The Current State of
By Cullen Hilkene, 3Diligent Corp.
Industrial additive manufacturing has emerged from the trough of disillu- sionment and is now experiencing a
renaissance of sorts. This is in good part
due to a proliferation of industrial printer
manufacturers with new technologies
and more open approaches to materials
From my vantage point at 3Diligent, a
rapid manufacturing service provider that
helps companies with their 3D printing
projects, one industry in which additive
manufacturing applications are especially
prevalent and gaining acceptance is the
Since 3D printing builds objects one
voxel (3D pixel) at a time, it is uniquely
suited to construct complex organic shapes
that are implausible or impossible with traditional manufacturing techniques. These
shapes can, for instance, contain intricate
internal geometries and custom-tailored
porosity to mimic different bone densities.
Moreover, this complexity is available
virtually free of charge.
Recognizing the value proposition and
economics are compelling for the medical
community, are the currently available materials sufficient to meet market demands?
Which materials are currently available?
Which are still to come? This update on
the state of the 3D printing materials market will show that there are more available
now than is generally perceived, and more
are rapidly on the way.
Aqueous Solutions/Bio Inks
Aqueous solutions – sometimes referred to
as bio inks within the 3D-printing domain
- include Poly (2-hydroxyethyl methacry-
late) (pHEMA) and Polyethylene (glycol)
Diacrylate (PEGDA). However, this is an
area of vast investment and research with
many promising new hydrogel materials
These are commonly printed using
pneumatic or hydraulic extrusion. This can
be at room temperature to preserve living
cells, for instance, or through a heated
nozzle. Aqueous solutions can also be “
indirectly” 3D printed, in the sense that part
patterns can sometimes be fabricated with
high-accuracy wax or resin printers, and
those are in turn used to create transparent
molds. The aqueous solutions can then be
poured into the transparent mold and cast,
typically with the use of UV light.
Applications for these solutions are
wide, as the material range is virtually
unlimited, so long as the active agent/ma-
terial can be carried in water. In the case of
reconstructive surgery, bone material can
be carried within a hydrogel and printed
onto bone. The deposited material can act
as a binding agent between bone frag-
ments, facilitating the ingrowth of bone to
reconnect previously shattered bone.
Thanks to their versatility and relatively
low cost, the number of medical applications for polymers is growing rapidly.
Low melting point polymers are often
printed using extrusion technologies –
otherwise referred to by brand names like
Fused Deposition Modeling (FDM) or
Fused Filament Fabrication (FFF). The
most popular biodegradable polymer is
Polylactic Acid (PLA). It is the default
material for many desktop FFF printers.
Due to that position in the market, it has
Figure 1. Researchers from Harvard utilize extruded bio inks to print various organic
shapes, including this proximal tubule, a critical component of kidney nephrons.