Awesome 3-D printing tech we can’t show you on TV – yet

The consumer 3-D printing revolution may just be starting to take off, but that doesn't mean that experts familiar with the technology aren't already dreaming big for its future. In many cases, they’re dreaming way too big — or at least too conceptually — for us to capture with our cameras.

Here are three cutting-edge uses you won’t see on "TechKnow" (yet) that those working in the field hope to see in the not-so-distant future.

1. Advanced bio-printing

One of the biggest challenges facing patients who are on a waiting list for a donor organ is the problem of compatibility. Even if they've waited until they're at the top of the list, there's no guarantee that their body will accept the new addition. In the future, scientists hope that 3-D bio-printing will be able to take a few cells from the patient's body and grow new ones to print a replacement organ that won't be rejected. One engineer at Princeton has even recently printed an ear complete with an embedded wire coil that could theoretically provide the recipient with a range of hearing that exceeds our own. If this can be done with other organs as well, we may see a future in which we upgrade our bodies with printed organs in much the same way we upgrade computer hardware today.

2. Off-Earth repairs

A major limiting factor for outer space discovery and exploration is that anything we send into orbit must withstand the stresses of being launched on a rocket out of the atmosphere. However, if NASA were able to manufacture ships and parts in orbit, that would open up a new world of possibilities. This year the space agency is planning to send its first printer to the International Space Station to test how it works in zero gravity. Should it prove successful, this technology could vastly expand human capabilities in space exploration.

3. Printing entire buildings

Another term for 3-D printing is "additive manufacturing." This is because, rather than taking a piece of raw material and carving or molding the desired shape out of it, the technique adds everything precisely layer by layer without any waste. This could potentially be a game changer for the construction industry if materials such as cement could be fed into a multistory printer that would then layer up the walls — much like an enormous hot glue gun. If it were scaled up, the setup could one day make it possible to "print" whole apartment buildings and homes at a fraction of the current cost, bringing better shelter to many of the world’s most vulnerable populations.