By now, you’ve probably heard of the technology that has revolutionised the ‘maker movement’:
3D-printing.
But how does 3D-printing work? And what its potential applications?
Well today, we’re going to find out.
When you think about 3D-printing you might imagine workshops or a tech start-up,
but actually its story starts here, in the field.
Maize, or corn, is a large grain plant that was first domesticated in Mexico about 10,000
years ago. It’s cultivated in every continent except
Antarctica and we produce over a million tonnes of it every year.
And if we took all of those crops of maize and put them together in one single field,
that field would be bigger than Portugal, Spain, France, and Germany combined!
But how do we turn this into plastic?
First, the shelled corn is milled to produce starch.
This starch is then heated and enzymes are added to it
to convert it into corn sugar or ‘dextrose’.
More enzymes are then used to break apart the sugar molecules to produce lactic acid
The final reaction then links together the
individual lactic acid molecules to produce long chains of ‘polylactic acid’, or PLA for short.
This PLA bio-plastic has a wide range of applications, including 3D-printing.
Underneath here I've given you the tools to do some 3D-printing
OK.
We have some buttercream icing, some bags, some scissors.
And what I would like you to do is to 3D-print an elephant.
OK! Now this guy is made out of PLA, but I want to see whether you can do it out of buttercream icing.
I'm going to with creating a base.
Builing from the bottom up? Yes
It wouldn't be very easy to build from the top-down. Top-down would be very hard!
Now it's time for his trunk. Now the trunk.
I think that is the best I'm going to be able to recreate.
Happy? It's more Elephant-Man than elephant.
[laughing] That is very true!
With our 3D-printed elephant out of PLA, they're going up by fractions of a millimetre at a time.
So, they're building it up very very slowly.
So she is probably printed over the course of several hours, and you did that in about 5 minutes.
I mean, you can tell. [laughing] What are you saying, Ross?
Well, let's take a closer look at how 3D-printing *actually* works.
3D-printing is a form of ‘additive manufacturing’: creating three-dimensional objects by building
one layer on top of another.
But instead of using buttercream this printer uses PLA.
The coil of plastic is fed into this nozzle which heats up to 210 degrees celcius.
This is the ‘glass transition’ temperature of PLA, which turns it from a relatively brittle
‘glassy’ plastic into a molten state which can be ‘extruded’ through the nozzle and
instantly sets in place.
The nozzle can move in the x and y-axis, and bed moves up and down in the z-axis.
That way it can deposit the plastic at any point in three-dimensional space.
All we have to do is give it a set of instructions so the nozzle knows where to move.
These instructions come in the form of a 3D model like which looks like this.
All we have to do is upload the digital file and press print!
In order to support the growing structure, it will sometimes need to build a scaffold,
which is later removed. But depending on the size, complexity, and
level of detail, a single print can take anywhere from days, to just a matter minutes to complete.
But besides creating awesome sculptures, what are some of the potential applications for this technology?
As well as the creation and rapid prototyping of newly designed products here on Earth,
the international space station is currently testing whether new equipment can be printed
in space rather than shipped up into orbit.
The world of fashion is embracing the new technology to combine art and engineering.
You can even print chocolate!
Doctors and surgeons are also using 3D-printing to create individual replacements for bones
and joints. And research is currently making progress
using living human tissue to print organs for transplantation.
Here in Bristol, a company called Open Bionics is using PLA to 3D-print custom made bionic
hands at a fraction of the cost of other alternatives.
The applications seem limitless, but what do you think? What could the future hold?
What would you like to see printed? Let us know in the comments below.
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And for more tinkering videos, check out our furby dissection.
Thanks for watching!