"Experiments in printing soft tissue are underway, and may soon allow printed veins and arteries to be used in operations," they add. "Today's research into medical applications of 3D printing covers nano-medicine, pharmaceuticals and even printing of organs. Taken to the extreme, 3D printing could one day enable custom medicines and reduce if not eliminate the organ donor shortage."

"Bioprinting," which builds organic shapes from layer after delicate layer of living cells, has truly raised the stakes.

As financial journalist Russ Banham put it this past spring in a T. Rowe Price report on the burgeoning industry, 3D printing has fast evolved to a point where it's not too far-fetched to say that "the human body might someday be thought of as a system of interchangeable parts."

From prosthetics to dental implants to organs to to cartilage, an increasing number of companies are moving the technology forward. 

Rock Hill, S.C.-based 3D Systems uses printers to fabricate personalized in-ear hearing aids. Bespoke Innovations, in San Francisco, designs and prints gorgeous customized prosthetics that could easily be called art; amputees are even able to design their own. San Diego-based Organovo developed one of the first 3D bioprinters. Conjuring "living human tissues that are three-dimensional, architecturally correct, and made entirely of living human cells," officials say, its technology "has the potential to change the world."

Open source software is also playing a big role in the development of the industry, helping make for faster and more fertile innovation.

"When information can create physical products, there will be open source versions of that also, and access to 3D printing will be even more ubiquitous than computing platforms are today," famed futurist Ray Kurzweil told the Washington Post this past November.

In the meantime, the breakthroughs keep coming. This past September, nano-engineers at the University of California San Diego announced a new technology that can fabricate microscale 3D structures from biocompatible hydrogels.

"Near term, the technology could lead to better systems for growing and studying cells, including stem cells, in the laboratory," researchers wrote in a press release. "Long-term, the goal is to be able to print biological tissues for regenerative medicine. For example, in the future, doctors may repair the damage caused by heart attack by replacing it with tissue that rolled off of a printer."