a conductive cable. It’s not even remotely the same as charging something with microwaves.

        The power delivered decreases exponentially with distance. I’m sure you’ve heard the phrase “inverse square law”.

        Because you divide the effect and gain by 4pi(r^2) meaning your output is decreased by 75% every time you double the distance.

        You’re going to need ridiculously powerful hardware and an enormous amount of electricity to run it on any meaningful distance.

        • Pyrodexter@lemmy.world
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          8 days ago

          A concentrated, collimated beam doesn’t act like a point source. There’s of course some amount of scattering and absorption loss due to atmospheric particles, but other than that a fully collimated wireless energy transmission doesn’t lose intensity over distance. Kind of obvious, really, because “where would the energy go?”.

          • Atomic@sh.itjust.works
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            8 days ago

            We already have concentrated microwave beams. And they do suffer immense energy loss on longer distances.

            If you want to transfer energy via microwaves, your efficency will reach single digits real fast on any meaningful distance.

            You are right that the inverse square law doesn’t realistically apply with concentrated beams. But you still have energy loss. Lots of it.

            But don’t take my word for it. https://www.nature.com/articles/s41598-022-25251-w

            • Pyrodexter@lemmy.world
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              8 days ago

              Quickly glancing through the paper it doesn’t really seem to support your claim. They attribute their major losses to the parabolic reflector (meaning they don’t have very well concentrated microwave beams?), and say that developing higher efficiency focusing components is important work for the future. I’m kind of guessing that’s one thing the Chinese are doing.

              Still, I’m sure there are relevant losses even in properly focused microwave beams. How much that is, I have no clue, and didn’t see it addressed in the paper. Might have missed it - it was a very quick glance. :)

              • Atomic@sh.itjust.works
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                8 days ago

                I’ll be honest, I didn’t exactly proof read every word either.

                I think what they meant with parabolic reflector is the reciever. They mentioned they 3d printed a reciever to achieve recors breaking efficency (short range). It’s not so easy to gather and convert the microwaves into electric energy. And it’s probably not very easy to create a concentrated beam either.

                But that was my interpretation. I’m not going to pretend I understand everything about this. I could be wrong.

                I think the technology to have satellites charge drones in the sky is at least 50 years away.

      • SaveTheTuaHawk@lemmy.ca
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        8 days ago

        But the Trump Navy will use cannons to fire coal up to drones and Tesla sexbots will shovel the coal.

    • willington@lemmy.dbzer0.com
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      8 days ago

      The difference is likely size and expense.

      Now you don’t need a 100 million dollar Boeing 737 sized drone to loiter for 3 hours.

      Previously small and cheap drones could loiter for 40 mins on an internal battery. Now they can stay up for 3 hours. That can be useful.

      Of course these mobile wireless recharging stations will become military targets for the opposition. So the overall combat math isn’t obvious to me, but it’s not a tech I see as obviously useless.

      This could be a much more straightforwardly a win for civilian applications.

  • sircac@lemmy.world
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    8 days ago

    Many comments are about how impractical/useless is this technology TODAY considering easier alternatives… but I see research exploring recharging electric flight devices in flight, which sounds as cool as powerful to have flight devices with larger services and ranges

  • AItoothbrush@lemmy.zip
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    8 days ago

    I mean this is really cool but at the same time doesnt seem usefull? Apparently the peak of modern combat is chinese drones with small bombs and a plastic fiber-optic cable attached to them lol.

    • pressanykeynow@lemmy.world
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      8 days ago

      There are a lot of different drones being used. For example you can’t use fiber-optic for drones that target something 100km afar. Either way the problem with this device is probably the same as with other anti-air systems - it costs, takes time to produce and to train the operator much much much more than to make a drone.

      • mojofrododojo@lemmy.world
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        8 days ago

        totaly agree with your firs two points…

        re: training and operators - my take on it is this has all the hallmarks of a swarm setup constantly recharging a portion of it’s numbers… Ukraine has illustrated that AI shit’s coming quickly, even if llm’s and jensen huang are wildly out of touch.

    • surph_ninja@lemmy.world
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      7 days ago

      I’ve lost count of technologies during my lifetime that had initial skeptics of ‘seems cool, but who would use this?,’ and then that tech became ubiquitous or essential within a decade.

      Room-sized computers that required punch cards also seemed cool but mostly useless once.

  • axh@lemmy.world
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    8 days ago

    Sounds:

    • Pretty advanced
    • Pretty expensive
    • Quite useless (I mean it definitely has its uses, but I think you could find much cheaper and simpler solutions)
    • A_A@lemmy.world
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      8 days ago

      “… you could find much cheaper and simpler solutions…”

      Heat feelt thanks for your bold show of confidence in my technical capacities. Yet I have to disclose that I’m not exactly sure to be able to compete with a first world power like China.

    • sp3ctr4l@lemmy.dbzer0.com
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      8 days ago

      We don’t even have automated battery replacement working on the ground, while stationary.

      Building aircraft with a whole bunch of their body and mass that significantly changes, in flight, is extremely expensive and difficult.

      Its why the V22 Osprey is widely regarded as a death trap, why we stopped building swing wing F-14s.

      … Have you ever tried to uh, remove your car’s rear seats, while on the highway, at 60 mph, and then also installed new seats, from a neaby car travelling alongside you?

      Ok now do that with aircraft, at 15k feet, going 600 mph.

      Yeah I’m sure that’ll be about as efficient as Elon Musk’s approach to designing the Starship+HeavyBooster.

      • zaphod@sopuli.xyz
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        8 days ago

        Yeah I’m sure that’ll be about as efficient as Elon Musk’s approach to designing the Starship+HeavyBooster.

        Compared to microwave energy transmission which has even worse efficiency.

        Ok now do that with aircraft, at 15k feet, going 600 mph.

        This is about drones. At 5 km distance and close to mach 1 you can absolutely forget any microwave based charging systems.

  • 0_o7@lemmy.dbzer0.com
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    8 days ago

    I have no knowledge in this and it’s early, but what happens to birds in the medium in between the receiver and emitter?

    This can’t be good for them.

    • HiTekRedNek@lemmy.world
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      8 days ago

      Nothing. It’s non-ionizing radiation.

      Microwaves ovens work by using extreme amounts of energy concentrated into a very small area.

      Microwave beams for energy transmission are different.

      We’ve known this since at least 1996 when the first paper talking about it was published.

      https://www.sciencedirect.com/science/article/abs/pii/0038092X95000834

      The biggest obstacle for it is actually RFI.

      Edit to add, and here’s a NASA paper from the 1980s talking about it

      https://ntrs.nasa.gov/citations/19800010018

      • feddylemmy@lemmy.world
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        7 days ago

        I think it’s worth saying that while not ionizing, high power high gain RF can cause damage via burns. Not sure how much power/gain is used in this situation though. Staying away from unfamiliar transmitting antennas is in general a good thing.