[MUSIC] Now, let's take a look at the materials
that are used to create 3D printed objects. Although there are many different
types of 3D technologies, nearly all 3D printers
work in one of two ways. They either take a soft material and
make it hard, or take a hard material and make it soft. Thus, just about any material that can be
hardened or softened can be 3D printed, including plastic, metal,
carbon fiber and even chocolate. At present, the vast majority of desktop
3D printers are FDM machines such as the Ultimaker, that create objects
by softening a strand of thermoplastic. There are currently two major types
of thermoplastics, ABS and PLA. ABS stands for
acrylonitrile butadiene styrene or something like that, and
is made from petroleum. The second type of thermoplastic is
PLA which stands for polylactic acid. This is made from corn. Both ABS and PLA are very strong and
share a number of properties. For example, they have the same melting
point, come in a variety of colors, and both are used by large manufacturers
to make a variety of products. For example, if you've brought Legos,
Legos have been made with ABS plastic. Our 3D printing and hardware course will
dive into more details about the pros and cons of each of these
different types of plastics. Of the two, we recommend PLA. This is the material that we use for
nearly all of our printing. And when you melt it,
it actually smells like waffles, so has a pleasant side effect. One of the limitations of both ABS and
PLA is their stiffness. Both are quite hard and don't bend easily. For example,
this smartphone case was made using PLA. As you can see, it's not very flexible. So in recent years, a variety of different types of flexible
plastic filaments have emerged. In fact, I have one right here. Here in white,
this is a flexible filament. And as you can see, it bends quite easily. So this sort of material is really good
for making things that need to flex, such as a shoe or a ball. In addition to hard and soft plastics,
a number of mixed polymer materials are starting to appear,
such as this wood-based polymer. This gnome is printed in a polymer that
is 60% plastic and 40% wood byproduct. And as it melts,
the plastic is melted away and you're left with the wooden product. In addition, there is concrete polymers
and polymers that look like bronze. The range of materials that can be heated
up and melted through an FDM printer, such as this, will continue to
increase in the coming years. So the capabilities of the machines
will be quickly expanding. One of the frequent questions that
those new to 3D printing often ask is, how much does this material cost? Well, what would you think that
a roll of PLA or ABS would cost? This is a kilogram. Well, in actuality, the cost of this material is much
cheaper than most people think. A kilogram of thermoplastic typically runs
for about $20 US, which is $0.02 a gram. As a point of reference,
a typical smartphone case such as the one I have here,
weighs between 20 to 25 grams. Thus, you can print a case for
your phone for less than $0.50, which is a lot less than you
would pay if you bought one. Thus, 3D printing objects is typically a
lot cheaper than buying them from a store. [MUSIC] [SOUND]