On the other hand some basic armor, including over the face like a motorcycle helmet, will protect you against small charges.
How in the world could a railgun compete with chemical explosives? The energy density of batteries is nowhere even close to the energy density of chemical explosives; throw away the sci-fi railgun thing and put a small EFP on the UAV instead. That would be a thousand times more lethal with a fraction of the weight.
If you really want to use poison needles, then turn the UAV into a pincushion and crash it into people. If you're dead set on throwing needles, give it a compressed air blowgun. Small scale railguns make no sense.
It can selectively kill in a crowd. And no recoil, better accuracy during rapid fire.
Compressed air requires a canister of fluid that requires weight. With a rail gun, much of the weight is in the needles, which could be very thin indeed. When it's out of ammunition, it can do the suicide run perhaps. But the key is the unit doesn't need to carry all the energy required to dispense the projectiles on launch. Can feed off solar or power lines half way through its lot and therefore extend range or needle load.
In fact if you had a rechargeable system the drone could conceivably, albeit slowly, travel halfway around the globe, assuming it can extend its solar panels and float on the ocean.
I also expect they'll be totally silent and made of transparent material.
Add to that, the rails and the capacitor bank have mass, substantially more mass than the needles. The same force that sends a railgun projectile down the rails also tries to push the rails apart. The rails need to be strong enough to resist this force trying to separate them. You can't even let the rails flex, because if the rail loses electrical contact with the projectile then there's no current flow and therefore no force to push the projectile. For a railgun this small you can probably wrap the whole assembly in carbon fiber and call it a day, but there's no way any of this comes out weighing less than the needles themselves. Just one of the capacitors will weigh more than a bunch of needles.
An air canister weighs to much? A standard CO2 cartridge weighs about 50-100 grams and has ample capacity. A CO2 cartridge in an air pistol lasts for dozens of shots, that's plenty.
And silent and transparent? Now I think you might be trolling. Neither UAVs nor railguns are silent and only a few components in them could conceivably be made transparent.
Good troll so far, but I think this puts it over the top.
1. Needles do not have the aerodynamic properties necessary to be effectively fired.
2. Chemical explosives and kinetic payloads are far better in terms of energy and weight than railguns. You'd see electromagnetic launchers being used for nailguns if they were at all reasonable for the relatively low amounts of power involved, and they aren't, and it's for good engineering reasons.
3. Chemical agents often have shelf-life issues, particularly when they're stored like you're proposing.
4. Solar recharging is going to have significant weight costs and result in either low duty cycles (most of the time spent sitting waiting for more energy) or other significant performance tradeoffs.
5. Perching on a power line does not give you access to electrical energy, you need a voltage difference to recharge, plus line voltages are really unsuitable for batteries and electronics, so you'd need a large (and heavy) transformer to step things down anyways.
6. Everyone with the technical capability to develop nuclear-powered aircraft has already looked at the problems and risks involved and said "oh hell no". Furthermore, if you miniaturize these things so they can be deployed en masse, the battery size and long-term contamination risk go way down anyways.
Stop watching so much SciFi and come back to the real world.
It was routine what 80 years ago to gas civilians. The only reason it wasn’t employed on the battlefield was that it was as likely to kill your troops as the enemies.
Violating that ban is inevitable - as soon as one country adopts a ‘more discriminating’ method of killing and gains an edge, the rest will follow suit. They’ll sell it saying a drone would never accidentally kill a non combatant.
The naivety of suggesting the technology can’t be developed with the pace of change we’re witnessing is astounding. They certainly can make a micro railgun, probably already have secretly. And I doubt a micro drone needs much more current than a pacemaker provides, especially with an energy efficient SoC at the latest fab.
As for a "micro railgun", that's just pure nonsense. You might as well claim that the military has secretly developed time machines or warp drives. Come on.
You're in no position to make promises about anything.
You may say I'm a dreamer, But I'm not the only one.
It would have shock value if you did something half-assed with a drone swarm but then you should be very careful that your drones or deployment mechanisms aren't traceable back to you.