Additive manufacturing has dominated newspaper headlines and social media feeds over the past few years with a wave of attention-grabbing things that 3D printing can build -- food, figurines, musical instruments, eyewear, weapons, even human skin.

The technology of translating a digital CAD model into a physical object, layer by layer from the bottom up, was actually born in the mid-1980s when engineer Chuck Hull developed a process called stereolithography (SL). And for a majority of the past 30 years, it has remained in the commercial industry as a tool for rapid prototyping. That began to shift when significant 3D printing process patents started expiring five years ago, offering a new level of accessibility, and subsequent visibility, due to the drastically reduced cost of consumer-level 3D printers.

In 2009, a major patent for fused deposition modeling (FDM) expired. That pushed the additive door wide open for a culture of inventors and entrepreneurs -- known as the maker movement -- who were more than willing to embrace FDM and the creative (and financial) possibilities it presented. FDM uses a spool of plastic filament or metal wire extruded from a nozzle into successive cross-sectional layers that form three-dimensional shapes. It's a process that many desktop 3D printers now use, from numerous crowdfunded machines on Kickstarter and Indiegogo to popular MakerBots that are produced by Stratasys.

Earlier this year, another important patent lapsed, this time involving the SL process of solidifying layers of liquid thermoplastic resin with a fine ultraviolet laser. A second critical patent followed suit in June on a process that fuses thermoplastic nylon powder in layers called selective laser sintering (SLS). According to industry expert Terry Wohlers, from independent consulting firm Wohlers Associates Inc., this could signal more changes for 3D printing. We may now see fairly significant progress around SLS in the future, he explains, but due to a complicated build process that involves detailed temperature and powder control, we should anticipate a more gradual increase in the technology compared to FDM.

DIY inventors aren't the only ones exploring 3D printing. Massive organizations like General Electric and NASA are making substantial investments in the technology. GE's annual investment in global additive manufacturing research and development is now a staggering $6 billion, and it estimates that its aviation division will have printed 100,000 parts by 2020. That type of additive production will no doubt be spurred by new GE Aviation facilities like the recently announced $50 million plant in Auburn, Ala., which will begin printing fuel nozzles for jets in 2015.

And 3D printing isn't just limited to confines of Earth. NASA is on the verge of sending a fully functional printer, developed by Made in Space, to the International Space Station. The machine will use extrusion-based printing in microgravity for astronauts needing on-demand shuttle parts. Among other things, NASA is also working on a space telescope built almost entirely out of 3D-printed parts and it co-hosted a contest with MakerBot where there they solicited prototype housing designs for a Martian colony; the winning design was a uranium-bioshielded modular honeycomb that featured all of the household amenities of earthly living.

How about something that sounds even more like it was yanked out of a science fiction film? Try 3D-printed organs. Additive prosthetics, in different forms and with different functionality, have been available to amputees for a while now, but scientists have also been tackling the more challenging internal task of creating live human tissue with bio-printers (layering of cells, not plastic). It's in an effort to move toward fully printed organs one day; but building functional livers, hearts, and other organs from bio-printers that can be sustained within a human being is still a ways off.