Everyone is now aware of 3D printing. It’s in the papers, all over the Internet and even on TV. Whilst we’re still a long way off DIY 3D printing becoming commercially viable (and useful, for that matter) we’re still seeing more and more prototypes and advancements being pushed forward with 3D printing.

Much like when regular printers first came around, they were used for years commercially, and they were huge and expensive. But with time and research the printer became a normal part of the home and office, so maybe one day we’ll see the 3D printer all over the place – with people downloading designs, making their own on CAD, printing them out at home or at local 3D print shops.

We’ve seen some fairly exciting and wacky 3D-printed objects and prototypes recently, so I’d thought I’d give you a rundown of my five favourite ones.

5. 3D Aston Martin

A computer programmer from New Zealand has begun printing plastic parts to form a 1961 Series II Aston Martin DB4.

Ivan Sentch has been working since January 2013 on the replica, which will cost a fraction of the price of a real Aston Martin worth between £220,000 to £1.2m.

Sentch, who has no previous experience of 3D printing, began the process of printing out individual 4-by-4-inch sections, then mounting them on the wooden frame and gluing each piece into place.

So far, with 2,500 fiberglass molds printed, he is currently 72% of the way to completion.

In an interview with MAKE magazine, he said: "I was told to expect $12K to $15K NZD for a CNC-cut plug, which nearly killed the project idea but, somehow, I had the thought to look into 3D printing as an alternative and, after researching it, it was only going to cost me $2K in plastic and the cost of the printer, which I can use for other things like making a replica dash and what not."

Sentch, who expects to finish the project within four or five years, still has to develop the dash and other interior and exterior bits as well as sanding, and painting.

His website, Replica DB4 Project, has reported on the project since he started it in his garage and how has an international following.

4. Space food replicator and 3D parts-maker

A 3D printer is bound for the space station in 2014 after passing a series of key microgravity flight tests.

Three prototype versions of space manufacturing startup Made in Space’s 3D printer showed their stuff during four airplane flights that achieved brief periods of microgravity via parabolic maneuvers.

"We demonstrated that our 3D printers can print in microgravity," Made in Space strategic officer Mike Chen said in a statement.

"Next year, we will demonstrate that they can print on the International Space Station."

The main goal of the project is to help jump-start an off-planet manufacturing capability, which proponents say could aid humanity’s push out into the solar system by making living in space easier and cheaper.

"The 3D printer we’re developing for the ISS is all about enabling astronauts today to be less dependent on Earth," Noah Paul-Gin, Made in Space’s microgravity experiment lead, said in a statement.

"The version that will arrive on the ISS next year has the capability of building an estimated 30 percent of the spare parts on the station, as well as various objects such as specialty tools and experiment upgrades."

NASA seems convinced with 3D printing’s potential. For example, the space agency also recently funded the development of a prototype 3D printer designed to make space food products out of cheap raw materials that have a long shelf life. They gave $125,000 to a Texas based company that they hope one day can provide the ability to feed astronauts on longer missions, such as a a manned mission to Mars.

3. 3D Gun

In May of 2013, the world’s first gun made with 3D printer technology was successfully fired in the US. Created by ‘Defense Distributed’, a controversial group from Texas that spent a year on the project, it was made on a 3D printer that cost $8,000 (£5,140) from the online auction site eBay. To make the gun, Mr Wilson received a manufacturing and seller’s licence from the US Bureau of Alcohol, Tobacco, Firearms and Explosives.

Now at this price, yes, you may as well just buy a conventional gun, but critics are worried about what this will mean in the future if people can just ‘print off’ weapons.

A Canadian man has recently posted a video of himself firing rounds from a 3D-printed rifle. It was made on a Stratasys Dimension 1200es 3D printer, a professional-grade fabrication device that can be purchased for about $10,000.
Gun control advocates and some security officials fear that such weapons, which do not set of metal detectors, could be sneaked into airports and other high-security areas without detection.

The man who designed the plastic rifle calls his creation ‘the Grizzly,’ named after the Canadian-built M4 Sherman tanks that helped liberate France during the Second World War.

2. 3D-printed rocket engine components

The largest 3-D printed rocket engine component NASA has ever tested has blazed to life during an engine firing that generated a record 20,000 pounds of thrust.

This test is a milestone for one of many important advances the agency is making to reduce the cost of space hardware.
Innovations like additive manufacturing, or 3-D printing, foster new and more cost-effective capabilities in the U.S. space industry.

"This successful test of a 3-D printed rocket injector brings NASA significantly closer to proving this innovative technology can be used to reduce the cost of flight hardware," said Chris Singer, director of the Engineering Directorate at NASA’s Marshall Space Flight Center in Huntsville Alabama.

The component was manufactured using selective laser melting. This method built up layers of nickel-chromium alloy powder to make the complex, subscale injector with its 28 elements for channeling and mixing propellants.

The part was similar in size to injectors that power small rocket engines. It was similar in design to injectors for large engines, such as the RS-25 engine that will power NASA’s Space Launch System (SLS) rocket for deep space human missions to an asteroid and Mars.

"This entire effort helped us learn what it takes to build larger 3-D parts — from design, to manufacturing, to testing," said Greg Barnett, lead engineer for the project. "This technology can be applied to any of SLS’s engines, or to rocket components being built by private industry."

One of the keys to reducing the cost of rocket parts is minimizing the number of components. This injector had only two parts, whereas a similar injector tested earlier had 115 parts. Fewer parts require less assembly effort, which means complex parts made with 3-D printing have the potential for significant cost savings.

"We took the design of an existing injector that we already tested and modified the design so the injector could be made with a 3-D printer," explained Brad Bullard, the propulsion engineer responsible for the injector design. "We will be able to directly compare test data for both the traditionally assembled injector and the 3-D printed injector to see if there’s any difference in performance."

NASA seeks to advance technologies such as 3-D printing to make every aspect of space exploration more cost-effective. This test builds on prior hot-fire tests conducted with smaller injectors at Marshall and at NASA’s Glenn Research Center in Cleveland.

Marshall engineers recently completed tests with Made in Space, a Moffett Field, Calif., company working with NASA to develop and test a 3-D printer that will soon print tools for the crew of the International Space Station. NASA is even exploring the possibility of printing food for long-duration space missions.

1. 3D Ear

Scientists have actually grown a human ear built from a mould created by a 3D printer!

The team from Massachusetts General Hospital had a plastic surgeon help with the design of the ear model to ensure the shape and proportions were correct before printing it as a mould.

This was then cast in a special silicone compound and split along the outer contour, giving them two separate moulds.

These were lined with wire to keep their shape and filled with cow collagen, which gave them elasticity and strength, before the researchers took ear cartilage cells from sheep.

The cells were then grown inside rats until the team had enough cartilage to replace the cow collagen inside the ears, and they said the ears had enough definition in the curves and lines to be recognisable even after a layer of skin had been applied.

The scientists reported that the ears responded well to stress tests, keeping their shape.

The development shows the extent to which 3D printing can be used to create precise moulds for such uses, and perhaps foreshadows an increasing use of the technology in science.

At the start of July scientists at Princeton University sent cow cells mixed with a liquid gel through a printer, then tiny particles of silver, and printed out a ‘bionic ear’, with the silver forming a coiled antenna.

A startup called Modern Meadow is hoping to bioprint artificial raw meat and company Organovo Holdings has the ability to print a variety of human tissue and cell types.

The future could be rather spectacular, with the potential there to theoretically print real living tissue prosthetics and, one day perhaps, even working organs.