So, I was thinking about spacesuits.
At the moment, there are two design options for spacesuits. One is the mostly-fabric design that astronauts actually use. It is very sophisticated, but it is still exhausting to work in, because the internal pressure tends to inflate to suit into a particular posture, and any movement has to overcome that force.
The other is the "lobster" type of suit (more familiar as a deep- sea suit). It consists of rigid sections articulated at various points. It's designed such that its internal volume stays the same in all positions, which means that air pressure does not resist movement at all. It's said to be much less tiring to work in. However, it has some limitations imposed by the nature of the joints (which must all be airtight, of course). As a result, some movements must be made in the right order (eg, first move the shoulder, then the elbow; not the other way around) or the suit "jams". It's also difficult to maintain good seals at all the joints.
A third type of suit has been proposed in the past, consisting of nothing more than a body-hugging mesh (except for the head, which is sealed into a regular helmet). Skin can cope quite well with vacuum as long as it is confined by a fairly fine mesh. The mesh has to provide a supporting force of only a very few PSI. These "stocking suits" would be great, except that they don't work. The reason they don't work is that you can't make a mesh suit which presses evenly on all areas of skin, in all body positions.
So, here are two possible ways to implement the mesh spacesuit.
Way 1: glue-on mesh. The astronaut dons what is basically a mesh leotard, and is then liberally sprayed with a flexible glue that bonds the mesh to the skin. Once glued in place, the mesh will serve its compressive function regardless of movements. The mesh suit can be removed by spraying with a suitable agent to break the mesh/skin bond. There are plenty of biological-based glues (for instance, the ones that mussels use to glue their attachment threads to rocks) that will serve admirably and can be dissolved by fairly benign enzyme solutions.
Way 2: thermally-responsive mesh. For this, we need the mesh to be made of a bimetallic thread, oriented in the right way. If he/she moves in such a way as to create a gap between body and mesh, the cooling of the body-side of the mesh filaments will cause them to bend, until they once again contact the body. If the filaments of the mesh are fine enough, this response could easily keep pace with movements.
(*And yes, fishnet would be much too coarse and bits of you would bulge out between the fibres.)-- MaxwellBuchanan, Aug 05 2019 A song has been written about this idea ... https://www.youtube...watch?v=zPwMdZOlPo8 [normzone, Aug 08 2019] Unfortunately, skin is elastic, so "glue-on" won't be particularly good if you want to move & breathe & so forth. Thermal could work; I'm not sure it would respond fast enough (or physically change enough) to the small changes in temperature. Way 3 is to use an "active" tension suit: pressure sensors against the skin instruct nitinol / piezo / actuator / something to maintain a particular pressure by continuously adjusting the tension. Complications (in all options) come in places of "negative curvature", such as armpits, groin, front-of-ankle. A small "active" bladder (specifically shaped to fit) in those places could keep pressure while allowing movement. And of course, breathing needs to be accommodated; unless a 2- way-pumped air supply both fills AND empties the lungs, without the need for chest/diaphragm movement. (Yes, I have put quite a bit of thought in to tension suit design before...)-- neutrinos_shadow, Aug 05 2019 //"glue-on" won't be particularly good if you want to move & breathe & so forth// Depends on the stretchiness of the fibres, at least for moving and breathing. If you want to get up to so forth, it's probably safer for everyone if you do it inside the space ship.-- MaxwellBuchanan, Aug 05 2019 <Contemplates mental image of bits of [MB] bulging out between the fibres/>
<Considers mental image of [MB]'s siblings in similar circumstances />
<Plaintive whimpering/>-- 8th of 7, Aug 05 2019 Interesting - so why wouldn't a neoprene scuba wetsuit (with water providing a thin layer between the body and the suit, and filling in any voids) together with a proper helmet work as a spacesuit?-- hippo, Aug 06 2019 Because you'd end up with a human-shaped balloon - the suit would resist any movement that reduced its volume, just as the current suits do.-- MaxwellBuchanan, Aug 06 2019 Yes, so the astronaut might die from being unable to exhale-- hippo, Aug 06 2019 //bits of you would bulge out between the fibres.
<Frankie Howard>Oh no missus</FH>
How often do astronauts need to go outside? Seems a damn cheek when NASA spent oodles of tax payers cash making a nice capsule for them.-- not_morrison_rm, Aug 06 2019 ^Or accompanying regolith sampling stilettos? for that real 'time warp' capability.-- wjt, Aug 07 2019 random, halfbakery