So firstly, how do we go about printing in 3D? The cheapest RepRap 3D printer currently retails at £749. This allows users to print with 2 types of plastic, acrylonitrile butadiene styrene (ABS), and Poly(lactic acid) (PLA). Users either download designs from repositories like Thingiverse, or create their own design in 3D software like SketchUp. Many different types of printing are possible, the RepRap using a technique called Fused Deposition Modelling (I think we'll stick with FDM). In FDM, filaments of the desired plastic are wrapped into coils (think 3D ink cartridges), and when required drawn into a nozzle. This nozzle is heated, so the plastic melts. A computer directs the nozzle in 3 dimensions, so the melted plastic is placed exactly where required. Once the plastic is out of the nozzle, it cools and hardens, to form part of the 3D object.
So you've got your printer, stocked up on filament, now what? Well some of the simpler chemistry designs available are for common lab gear like Buchner Funnels. However, if I wanted a plastic Buchner funnel that'll likely dissolve at the first sign of an organic solvent, forking out £749 for a 3D printer wouldn't be my first idea. £749 is enough to keep even
The simplest, genuinely useful piece of lab equipment I've seen (and I'd love to hear about others) is the DremelFuge (video in the first link), for the price of a drill, and a few grams of plastic (I make it about £60), you've got yourself a basic centrifuge capable of speeds up to 33,000rpm - which is getting into "ultracentrifuge" territory. Need a handy centrifuge for field work? Forgotten to balance your lab's centrifuge and written off a £1000 piece of kit? Suddenly the DremelFuge sounds pretty attractive. Whilst I'm not suggesting selling your bench-top centrifuges and heading down to B&Q, for labs on a budget, hackerspaces for examples, you're opening up avenues that wouldn't previously have been possible without serious funding.
But yes, most labs that need one already have a perfectly good centrifuge, and whilst it shows 3D printing can potentially save costs (especially when you've already taken the initial hit on the printer) its not shown it can truly innovate yet. What about your own personal pharmacy?
That's just what the Chronin group at the University of Glasgow have been doing. Using an adapted 3D printer, they've developed techniques for printing reaction vessels, with the chemicals already inside. By inserting electrodes, they were also able to produce an electrochemical cell. Next (and this is where 3D printing becomes really interesting), they found that the shape of the vessel determines the products formed. As proof of concept, they've used this to synthesise some novel heterocyclic molecules, with the printed reactor vessel an important part of the synthesis.
Finally, their pièce de résistance, is reaction vessels that play an active part in the reaction. By mixing a Pd/C catalyst into the plastic used to fabricate the reaction vessel, the vessel could be used to hydrogenate styrene to ethylbenzene in around 30 minutes at room temperature.
So where's this heading? Cronin's group envision a situation where you combine some biotechnology into this too, and create a one-piece home lab, where you give it some cells, it works out what diseases you're susceptible to, produces a drug to cure it, and all before you've even developed a symptom. We're not quite there yet, but that's something pretty awesome to aspire to.
Sticking with their catalytic vessels, they also suggested using it so patients can make their own drugs at home, from a common starting material. Imagine it like a Rubik's cube. You buy your starting material from the supermarket, and stick it in the top. Each block in the Rubik's cube is impregnated with a different catalyst, so by directing your starting material from square to square, you'd be able to transform it in different ways. I can imagine a situation where you look up a recipe for, say, Bupropion, with instructions like, "twist top of cube to the left, rest on it's right side, then leave in the microwave for 10 minutes".
Give it 10, maybe 15 years and if I was a pharmaceutical company, the DEA (it's not hard to think of some illicit applications, is it?), or, sadly, your friendly departmental glass-blower, this technology would be starting to worry me, because the possibilities for 3D printing really do seem to only be limited by human imagination.
For more on the work of the Cronin group, this BBC video is a nice introduction, the RSC have a decent article here and the groups paper is also available here (if you've got Nature Chemistry access - unbelievably my uni don't). For more on 3D printing, there's a nice article in Science magazine (again, pay-walls, sorry).
As usual, any comments or questions would be much appreciated. If you spot a mistake, or feel I've missed something, let me know. Anyone wondering where the second part of my Sports Drug Doping series has got to, it's coming, I'm still gathering material. There's a follow-up to my Petrol from Carbon Dioxide blog in the pipeline too-when I've found out how many cows are on the planet (all will become clear!).