THE DRAGONS
When standing on all fours, a typical full-grown dragon is about 3 times as tall as a human. They are quadrupedal with opposable thumbs, with four legs and two or four wings, and can reasonably be expected to remain in the air for at least several hours at a time (and that's the low limit for sick or malnourished dragons). They are broken up into a slew of sub-species, all of which share the above traits.
Some dragon species can breathe fire, but no dragon sub-species has inherent fire resistance. There are a few other 'inherent' abilities like ice breath, a venomous tail stinger, breathing underwater, and silk-weaving. Also, some of them have 'superpowers' of sorts that are not normal for their sub-species, such as super-hot scales, mind-reading, future sight, or the ability to communicate with plants and accelerate their growth due to circumstances of birth or genetics.
They are social creatures, and their societal structures at the moment are largely made up of Medieval Monarchy-dominated kingdoms. By some fluke of convergent evolution, they ended up with emotions, thought patterns, and psychologies nearly identical to humans despite having started at the top of the food chain rather than the middle.
They do know that some humans exist on the planet with them, but in their minds, humans are prey creatures noteworthy for making little metal daggers and wood/stone dens for themselves. They are technologically and socially behind the dragons, and the dragons have absolutely no clue that other, crazy-advanced humans are hanging around up in orbit. The realization that there are humans up on a metal palace in the heavens who have unlocked the esoteric secrets of trapping and harnessing lightning, traversing sections of the sky where the air is thin enough to cause a dragon to suffocate, and giving traits from one creature to another is going to come as a big shock to the dragons.
THE HUMANS
The humans abandoned earth in favor of a space station in earth's orbit for a time due to an incoming extinction event, and the dragons evolved and took the humans' place in the grand scheme of things while they were gone. During this time, the general difficulties of space forced them to revert to an authoritarian government. They've begun to scout out the earth to see if it's habitable or not, and haven't revealed themselves to any dragons or humans on earth yet.
Human technology stagnated during their time in space due to resource-conservation measures, but still managed to reach near-futuristic levels. They have reliable spacecraft (that are sadly not capable of FTL travel), holographic projectors that can be paired with motion sensors for a 3D interface or used to cloak a ship from view, tiny chip-like implants that can monitor vitals and brain activity, several dozen 30-foot tall mecha similar in appearance to Fortnite's B.R.U.T.E.s that can outclass a typical dragon in raw strength, and experimental Directed Energy Weapons that are actually fairly practical as weapons if a tad unreliable. However, they still walk around, mainly use weapons that utilize bullets as ammo, and are reliant on hydroponic gardens for food and mining ice off the moon for water. They haven't changed much, aside from limited forays into genetic engineering; they have yet to figure out how to make entirely new DNA, but they can 'map' known DNA patterns from one organism onto another organism OF THE SAME SPECIES, which allows them to cure genetic disorders.
Note that the humans are capable of communicating with the dragons through a 'translation device', despite the fact that neither of them is capable of speaking the other's language, but as a general rule they don't bother communicating.
The humans have a pretty distinct technological advantage over the dragons, but the dragon's abilities might tip the power balance back in the dragon's favor, and the humans are aware of this. And this is added to by the fact that there is only a quarter as many humans up on the station as there are dragons down on the surface.
THE SITUATION
When the humans first sent down their scouts to assess Earth's status, they were pleasantly surprised to learn that their homeworld was habitable and some of their kind had survived, albeit in a primitive state. Unfortunately, the humans had been ousted from their top position in the game of life in favor of dragons, who have all the advantages of sentience and opposable thumbs paired with the fact that they are 20-foot, tall apex predators. In fact, the Dragons even hunted the humans who remained on earth for food or kept them as pets! So the humans decided not to descend back to earth en mass, thinking that a cautious approach was best.
The dragons quickly perked the human's interest. For one, they are, much like bees, able to fly despite the fact that conventional physics tells them that their wings wouldn't allow them to. Plus, they'd really like to figure out how to get some of the dragon's abilities (anyone in favor of getting Telepathy?).
Now, to get these abilities, they need to map dragon genes onto their own genome, and to figure out how to do that do that, they need to do some experimentation. And the human in charge concluded that the most efficient way of going about that is to abduct live dragons seemingly at random from the planet and subject them to horrifically inhumane medical experiments that often leave the dragons dismembered, traumatized, and/or dead. Some humans objected, but those who did were quickly and violently silenced.
But, naturally, the humans who objected weren't the only ones who didn't approve of this. The dragons, much to the shock of NO ONE EVER, wouldn't go quietly to this grisly fate. And that leaves my main question: What physical restraints would these near-futuristic humans use to keep their dragon test subjects under control? I'm asking for what materials they'd use, but also what shape they'd be and what features they might include in the restraints.
CONSIDERATIONS
The physical restraints in question need to fit a few criteria; please take these criteria into account in your answers.
- The restraints can't be slipped out of easily. If there is a way to slip out of or break the restraints that doesn't entail significant self-harm, the dragons are going to try it, and some of them are going to be successful. And that means a scared, stressed-out dragon running amok in their labs, breaking all sorts of expensive equipment and causing harm to others and possibly itself in its frantic search for a way out.
- The restraints aren't prohibitively resource-intensive. These humans aren't suffering from any completely crippling resource shortages, but they do not have infinite reserves of resources and are VERY aware of this. The restraints need to be able to do their job, but they also need to do so without requiring a ton of resources to produce and implement.
- The restraints need to not interfere too much with experimentation. The humans want to be able to run experiments on the dragons, and that means that the humans must be able to preform surgical procedures/injections on them and transport them to different rooms for testing purposes without undoing the restraints too much. Metal cages and crates simply won't work for this.
- The restraints shouldn't cause harm to the dragons. This is because they want to keep some degree of restraints on the dragons at all times, for identification/tracking purposes. The reasons stem more from practicality than from any concern for the dragon's safety; kind of hard to figure out how much of an effect a given drug is having on a dragon when it's bindings are tight enough to restrict blood flow, and you don't want your dragon test subjects choking to death because the collar is too tight. This does not mean the restraints have to be comfortable.
EDITS:
It's important to note that while humans have absolutely no compunctions about killing dragons during experimental procedures, they are a little bit more hesitant about killing them OUTSIDE of experimental procedures. Each dragon they abduct represents a risk of exposure, and they're not going to kill a dragon if they don't think they'll get some interesting info out of it beyond the autopsy.
By near-futuristic technology, I mean any technology that we could conceivably develop given 100 more years or so of technological progress.