9 unlikely objects that can now be 3D printed

Wearables and medical devices are a natural fit for 3D printing. The smart mask from startup Sendinaden allows you to monitor your own breathing habits, which can have profound implications for mental and physical wellbeing. The device, which is derives its functionality and durability from an innovative filament from Polymaker, is slated for release in early 2016. CEO David Hartmann believes that customization is the big advantage 3D printing has over injection molding. "We see a consumer experience where you walk into a retail outlet, get a Pattern Breathe Mask curated and customized for you, go shopping and come back 45 minutes later to pick up your finished 3D printed mask."

Last year, Shanghai-based WinSun Decoration Design Engineering Co. announced that it had 3D printed 10 functional houses costing less than USD $5000 each. WinSun followed up this year with a six story apartment building it claims is the highest 3D printed structure in the world. The homes are printed in modular blocks using an ink made of concrete, fiberglass, water, sand, and a special bonding agent.

Lots of companies are busy trying to automate food preparation, so don't be surprised if a robot serves up your next burger. Edible inks are still in their early phases, but if you want something sweet, you can't do better than something printed by one of 3DSystem's machines. The ChefJet Pro, which adds to a lineup that includes the CocoJet 3D printer, prints full-color sugar, candy and frosting with an added single flavor. The machine can make about 100 candies per hour in all kinds of 3D configurations.

With Nike COO Erik Sprunk speculating that consumers in the sneaker game will soon be able to print an entire pair of shoes at home, it's clear there are big changes in store for the way shoes are made. Because shoes need to accommodate the huge degree of dimensional variance present in the southernmost region of the human anatomy, manufacturing custom kicks to order is an attractive proposition. A Tennessee startup called Feetz has raised over a million dollars in its bid to become the first digital cobbler. Customers will submit three photos of their feet, choose a style and design, and receive a customized pair of shoes in the mail.

Like shoemakers, retail clothing companies are forced to make concessions when it comes to a close fit. But what if you could get sized, choose your item, and watch it appear before your eyes? That's the dream of San Fran startup Electroloom, which has developed a way to 3D print textiles. But some designers are going even further. The bikini in the photo, created by UC Riverside engineers and design firm Eray Carbajo, was 3D printed and incorporates a special sponge-like material that cleans water as the wearer swims. Practical and chic!

Audi has printed a miniature version of a 1936 Grand Prix race car. The rolling model is made of metal using Audi's new 3D printer, which uses a laser to melt steel or aluminum metallic powder and create objects with incredibly high resolution. The process is called "sand-printing" and can make metal forms as long as eight inches, significantly reducing the amount of time engineers need to spend machining parts during prototyping.

Sweden-based Odd Guitars makes some pretty gnarly axes. The instruments, which cost between USD $3000 and $4000, employ elaborate hollow-body designs that would be all-but-impossible to produce without the aid of CAD software and a 3D printer. Odd has also made 3D drum kits, saxophones, and keyboards.

3-D printers typically produce hard plastic objects, but researchers at Carnegie Mellon University have found a way to produce hair-like strands, fibers and bristles using a common, low-cost printer. "You just squirt a little bit of material and pull away," said Gierad Laput, a Ph.D. student in Carnegie Mellon's Human-Computer Interaction Institute (HCII). "It's a very simple idea, really." The process can be used to produce everything from natural-looking hair to toothbrush bristles.