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Materials Science in Additive Manufacturing Additive manufacturing of active optics

and precision, making it a popular choice for integrating of inkjet printing also allows for the integration of
functional materials such as luminescent polymers and optical elements into complex circuits, making it a
QDs into optoelectronic devices. valuable tool for applications in displays, sensors, and
While DLP is a highly versatile and precise technique, telecommunications. 101
it faces challenges such as a reliance on photopolymers, While both DIW and inkjet printing provide powerful
which limits material diversity, and difficulties in achieving tools for fabricating advanced optoelectronic devices,
uniform light curing over large build areas. Surface they face challenges that researchers are actively working
defects and resolution inconsistencies caused by layer-by- to address. For DIW, improving the printing resolution
layer processing also remain areas of concern. Ongoing without compromising the ability to handle highly viscous,
research aims to address these issues by developing hybrid multi-material inks is a key focus. For inkjet printing,
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resin systems with improved thermal and mechanical enhancing the uniformity and reliability of droplet
stability and exploring advanced projection techniques deposition, particularly for larger-scale applications,
to enhance light uniformity and resolution. 97-100 These remains an important area of innovation. In addition,
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innovations are expected to expand DLP’s capabilities efforts are being made to expand the range of compatible
for fabricating scalable, high-performance optoelectronic inks by developing formulations with improved thermal
devices in applications such as displays, sensors, and stability, mechanical robustness, and functionality. These
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telecommunications. advancements aim to unlock the full potential of DIW
and inkjet printing in producing next-generation light-
5.3. DIW and inkjet printing emitting devices for photonic and optoelectronic systems.
DIW and inkjet printing are both additive manufacturing
techniques that involve the deposition of functional 5.4. 2PP
inks to build structures, but they differ in terms of their 2PP is a high‑resolution additive manufacturing
mechanisms and applications. DIW involves the extrusion technique that utilizes femtosecond laser pulses to initiate
of ink through a nozzle to form 3D structures layer-by-layer, polymerization within a photosensitive material. This
making it particularly effective for creating multi-material method allows for sub-wavelength resolution, enabling the
devices with intricate geometries. Inkjet printing, on the fabrication of highly detailed micro- and nanoscale optical
other hand, uses a non-contact approach, where droplets components. 2PP has been employed to create fluorescent 3D
of ink are precisely deposited onto a substrate, allowing for metastructures with complex geometries and high precision.
highly controlled patterns. Both methods have been widely An example of this is the additive manufacturing of
adopted in the fabrication of light-emitting devices due to highly fluorescent organic 3D metastructures, where
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their ability to incorporate advanced materials, such as 2PP was used to achieve sub‑wavelength resolution for
QDs and organic semiconductors. light-emitting devices, enhancing the design of micro-
In the field of optoelectronics, DIW has been used optical components for advanced photonic applications.
to fabricate QDs LEDs by depositing QDs inks in However, like many emerging technologies, 2PP
high-resolution patterns. These 3D-printed QD-LEDs faces challenges in scalability due to its relatively slow
demonstrate the flexibility and performance required for fabrication speeds, which limit its practicality for large-
applications such as displays and sensors, with tunable scale production. Material compatibility is another
light emission properties and efficient material utilization. limitation, as it relies on photopolymerizable materials,
The precise material placement enabled by DIW allows restricting the range of usable materials. Despite these
for the creation of complex, multi-functional devices that challenges, significant progress has been made. High‑
integrate optical and electronic elements within a single speed scanning systems and parallel multi-beam setups are
structure. 57 addressing throughput concerns, while the development
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Inkjet printing complements DIW by offering a highly of advanced photoresins and hybrid materials is expanding
scalable, low-cost method for producing optoelectronic material versatility. These advancements demonstrate
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components with excellent spatial control. Inkjet printing the potential for 2PP to transition from research‑focused
has been used to fabricate organic photonics, such as applications to industrial-scale production of high-
microring lasers and integrated circuits, where organic performance optical devices.
and QD materials are deposited in precise configurations.
This technique is particularly suitable for wearable and 5.5. SLS
flexible devices, as it enables the direct printing of light- SLS is a powder-based additive manufacturing technique
emitting materials onto soft substrates. The precision that uses a laser to selectively fuse powdered materials

Volume 3 Issue 4 (2024) 16 doi: 10.36922/msam.5748