Recently I've read "To Sleep in a Sea of Stars" by Christopher Paolini, and rewatched Alien: Prometheus and Alien: Covenant. Two works of science fiction, one is the most hard science piece of media I've consumed since watching The Expanse (funnily enough they both have gray goo alien tech), the others being fairly solid additions to the Alien franchise, which often adheres to hard science, but fits more cleanly into an overall horror genre than anything else. I did also pick up Aliens: Fireteam Elite on Steam immediately after conceptualizing this essay, fully expecting to be disappointed by it. I found it to be decent, especially at a 60% discount.
Anyway, in To Sleep in a Sea of Stars (herafter referred to as "To Sleep"(Paolini does this as well)) there is a somewhat brief mention of Ablative Armor being used by the military (though this isn't seen in the book itself). Ablative armor is armor that can detect incoming projectiles and utilizes a blast of energy to block the projectile. This is normally concieved as an explosive device. In "The Universe" (a ttrpg by TowerRavens) they have a mix of ablative armor and a force field which projects force for moments at a time to block or hinder projectiles and movement. In general ablative/force armor/shields are futuristic peices of technology, one being more futuristic than the others.
I have always had a drive or compulsion to solve problems/do things better than the folks on TV. A particularly notable instance of it being a project friends of mine worked on about plague doctors in an alternate history. Their characters existed in and around the idea of necromancy and how its a metaphor for various personal issues the characters had (grief, naivety, hubris, etc.) and I insisted that I was special and could figure out a way to do necromancy without creating an abomination (This is also a driving force behind the very next miniessay about making philospher's stones). While watching movies in the Alien franchise I'm subconsciously and consciously analyzing it for procedures and technology to develop specifically to counter xenomorphs.
For the most part the Alien franchise does a decent job of making the xenomorphs killable, but reasonably hard to do so(sans the Alien 3 lead thing. that was ridiculous). Guns will take chunks out, fire will burn, blades will cut okish(exoskeleton is cut resistant), and they can be crushed. Overall procedure is very solid! For most of the franchise things go to pot when proper safety procedure is neglected, ignored, or violated (Alien Resurrection does a kinda Jurassic Park thing, where arguably the law of nature has been violated). So theres not too much to change, other than overall dessemination of xenomorph life cycle information.
However, like in Aliens: Fireteam Elite, people will need to fight them from time to time, and specialized gear is good or needed for effective xenomorph counteraction. The pulse rifle is a solid choice, automatic fire and an underbarrel grenade launcher/shotgun being as effective as any weapon against xenomorphs. The issue arises with the xenomorph superreactive acid blood (more effective than Fluoroantimonic acid(can melt glass and is stored in teflon), which is the strongest acid we know of, which has some interesting anatomical implications. Something that reactive probably(almost definitely) isn't effective as a circulatory substance. If I were designing xenomorphs I'd have a secondary system seperate from actual blood that pumps the acid throughout the body). In Alien the blood melts through several decks in a spaceship, and in Aliens it melts through people pretty darn quick. The only really effective armor is something that is resistant enough to it that you have time to take it off before it melts through the armor to you.
An early idea for a fix would be plated metal armor with electromagnet fasteners. Allowing for the plate to start melting before being unstuck and discarded, relatively easily replaced. With a high tech production you could have the armor automatically detect melting, and have the plates themselves be magnetized, allowing the armor to automatically repel/eject melting metal plates. This however has the hassle of keeping the armor charged, manually replacing the plates, and heat produced by the electromagnets. Theres something to be said about mechanical clamps engaging/disengaging, but I feel like that starts getting more and more finicky to implement, easy to fumble in a combat situation. Ablative armor and magnetically repelled plate armor also have the issue of flinging burning acid away from the body in somewhat violent ways. The magnetic plates are probably configurable to mitigate this, but theres also chunks of metal flying around. In zero or low gravity environments this would send the plates flying. Ablative armor has the chance to a) blow up and cause damage that way or b) turn the acid into a particulate cloud that is probably not good to float/walk through or breathe.
My solution (which I came up with prior to the magenetized plate armor) is cattail armor. cattails are somewhat well known because when bitten the seed fluff rapidly expands, filling a mouth and getting everywhere. Artificially developed and fabricated, it could effectively be used to counteract acid blood, expanding slightly faster than the blood can melt, but not flying off everywhere either. The fluff would be under a hard skin, which could be reasonably effective armor on it's own. I would estimate the strength of the material to be around that of paper armor, which has been estimated to be around the level of steel when reproduced. Paper armor is also done in a scale style, which allows for relatively easy manual restoration of activated scales. It really just needs to be strong enough to withstand the force of the piston-like innermouth of the xenomorph which has punched through rusty metal, glass, and bone with relative ease.
Having said all this, I'm somewhat disappointed that no one has come up with something like it to resist alien acid. Fireteam Elite is supposed to take place about 80 years after the Alien movies, and the weapons and armor are pretty standard to the movie era, hence the anticipated disappointment I mentioned earlier. The Alien franchise is all about the titular aliens, and focuses most of their development on their abilities, history, and behavior. Which is cool! To be fair, we don't see any sort of military intervention with xenomorph activity except in Aliens, and thats the first time any soldier has encountered them. Space truckers, colonists, and survey teams are not equipped to deal with xenomorphs in any way, shape, or form.
Fullmetal Alchemist is some of the best manga has to offer. It has a rich story, with elements that flow in and around eachother in sensible ways, a magic system that makes sense and is central to the plot without falling into the anime-style concentric limit-breaks and simply "being better at magic than everyone automatically". The characters feel real and the magic-science makes sense. It makes enough sense for me to get bothered by a way of creating philospher's stones that is ethically fine relative to the primary way it is done in the manga/anime.
Philospher's stones are made from the souls of human beings, killing them in the process. A single stone demands many souls, and theres some sense that the souls within are still aware of their existence, adding to the misery of philosopher's stone creation and utilization. Each stone is different too, some are red spheres, some are chunks of crystal, some are like mercury with strong cohesion. They're made with alchemy, spirit alchemy specifically, which is against the law. There was some slight limit-breaking late in the series, with using one's own soul to get more out of material alchemy than there was, but it doesn't break realistic human abilities, since it's such a high cost.
In the series as well, its shown that animals have souls too. What with the creation of chimeras, Barry the Chopper's body with the soul of some animal in it, and souls in suits of armor. When the dwarf in the flask destroys Xerxes it kills all living things, granting itself and Hohenheim immortality and a body made of philospher's stone material.
Here's where my idea comes in. Even if animals have a tenth worth of human soul, it is still more ethical, effective, and legal to turn a farm into a stone production facility. I concieved of an industrial chicken farm. At the top the chickens are hatched and raised. Beneath that is a circular room with the necessary transmutation circle carved into the floor (for OSHA compliance the circle would have a sturdy fence around it and a lock-out tag-out system that makes the circle unusable without a carved brick or somesuch). Chickens ready for slaughter would be gathered in the transmutation circle, and then converted to a philosopher's stone, killing all the chickens and creating at least a partial stone. This could be repeated over and over, likely creating stones that look to be some sort of sedimentary rock. The chicken carcasses are then processed normally (plucked, gutted, deboned, potentially rotisseried) and sold. The stones could be sold as well, potentially as a poultry product.
I imagine that it would be a lot better recieved than human-based philospher stones. Though people would protest it just as much as the current modern methods of killing chickens. To be fair, the chicken souls retain an amount of awareness in stone form, and I cannot imagine it is a pleasant existence.