The innovation here is using the liquid ammonia to dissolve the silver (it will dissolve other metals as well). Liquid ammonia is really nasty stuff, we're not talking about the 5% ammonia gas dissolved in water you can buy in the stores here, which is pretty benign by comparison. Sorry, can't look up the boiling point on wiki just now - SOPA/PIPA protest over there, but it's cold. It's not real available, being used in major methedrine precursor manufacture.
There have been a lot of advances in "printing" things over the past few years, and it's kind of hard to tell where it is leading. Nothing even in the same (few) order of magnitude in either performance or size compared to integrated circuits on silicon has happened yet, so it's more a case of the dancing bear at present - amazing that he can, but don't judge by ballerina standards, you're going to be disappointed.
The rep-rap guys have been in touch with me about designing for them a way to work in things other than low-melt plastic, for what it's worth, but they need a lot of education at this point about things like - "can I put 5 lbs of powdered metal into a vacuum system and get to vacuum in minutes?", to which the answer is - not on this planet (huge amount of adsorbed gas on square miles of surface area).
Some interesting things have been printed. You could probably make a fairly decent AM radio on a sheet of paper...but I can now buy one on a chip that's about 2mm on a side for under 10c - less than the cost of a conventionally printed sheet of paper.
So, while the concept is kinda cool - and oh btw, has been used for as long as I've been in the electronics biz (about late '60s) - there are some pieces missing to "make the nut". For now it's about as overhyped as nano tech.
In other words, "wow, we can do this...now if we could do that, and some other thing, and a couple other nebulous things that probably require new laws of physics, we'd really have something". Yeah, right. Anyone familiar with what happens with a chain of sub-1 probabilities multiplied together can see through that hype, I hope. Yet the press-release science rags, on-line and dead tree, continue to publish this sort of thing as though world changing tech is around the corner. It helps scientists get funding, so it's popular. But it's not tradeable information in general.
Remember, in silicon chips, it's not the boron or antimony or other dopant (this is what makes the P and N types for circuits) or the aluminum or copper conductors that cost - it's the original very pure, very perfect substrate, and in some cases the NRE (design). And silicon has been more or less worked over by the very best minds for a long time to get prices down (thanks guys, it made my solar panels cost less too). The same issues will arise with organic semiconductors, and printable stuff - it's not the ink, it's the paper!
Who knows, someone could come up with a killer app out of the blue here - but my bet would be that they still use the uber cheap silicon chips, perhaps connected by ink. Most people don't realize how cheap those are, being at the wrong end of the 1000%++ markup on such things...(Intel's cost for a pentium chip fabrication works out to a couple bucks)
I recently completed a design project for my own outfit. It was a super fine preamp for nuclear detectors, designed out of discrete components for various reasons. OK, the theory isn't a problem here - I pretty much whipped this out. Then a guy who works with me laid out a PCB for it in about an hour, using common CAD tools. Two days later, after emailing the design to Canada to be made up with photolith - I have working product sitting in my hand right now. Which is to say, competition will be kind of fierce for anything new - the existing stuff works pretty darn well if the humans using it are top notch (and of course, Joe and myself are - and we're not all that rare).
We now use major functionality as building blocks, almost like legos. The previous product design, a standardized radiation counter, took about 2 weeks - start to finish.
I did the hardware and software design, Joe did the PCB's and box design, all CAD/CAM. I wrote the opsys for the little chip in about an hour (it's a lot simpler than windows or linux, and I was able to use already written pieces and drivers out of my box of tricks from having done this before...). You get the idea - I'm not trying to boast here, most competent engineers in my field could do this, might take a little bit longer, but it's not "rocket surgery" after some point.
And maybe that's the point - the human talent is the limit here, not the fab technology, which is pretty much "there". For that limited run product, Joe just cranked up the CNC mill and carved the boxes out of billet 6061.
The 3-d printers *are* cool for processes that need a lot of iteration to get to the viable point. One major reason the Japanese killed us in consumer gear was just how slick a Japanese stereo was in fit and finish - they didn't mind the die fees to have custom made molds made for plastics, our manufacturers were still carving this stuff out of metal and wood by hand, and didn't catch the wave there - and even though most of the insides of the Japanese stuff were junk by comparison - the consumer (ADHD?) went "oooh, pretty" and bought the bling instead of the more solid American stuff...
For cases like that - getting a case to hold the guts but fit nicely in your hand and also be make-able cheap - the 3d printers rule, because that field of design really isn't as well developed as say, software engineering or electronic hardware design, so iteration is the norm - and those things take a few thousand bucks off each iteration.
But mostly they are a solution in search of a problem. And oh, in the '60s, when Sony first came out with those tiny cassette machines - the PCB's were silver traces painted on... they were quite a bear o repair, as at that time they had super cheap female labor and the mech designs were...ummm....clever isn't the right word...dense?
