From working guns to bionic ears, 3-D printers are creating a variety of objects and revolutionizing manufacturing processes.

But 3-D printers aren't just laying down plastics, resins and nanoparticles — they're also printing with dough, vegetables and even meats.

Both engineers and gourmet chefs are experimenting with creating foods from 3-D printing. The technique allows them to produce foods in unique shapes and textures and to streamline repetitive tasks like filling ravioli.

3-D food printers don't look like traditional printers. They’re more like industrial fabrication machines with syringes.

Users load the syringes with raw food "ink" — dough, chocolate or anything with a liquid consistency — and the machine "prints" the food by depositing layers of liquids to build the desired object.

Just like a regular printer, the machine takes its instructions from a computer. Using software, a 3-D representation of the food is created and divided into printable layers.

Designers of commercial 3-D printers believe that in the near future we'll be able to download such "recipes" and print them in our home kitchens.

FoodiniBarcelona-based company Natural Machines says it hopes its Foodini machine (pictured right) will promote more home cooking by managing the difficult or time-consuming parts of preparing homemade food.

"Rather than buying pre-packaged, processed snacks like pretzels, breadsticks, crackers and cookies, you can make them with fresh ingredients at home," the Foodini's description reads.

Printed foods could also lead to more sustainable food sources, according to Dutch technology company TNO. Its researchers have experimented with creating foods from algae, insects and grasses.

"I'd rather that instead of printing a steak from cow protein, you could make it from algae or insects," Kjeld van Bommel, a TNO researcher, told Popular Mechanics.

In one example, his group printed shortbread cookies made with milled mealworms.

"The look of the worms put me off, but in the shape of a cookie I'll eat it,” he said. "You eat with your eyes."

Take a look at the variety of food that can be made with 3-D printers.

printed chickpea nuggets

printed chickpea nuggets

Photo: Natural Machines

The Foodini made these chickpea nuggets as a healthier alternative to meat options. The machine can also print traditional chicken nuggets.

printed pizza

printed pizza

printed pizza

printed pizza

Photo: Natural Machines

Why call for delivery when you can print your own pizza?

printed cheeseburger

printed cheeseburger

Photo: Natural Machines

The Foodini printed this burger and then added cheese to fit the patty.

printed spinach quiche dinosaurs

Photo: Natural Machines

Natural Machines created these spinach quiche dinosaurs to encourage kids to eat their vegetables.

printed carrots

Photo: TNO

TNO has experimented with printing pureed vegetables back into their original shape.

printed ramen noodles

Photo: Fab@Home

Cornell University's Fab@Home can print ramen noodles in a variety of artistic shapes.

printed ravioli

printed ravioli

Photo: Natural Machines

Making homemade ravioli can be a time-consuming process, but Foodini prints each individual piece and even keeps them warm until it's time to cook.

printed spice bites

Photo: TNO

These spice bite treats were printed in shapes that would be diffult to create through traditional food-making processes.

printed chocolate

Photo: Natural Machines

printed chocolate

Photo: Natural Machines

printed cookies

Photo: Natural Machines

Chocolates, cookies, pastries and other sweet treats can be made in detailed shapes and designs that would be impossible to create without 3-D printing.

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