Print revolution

From the Nature article:
A pioneer in the use of 3D printing for research, Zollikofer started 20
years ago with a prototype that was even more expensive and required
toxic materials and solvents -- limitations that put off most
scientists. But now newer, cheaper technology is catching on. Just as
an inkjet printer sprays ink onto a page line by line, many modern
3D devices spray material -- usually plastic -- layer by layer onto a
surface, building up a shape. Others fuse solid layers out of a vat
of liquid or powdered plastic, often using ultraviolet or infrared
light.  Any complex shape can be printed, sometimes with the help of
temporary scaffolding that is later dissolved or chipped away. These
days, personal kits go for as little as , says Terry Wohlers,
a consultant and market analyst based in Fort Collins, Colorado --
although industrial systems cost an average of ,000. Last year, he
says, nearly 30,000 printers were sold worldwide, with academic
institutions buying one-third of those in the ,000-30,000 price
range.
Early adopters are using the technology to investigate complex
molecules, fashion custom lab tools, share rare artefacts and even
print cardiac tissue that beats like a heart. At palaeontology and
anthropology conferences, more and more people are carrying printouts
of their favourite fossils or bones. "Anyone who thinks of
themselves as an anthropologist needs the right computer graphics
and a 3D printer. Otherwise it's like being a geneticist without a sequencer,"
says Zollikofer.
The printouts are yielding insights that are not possible with more
conventional methods. Neanderthal neonate fossils, for example, are
extremely rare, so Zollikofer did not want to risk copying his fragile
specimen with the usual plaster-casting methods. With the printout,
however, Zollikofer could explore the logistics of Neanderthal
births.  Along with the neonate skull, he printed out an adult,
female Neanderthal pelvis and literally re-enacted a delivery. Some
researchers had speculated that Neanderthals' wide hips made labour
easier than it is for modern humans, but Zollikofer's experiment
showed that the bigger skulls of Neanderthal neonates counteracted
that advantage.  Like humans today, Neanderthals
had the biggest heads -- and brains -- possible at birth, giving them
a jump-start on development.
In his work, Zollikofer swaps back and forth between printed models and
virtual ones. The computer models are good for calculating volumes or
piecing together bone fragments -- researchers can position them in
space without gravity causing them to fall. But with the virtual
models, he says, "you lose the sensation of touch, and even a notion
of the size of the fossils". The physical models are far better for
seeing how pieces should fit together in the first place, he adds.