3-D Printers and the Cool Stuff They Make

Three-dimensional printing is gaining traction in both the business realm and among consumers, but there is still some confusion about how these machines work and what exactly the printers can build.

While lots of attention has been focused on 3-D printers and printing off weapons, the fact is the machines are capable of fabricating a variety of products—from gadgets and clothing to human tissue. One 3-D printing company even printed off a concrete house.

(Read More: DIY Weapons: Start-Up Aims to Grow 3-D Gun Printing)

In 3-D printing, also known as additive manufacturing, a product is created layer by layer. The printer uses a blueprint of a digital model to make the item one layer at a time. Printers have been designed to use different materials—including plastic, ceramic, silver, steel, concrete and even stem cells— to make products.

Here's a look at how four companies are using the technology to create the future.

Makerbot, a New York-based company, builds 3-D printers for researchers, designers, engineers and consumers who want to make their own products.

Its machines use plastic to build items that are designed with the company's software.

Some companies, including Ford Motors, use Makerbot's technology to build prototypes of products. However, the machines can be used to make much more than prototypes.

Makerbot's sister website Thingiverse is a site where users can share their designs so that other users can download the template for the item and print it off with their own machine. Products on Thingiverse range from works of art and fashion items to gadgets and household goods.

Shapeways is 3-D printing company focused on bringing the technology to the masses. The company doesn't sell printers, but rather acts as a service company, allowing people to design and sell their own products. Shapeways manufactures the items with its printers and then ships it to the consumer.

Shapeways is kind of the Amazon of 3D printing. People can go there to buy almost anything. Anyone can use Shapways' platform to sell products they have designed.

Users simply design an item, upload it to Shapeways website, choose what material they want it made in and then place their order to the company. The user can then choose if they want to sell the item on Shapeways' marketplace website to other consumers.

The designer can decide the selling price of the product and Shapeways will print and ship the orders. The company only charges the designer the cost of materials for manufacturing, so the creator gets to keep the difference as profit.

Shapeways' printers can print products in variations of plastic, stainless steel, sterling silver, colored sandstone and ceramic.

The biggest products that can be printed off at one time with Shapeways' printers measure about 27-by-15-by-23 inches, however, parts of a product can be printed off to create a larger item.

Jewelry is a popular product Shapeways manufactures.

Shapeways printed off a dress designed by New York designer Michael Schmidt and architect Francis Bitonti for burlesque dancer Dita Von Teese. The company printed the nylon dress in 17 pieces and then the segments were hand-linked together.

A 3-D printed bikini, designed by Continuum Fashion, was also printed by Shapeways using Nylon 12, a material that is waterproof.

Three-dimensional printing has been used in the medical industry to print prosthetic limbs, dental fixtures and custom hearing aides for some time. The San-Diego based company Organovo, though, makes printers that build smaller, more complex structures—specifically human tissue.

(Read More: How 3D Printers Are Reshaping Medicine)

Organovo's bioprinters use "bio-ink," which is made of living cell mixtures, to create human tissue. The bioprinter prints a 3-D structure of cells layer by layer to create tissue.

Researchers at Cornell University recently used the technology to print off a functional ear.

Researchers hope to use this technology to eventually develop functional organs—like kidneys and hearts and livers (pictured here)—for organ replacement.

D'Shape is an Italian company that focuses on using 3-D printing technology to build large structure, like statues and even buildings.

The company uses its 20-by-20-foot printer to make concrete structures.

D'Shape has built art installations, furniture and even a small house using its technology.