272
Q. Alkhalaf et al.
Table 2 Summary of agents used in material processing
The agents or photoinitiators
Advantage
Disadvantage
Platinum catalysts
• It is using for
crosslinking the PDMS
• It’s costly
Curing agent (Dow corning) [11] • It applied to cured
specific type of PDMS
such as Sylgard
• It takes a lot of time to cure
PDMS
TPO-L [9, 14]
• Improving absorption
and optical
transparency
• Improving the
resolution, the
penetration depth will
be increased
• Add the Orasol Orange
with TPO-L in PDMS
to increase the
resolution
• The higher amount of
TPO-L gives fast
curing
• The wavelength for the
light it can absorbance
is 385-400 nm
• When increasing the TPO-L
above 0.6, the optical
transparency decreases
• The solubility in PDMS is
limited
Hydroxy-2-methylpropiophenone
(2H2M) [13]
• Increase the absorption
for PDMS
• Applied in LOPP
system
It’s not sufficiency to cure
PDMS; it should add
N-vinyl-pyrrolidone (NVP) to
advance the curing
Irgacure 819 [15]
• Absorption of the light
happens in the visible
light area
• It can be applied with
resin, which has a
higher reactive
• It’s cheap
• No-toxicity
• The amount of Irgcure 819
effect on the maximum strain
and tensile strength
• Irgcure 819 isn’t sufficiency
for curing the PDMS it should
add other materials for
examples: SilOHflex
Polyethylene Glycol (PEG) [22] • Increase Yield stress
for PDMS
• It can get high quality
when controlling the
amount of PEG
• Achieving a right ratio
mass without failing
the layers
The need for adding silica
particles for achieving perfect
printing