European Space Agency 3D Print lunar base
Printing a base on the moon could make the building process much faster and efficient. ESA

A printer was once just a printer, dispensing paper sheets with printed material made from the ink stored within.

But today, a printer has evolved to becoming a small-scale manufacturer that 'prints' out anything from human organs to affordable meals to guns.

For instance, the XYZPrinting 3D Food Printer, exhibited at the recent CES 2015 in Las Vegas, is expected to print any style of uncooked cookies and other dough-based pastries in minutes.

Not exactly as affordable as any other food processor, the printer ranges between $500 and $1,900 and prints food that measures around 5000 cubic cm by volume.

However, the food printer is not to be compared to a processor. All it does is to design the end product when the base product is ready. Shaping, colouring, sizing, that's about what the printer does.

Unlike food that finally has to be cooked after it is 'built', socket wrenches and human organs can be completely made by the printer using the additive layering process. Mini-castles of cement and sand have been built already.

When the ISS space station commander, Barry Wilmore urgently needed a ratcheting socket wrench, all that was done is to email the tool design along with the blueprint.

Another 3D printer sprays milk and chocolate to make available the Hershey taste at the press of a button on the CocoJet. It is built by 3D Systems, which is already selling the Ekocycle, a $1,200 3D printer that uses recycled material.

The materials were applied layer by layer based on the blueprint.

Living organ to be 'printed'

So also with the first living organ to be soon created using a 3D-bioprinter.

Russian scientists say the printer will create a transplant-ready thyroid first and follow it up with a functional printed kidney scheduled for 2018.

The bioprinter will be using stem cells as an 'ink' to make the thyroid gland.

Stem cells obtained from fat tissues will be transformed into spheroids or an aggregation of cells, which will be layered as per the design onto hydrogel. The gel then dissolves, and the printed organ matures in a special bio reactor.

More dangerously is how 3D printing allows one to make a gun at home. US firm Defense Distributed has developed a milling machine which allows buyers to print and assemble a steel AR-15 rifle right at home.

The 3D printers are not really new and have been used for some time now to create prototypes in manufacturing and research. It helps save money and time in actual prototyping of the product at the factory.

Companies have also been using 3D printers for short run custom manufacturing.

Nothing new

Largely meant for design visualisation, metal casting, geospatial mapping, palaeontology, forensic pathology, 3D printing has only now begun to catch popular imagination, thanks to cakes and cookies and lawn mowers made by a printer.

Computer-aided tissue engineering has been making organs and body parts using inkjet techniques, mostly for research.

Basically, 3D printing or additive manufacturing is a process of making three dimensional objects from a digital file.

The object is created by laying down thin successive layers of material until the entire object is created using inbuilt hardware.

The software slices the final model into hundreds or thousands of horizontal layers. When uploaded in the 3D printer, the printer creates the object layer by layer.

One of the commonly used technology, selective laser sintering (SLS) uses a high power laser to fuse small particles of plastic, metal, ceramic or glass powders into a mass that has the desired three dimensional shape.

The technique

The laser selectively fuses the powdered material by scanning the cross-sections (or layers) generated by the 3D modeling program on the powder bed.

After each cross-section is scanned, the powder bed is lowered by one layer thickness. Then a new layer of material is applied on top and the process is repeated until the object is completed.

Most of the printers making cakes and goodies use water and dry powder ingredients like flour and sugar in the same layering process explained above.

Where the Ink-Jet printer that we use for documents has four tanks of ink (Magenta, Cyan, Yellow and Black) picked up by the printing head and shot in fine droplets as it moves across the paper horizontally, the food printer would use chocolate, cream, vanilla, etc.

The printing head now shoots edible substances in layers as per specifications.

Once the layering is complete, all you need is to bake the cake.

As far as cakes go, the printer is more of a shape provider that also mixes the ingredients.

Eventually, when they are mass produced and cheaper to buy it is expected that 3D printers will change the nature of commerce, with end users doing much of their own manufacturing.