It was just July 7 when we blogged about a 3-D printer creating a crescent wrench as strong as the original. That blog was accompanied by a short video showing the process from start to finish–one certain to entertain your class. But today’s Wall Street Journal (July 16-17,2011) has raised the 3-D printing bar potential way beyond plumbing tools. With the title, “How Close Are We to Printing New Organs?”, the Journal describes how a whole dummy kidney made of biocompatible materials 
and cells, was “printed” on stage at a TED talk a few months ago. With about 90% of patients needing a transplanted organ seeking a kidney, being able to create a “self-derived” kidney would save many lives and spare people the expense and pain of dialysis.
Such “printed” kidneys that would be able to work in the body (they are structural, but lack blood vessels) are still years away, but the rate of advance means the 1st autologous transplant may still happen this decade. Already, synthetic windpipes, grown with a patient’s own cells, are being transplanted. (The windpipe of the patient is scanned, molded from a porous medical plastic, and infused with cells from the patient in a bioreactor).
And the concrete in our blog title? Here is a 3-minute video of a concrete structure being built by a grander and rougher 3-D printer at a British university. The architect makes the design, after which the printer extrudes concrete from a nozzle to build up the object, layer by layer. Printed concrete products are proving to be stronger than the cast ones. They also have the advantage of a hollow interior through which a building’s wires and pipes can be run. And the ducts in the concrete parts look uncannily like blood vessels needed in the 3-D kidneys. Pretty exciting advances in OM technology!
Discussion questions:
1. Why is 3-D printing, which has been around for a decade, now becoming such an important tool?
2. Ask students to research the costs of 3-D printers.