Hmm, thought this sent, but it seems to have gone lost.
Overall very good, to the best of my knowledge.
Fig 1x.51 -- should be Al2O3, Ta2O5?
I suppose supercaps could be broken out into a few types as well, including those weird hybrid-ion thingies. Or further into batteries and general electric charge-based energy storage media... haha, well, that figure would span multiple pages, no need to go that far.
Varactors -- curious, has anyone made a MEMS variable cap yet? That would be interesting, probably not competitive with varactors though? I digress.
Fig 1x.52 could have one more blob, "transmission lines" I suppose?
I think it's amusing you left Fig 1x.61 in units of frequency -- perhaps you'll twig more people about using them as varactors. Or get more curses from failed attempts at it... :^)
May be worth noting that the capacitance decrease with frequency of Fig
1x.65 is equivalent to the damping factor of the previous section. Anywhere you have one, you necessarily have the other and vice versa. :)
Microphonics -- film caps do this to some extent as well (electrostriction moreso than piezoelectricity). Don't know that they're as microphonic as acoustically noisy, but it should be reciprocal, right?
Probably the more common case is film caps buzzing at mains frequency, especially when there's a lot of distortion.
Think I would rephrase the last paragraph of 1x.3.9 as: "Anywhere there's an electric field between the plates of a capacitor, and a mechanical force deforming those plates, microphonic and resonant effects exist. They're generally negligible though, and only exaggerated in certain materials."
Although re-reading it, I guess it says that, it just didn't grok right the first time?
1x.3.10.A -- now, I have a thing about bypassing, more generally PDN (power distribution network), so temper this accordingly; but anyway. The rule of thumb (the utilization quoted here), is generally alright for 2-layer designs, but by "generally" I mean "succeeds more often than it fails". It's typically overkill for multilayer boards, unless you need stupendously low impedances (usually CPU/FPGA Vcore stuff).
I think a discussion about PDN analysis would be more fruitful; probably not right here, but it would be good material for a new [sub]section, say?
(Unless you're editing it as we speak, and I'm about to be preempted again by your writing! :-) )
D.-- Don't discount ceramic caps -- specifically, C0G. It seems C0G materials handle /much/ more electric field before breakdown, so they store much more energy despite the low kappa. (In magnetics, it's the opposite: low mu higher energy density.)
Take for example, a 47nF 630V C0G 1812 (4.5 x 3.2 x 1.9 mm) that stores as much energy (9.3mJ) as a 33uF 25V 6.3mm dia. (5.2 mm height) electrolytic chip/can!
Only downside (other than the probably inconveniently high voltages) is the price...
There's also poled (electret) capacitors, which are still pretty boutique as far as I know, but they're out there. TDK CeraLink for example. Temperature sensitive, although I see some rated for reflow temperature now, without needing to be re-poled? What's up with that? Hmmm...
E. -- Worth noting that self-healing causes a hyperbolic decrease in capacitance, as self-healing starts as spots, giving way to chunks, and eventually bigger and bigger parts of the capacitor becomes disconnected.
They're also apparently sensitive to corrosion, which means (I assume) oxygen or water diffusing into the roll, oxidizing the (very thin) metallization, eventually raising ESR to the point where the capacitance doesn't exist. (This takes years to decades, AFAIK. Some datasheets provide temperature-humidity limits.)
So for long life applications under tough conditions, heavier metallization (lower ESR?) or foil may be desirable?
1x.3.12 -- gimmicks, may be worth mentioning PCB can be used this way as well. Can be varied at assembly time by jumpering to nearby pads, or by trimming copper outright. FR-4 tempco is quite nasty of course, as JL is fond of noting.
Footnote 53, ahh, you already preempted my comment from the last section! (The relation between L, C and v and Zo.) :^)
Cheers! Tim