Cellink INKREDIBLE - Understanding Slicing

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To bioprint anything, computer-based models need to be converted into a series of
instrucons that the bioprinter can follow to make an object. The denions below are
meant to explain why slicing is a necessary process and why models cannot be directly
transferred to the INKREDIBLE for prinng.
7.1.1 Models
3D computer models represent objects or
geometric volumes. These models can be
generated from image stacks like CT scans and
MRIs or from design soware on a computer
(CAD). Numerous le 3D model le types exist
for use with dierent kinds of CAD soware,
each diering by the mathemacal expressions
used to store them on the computer. For 3D
prinng, the le most commonly used is a
Stereolithography or STL le. An STL, in general,
is a list of Cartesian coordinates grouped in
threes to represent triangles. Edge-to-edge
contact of these triangles forms a mesh that
denes the exterior of an object.
7.1.2 Slices
The INKREDIBLE is a pneumacally driven bioprinter that extrudes material in thin strands.
To build a model, the INKREDIBLE must extrude
a series of strands in disnct paths such that the
printed material looks like the model desired. An
STL le does not have the informaon needed
for the INKREDIBLE printhead to follow these
disnct paths. In addion, as a hollow mesh, the
STL lacks the inner structure informaon needed
to prevent the top of the print from collapsing on
itself. Slicing soware breaks an STL into a vercal
stack of paths that the INKREDIBLE can follow to
both produce the exterior of an object and the
inner structure to support it. Each path is broken
into a list Cartesian points for the INKREDIBLE to
follow called G-codes. The full list of INKREDIBLE
movements and acons is called a G-Code le.
7.1 What is Slicing?