The approach, volumetric bioprinting, forms tissue by projecting a laser down a spinning tube containing hydrogel full of stem cells. You can shape the resulting tissue simply by focusing the laser's energy on specific locations to solidify them, creating a useful 3D shape within seconds. After that, it's a matter of introducing endothelial cells to add vessels to the tissue.

The resulting tissues are currently just a few inches across. That's still enough to be "clinically useful," EPFL said, and has already been used to print heart-like valves, a complex femur part and a meniscus. It can create interlocking structures, too.

While this definitely isn't ready for real-world use, the applications are fairly self-evident. EPFL imagines a new wave of "personalized, functional" organs produced at "unprecedented speed." This could be helpful for implants and repairs, and might greatly reduce the temptation to use animal testing -- you'd just need to produce organs to simulate effects. This might be as much an ethics breakthrough as it is a technical one.