Hands up if you know me.
Hands up if you know I have a huge crush on the concept of power armour.
Mostly the same amount of hands up, then.
Introduced to us as a concept back in the very early 20th century, power armour is a scifi staple. It runs from the improbable and highly fantastic, through to the more feasible and realistic. In movies, the contrast is visible in The Edge Of Tomorrow (essentially primarily just harnesses that increase lifting power and reduce recoil) and Iron Man (incredibly advanced and packing more bleeding-edge technology than your average Cyberpunk novel).
It's great stuff. A combination of protecting one's own soldiery and also allowing them to carry and manage heavier weapons, it is surely the military hardware of the future. A singular part of war is the capacity of a soldier to carry their equipment, which again would be amplified by power armour - though the commensurate increase in logistics would probably counterbalance their usefulness to a point.
So, why don't we have squads of MJOLNIR-equipped Royal Marines stomping all over the place?
Quite simply, there's bits of the technology that holds us back. We need certain things, certain kinds of technology to be available and widely researched in order to construct true power armour. There's a lot of similar projects in development right now that are similar - just take a look here for some examples, notables include Cyberdyne's HAL-5 and the Honda ex-legs project. Most of them take on the visage of the exoskeletons that are prevalent in the near-future presented in The Edge Of Tomorrow, though are far less advanced than the equipment presented in the book it is based on by Hiroshi Sakurazaka, All You Need Is Kill. (The novel comes highly recommended, by the way. Track it down.)
I'm not a scientist or an engineer. So my opinion, as always, needs to be taken with a pinch of salt. With those cards on the table, what do I think needs to happen to let us get on the board in terms of power armour?
The two primary issues, in my eyes, are power source and control mechanism.
In order for such armour to be useful, it needs to be able to perform with high responsiveness for a short period of time, and with low responsiveness for a long period of time. Military life is often described humourously as "hurry up and wait". It takes less energy to just move from one place to another, to get rom Point A to Point B and carry some things on the way - but far more time is going to be spent doing that, than in the middle of a fracas, which would require a lot of energy.
The idea of a small generator being attached to a fighting suit is less feasible than a suit being fitted with capacitors to be charged from an external source. So what is needed is capacitors, high capacity, quick to charge, and capable of variable output. There's a lot of study going on in this area. It's just a difficult balancing act - capacity and charging efficacy both come at a cost of weight and bulk, and finding the happy medium between them would be the solution. Where to put it on the suit, too, is a consideration - though just for balance purposes, I would think a distributed network of capacitors around the legs and hips.
The existence of the Formula E racing league - fully electrical cars tht can run at 140mph for an entire race and are recharged from glycerine - is proof that there's a lot that can be done with straight electrical power. If it can be monetised, it will be developed. Given that the new Renault electric car's battery is rented to the user rather than sold, let's face it - monetising is already happening.
The control mechanism? ...well that's a little harder.
If you want a suit of armour that can exert several tons of pressure at your command, you need to make sure it is going to go where you want to - that it isn't going to exert that pressure on you or on its own structure, and that there's going to be as little a delay as possible in transmission of command and execution of command.
Having it strapped to you, and reacting to pressure cues, is both simple and risky. The HULC system developed my Lockheed and Ekso Bionics uses footpad sensors that feed back into a microcomputer. This is great if all it is doing is moving at the same time as your legs and holding a backpack. A full body suit? Far more complicated.
Until we can get electronic control systems to the point where they can transfer motion commands from, say, a body suit to a limb possessing at least 8 actuators with accuracy - and allow for subtle variantions of motion, and ALSO allow for tactile and haptic feedback - well, Iron Man is beyond us. It's just not something we can do.
That's not a forever problem, in my opinion. That's a now problem. It just needs work.
In my National Novel Writing Month project, power armour features heavily. Even in the unspecified highly-futuristic time of the novel, it is a relatively new development. That is more down to efficiency of cost and training than anything else - but still, I hope it can demonstrate the complexity of such a system.
Keep dreaming, folks.