For the radio, ask a HAM. I'm sure they can workshop something out of nothing and turn a clothes line in to a global command center... anyway yes, the size of long distance antennae will prohibit having them internal. One could include an SDR module but why not make it an add-on?
Since you only need a very small amount of current, something like a small compressed air canister could then presumably store many months worth of power. It would need to activate the air source for recharging only sporadically. This could be done using physical input from the operator and an NC-type valve in order to sidestep the flat-start problem, with a parallel option for electronic actuation.
Perhaps steampunk social networking would be a better market. One imagines darkly clad figures sneaking around urban environments clandestinely sneaking power top-ups from from random vehicle tyres...
i don't think it matters whether the efficiency is 100% or 1%; as it happens, i just pumped up my bike tire from dead flat earlier tonight, and i did on the order of 2 kilojoules of work with a hand pump to do that. 1% of that would be 20 joules, which would be 20000 seconds of full-speed 1-milliwatt zorzpad usage
and conceivably the pneumatic storage option could help to solve the problem of 'where do you store those joules until you're ready to use them?' this is a problem at the electrical level because batteries and electrolytic capacitors are not long-lived, and non-electrolytic capacitors max out at about 1 microfarad for ferroelectric mlccs. 10 volts at a microfarad is 50 microjoules, so storing an entire joule in long-lived capacitors would require about 20000 capacitors
but you still have the problem of how to convert the pneumatically stored energy into electrical energy at milliwatt rates (plus or minus a few microjoules, anyway) with decades of mtbf
if you're willing to require manual labor to pump up the palmtop with energy, though, a pullstring can store the energy in a steel spring, which can easily hold several joules and parcel them out at milliwatt rates to an electromechanical generator, with efficiencies in the neighborhood of 90% if you care about that. maybe you could even make it reliable, but it isn't obvious how. (grossly overspecced gears on bronze oilite bushings, maybe, driving a grossly overspecced generator?) a single heavy pull on a bowstring routinely stores around 100 joules, so i think a pullstring could be competitive
a manually powered computer like this could harness more energy at night than the purely-solar-powered zorzpad can. in the daytime, though, the sun provides more energy than you can comfortably provide by hand. consider a 150×90 pocket-sized notebook; in full sunlight it's collecting 20 watts, the equivalent of that heavy bowstring pull every 5 seconds. if only 30% of the notebook is covered in solar panels and they're only 10% efficient, you're still collecting 600 milliwatts, the equivalent of that heavy bowstring pull every 2½ minutes
that all makes sense but i think if you're aiming for longevity then separating the active mechanical bits (mtbf low) from the electronic bits (mtbf high) is a good idea, just because physical effort in proximity to breakable things is likely to break them faster. this would be a case for not building in the pullstring and instead using an external pump. but you could have both, as well. supercaps are good for capturing fleeting charge but don't store for too long. they do store longer than regular caps, but they leak current over time. an air tank can be 'on board' with high longevity and low mtbf. the connections/seals the probable locus of problems.
yeah, i guess i don't really know how long-lived supercaps are. just as a rule of thumb i figure that they'll probably fail soon just because they're full of liquid, but that's not an infallible rule; maybe they're long-lived
a 10-farad supercap at 2.7 volts could hold 36 joules and would still fit in your pocket, so you could totally charge it up with a pullstring. https://www.digikey.com/en/products/detail/tecate-group/TPL-... is 10mm diameter, 31.5mm long, and it's rated for 1000 hours of life at 85°. the datasheet projects that at 25° it will last 10 years with ±30% capacitance change and no more than 2× increase in esr. 53 years is 465000 hours but maybe at a low temperature and low voltage it would last that long? maybe it'll be 32× increase in esr but not a problem?
On pneumatics, https://en.wikipedia.org/wiki/Compressed-air_energy_storage suggests 50-70% efficiency at utility scale, with China leading. https://www.csiro.au/en/research/technology-space/energy/Ene... suggests 65% with 75% assumed aspirationally feasible. https://www.resilience.org/stories/2018-05-18/ditch-the-batt... suggests 75-85% but is likely non-holistic. https://www.signal.it/en/products/case-history-pneumopower/ suggests a small-scale implementation has been successfully productized. Indicatively at <=7 bar pressure they achieved post-loss output of DC24V@12W with a ~300g device. Since only a fraction of this is required, it should be possible to drop to ~50g with some loss of efficiency. Tiny motors are inexpensive as numerous factories compete for business, but they can fail so a replaceable setup external to the body would be preferable.
Since you only need a very small amount of current, something like a small compressed air canister could then presumably store many months worth of power. It would need to activate the air source for recharging only sporadically. This could be done using physical input from the operator and an NC-type valve in order to sidestep the flat-start problem, with a parallel option for electronic actuation.
Perhaps steampunk social networking would be a better market. One imagines darkly clad figures sneaking around urban environments clandestinely sneaking power top-ups from from random vehicle tyres...