A 3D printing thought…
Some of the first 3D printers used a UV cured resin extruded by a inkjet printer head. Variants of this technology using the precision of the liquid extrusion and lasers are still in use today, allowing superfine detail.
I was thinking after reading the news about the breakthrough in graphene superconductors (first relevant google link):
about the form of the feedstock. The process used by the UCLA folk was to take graphite oxide and heat it with a laser, driving off the oxygen and causing it to link up into graphene. This, by the way, is a good place for anyone with a laser engraver to start looking at a new business–a supercap the size of a AA or AAA battery will carry enough juice to be useful for some intermittent work, like electric toothbrushes and the like. Another was an article on “printing” drugs. They both use somewhat simple setups to do chemical manipulation.
Anyway, Nanosolar uses a semiconductor solution called CIGS to literally print their cells on a regular roller press. Add a resin for the board, a copper solution of some sort for doing traces, and something for smaller capacitor dielectric and resistors. Printer head spits out the materials, sets them with the laser, and vua-la! Circuit board, with all discrete components(and probably a fair number of logic circuits) done, ready for the IC to be plugged in. Even better, since the setup is a 3D printer, large scale components like inductors can be make too, assuming you don’t also want to make your circuit board 3D, or integrated into another design.
I was thinking though you could probably expand this thought. Metallurgy is one place where 3D printing is lagging behind. A large number of the properties of metal aren’t just because of the chemistry, but also the physical structure, which is affected by the production process. A process like selective laser sintering is limited because it can’t forge the metal, so the item is weak, potentially even weaker than a cast part. This is not easily solved with a physical process, but perhaps if you were using iron and it’s alloying agents in a solution, the particular solution and it’s laydown could be used to cause an alignment similar to the physical action of working, allowing a more usable structure.
At the point we’re at, there are workarounds though. A small set of rollers can be made easily enough, and a computer controlled system could take a thin printed part and roll it out, cold rolling the material and then the stronger, more durable material would undergo a tertiary folding and assembly to make something like a toolbox. The challenge presented here though, is that a lot of things we use are far too durable to make using quick and dirty processes. The next revolution won’t be making 3D printers cheaper, but finding a way to print the way strong materials like metal need to be made for best results.