Page 67 - Plastics News January 2023
P. 67
TECHNOLOGY
3D Printing Method Fabricates Complex Metal Plastic Composite Struc-
tures
Such 3D metal–plastic composite
structures have widespread potential
applicability in smart electronics, mi-
cro/nanosensing, internet-of-things
(IoT) devices, and even quantum
computing, according to the research-
ers. 3D printing these structures gives
the devices they’re put into a higher
degree of design freedom, with the
possibility more complex features
and geometry, as well as increasingly
smaller sizes. They have not been
widely adopted, however, because
the current methods to fabricate such
parts are expensive and complicated.
To demonstrate the manufacturing
capabilities of the MM-DLP3DP pro-
cess, the research team created parts
with complex structures including
multimaterial nesting layers and mi-
croporous and tiny hollow structures
— the smallest of which was 40 µm
in size. The metal patterns on these
parts were very specific and could be
precisely controlled. The team also
esearchers at Waseda University cycles and low-design flexibility. The manufactured 3D circuit boards with
Rof Japan and Nanyang Technologi- multi-step MM-DLP3DP process be- complex metal topologies, like an
cal University of Singapore recently gins with the preparation of the active LED stereo circuit with nickel and a
published a paper describing what precursors, which can be converted double-sided 3D circuit with copper.
they call multimaterial digital light pro- into the desired chemical after 3D In addition to creating highly specific
cessing 3D printing (MM-DLP3DP) printing since these chemical aren’t metal patterns, the paper notes that
— a process that can fabricate metal printable. the process results in higher qual-
plastic composite structures with ar- To achieve this, palladium ions are ity metal coatings, both of which can
bitrarily complex shapes. Waseda’s added to light-cured resins to prepare contribute to highly integrated and
Shinjiro Umezu and Kewei Song along the active precursors. This allows customizable 3D microelectronics.
with Hirotaka Sato from Nanyang electroless plating (ELP) wherein an
published the study in ACS Applied auto-catalytic reduction of metal ions The Researchers believe this advance
Materials & Interfaces. in an aqueous solution forms a metal represents a breakthrough technology
for the manufacturing of circuits, with
The researchers noted that existing coating. Next, the MM-DL3DP ap- potential application 3D electronics,
technology can manufacture 3D cir- paratus is used to fabricate micro- metamaterials, flexible wearable de-
cuits, but stacking flat circuits Is still an structures containing nested regions vices and metal hollow electrodes.
active area of research. Current tech- of resin or the active precursor. In the
nologies for fabricating such struc- final step, these materials are directly
tures tend to be expensive with a high plated, and 3D metal patterns are
degree of complexity, long production added to them using ELP.
January 2023 PLASTICS NEWS 67