News in 3D printing, September 29, 2021: research, molds and bridges – 3DPrint.com
We start with extensive research into today’s 3D printing briefs, as scientists at Pusan National University 4D print moisture sensitive polymers and 3D printed components help improve the performance of an electrochemical reactor. Astronomers 3D print portable stellar cribs, and we’re not talking about the kind where your baby falls asleep. Hybrid AM technology is used to make molds filled with carbon fibers for an automotive project, and finally, a 21-meter-long 3D-printed bridge was unveiled in China.
4D printing of moisture sensitive polymers
Innovations such as sensors, smart textiles, flexible robots, and weather-sensitive architecture are typically based on materials that respond to external stimuli, such as light, temperature, and humidity, changing shape. Lightly crosslinked liquid crystal (LC) polymers, or LC elastomers (LCEs), have this actuation ability, but most do not respond to changes in humidity, or if they do, they are brittle. A team of scientists from Busan National university in Korea, have developed a new class of intelligent ECLs, which can be 3D printed, are highly deformable and react to ambient humidity, making them printed in 4D. First, they prepared LC ink using dimethylamino group functionalized LC oligomers, which were then 3D printed, using assisted direct ink writing technology. by UV, in a variety of geometries. Finally, an acidic solution was used to activate the 3D printed LCE surfaces, and the resulting new moisture-sensitive LCEs can undergo programmed and reversible shape changes, such as twisting, bending and forming. letters’ P ‘,’ N ‘, and you.’
“Our LCE is leading the way in the design of complex moisture-sensitive structures that can be applied to 4D printing technology. This may be one of the key materials technologies that is innovating our future for the industrial revolution, Industry 4.0, ”explained Prof Suk-kyun Ahn, who led the team.
“The day is not far away when we can see smart textiles or shoes that can spontaneously change their breathability in response to weather conditions, or flexible actuators that can operate driven by moisture, without an electric motor.”
You can find out more by reading the publications of the Pusan team to study.
3D printing improves the performance of the electrochemical reactor
Researchers from Lawrence Livermore National Laboratory, in collaboration with Stanford University and the oil and gas company Total American Services, recently used 3D printing to rapidly improve the performance of electrochemical reactors used to convert CO2 in chemicals, raw materials and energy sources. Collaborating researchers work under a research and development cooperation agreement (CRADA) and have published a paper prove that 3D printed components have enabled steam-powered electrochemical systems to produce higher yields of raw materials and fuels, such as ethanol and ethylene, and dramatically speed up the reactor building process. The team used projection micro-stereolithography and other photochemical 3D printing processes at LLNL to design and print new packages for the reactors, with the goal of finding better ways to control the environment around the catalyst. . By using the technology to optimize the design, they were able to improve overall mass transport to deliver reactants to the catalyst environment and remove products from it, as well as introduce what the researchers call a “paradigm shift approach.” for the design of future reactors. and rethinking the way chemical reactions are carried out.
“Things that happen near the catalyst and their effect on overall reactions are under-studied, so we decided this would be our niche. The community had never harnessed the power of 3D printing to accelerate this design-build-test cycle. Our team made very rapid discoveries working with somewhat ordinary, un-exciting catalysts that people have used for a long time, and with this understanding and control of the local environment, we were able to achieve properties and performance. record or almost record. Explained the co-principal investigator Eric Duoss, a research engineer who directs the center of LLNL or Engineered Materials and Manufacturing.
“We have shown this first demonstration of what can be done with CO2 reactors, but the potential impact is much greater than that. This approach will accelerate scientific discovery and technological deployment to hopefully bridge the “valley of death” and see these technologies commercialized at some point. Our climate and carbon challenges are immense, and they require these kinds of creative and disruptive solutions because we just don’t have time to wait.
3D printed portable stellar nurseries
Artist and astrophysicist Nia Imara, professor of astronomy at the University of California Santa Cruz, combined his two passions to help scientists better visualize the giant clouds of gas and dust that give birth to stars, also known as the stellar nursery. She and her team used high-resolution bitmap-based 3D printing to make polished orbs small enough to fit in your hand that look like giant marbles containing beautiful swirling patterns. Those 3D printed stellar nursery models feature models from simulations performed on stellar clouds, showing how nurseries are affected by different processes, such as magnetic fields and turbulence. Opaque resin was used to print the models, and the Amara team also printed hemispheres to provide a simulated view of cross sections of stellar nurseries.
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In a UC Santa Cruz statement, Imara explained, “We wanted an interactive object to help us visualize these structures where stars form so that we can better understand physical processes.
“If you have something winding through space, you might not realize that two regions are connected by the same structure, so having an interactive object that you can rotate in your hand allows us to detect these. continuities more easily. “
Imara plans to use the 3D printed models in an astrophysics class she will teach this fall. To find out more, you can read the published article here.
Hybrid Manufacturing Helps Restore Custom Vehicles
In June, specialist in multi-axis machining CMS SpA, based in Italy and the United States, presented its large-format composite hybrid Kreator 3D printer and multi-axis milling machine, and has now announced the first commercial project developed with this technology. In collaboration with the Italian company Bercella Srl., specializing in large and complex structures, CMS uses the new Kreator hybrid to make carbon fiber filled molds for Bercella’s custom Restomod Maserati vehicle restoration project. CMS worked with Fraunhofer IWU to develop the Kreator, which combines milling with large format additive manufacturing (LFAM), and the first use case was the redesign of 26 body components, including the bumpers, the door, roof and bonnet, for the Restomod Maserati MV 3200 GTC. Using the Kreator CMS, components were constructed from pre-impregnated carbon fibers, handcrafted on molds – 3D printed from PA6 loaded with 40% carbon fibers – then cured in an autoclave . The ultimate goal is to produce a complete carbon fiber restoration vehicle from 3D printed molds.
“We are particularly proud to be part of this extraordinary project. Sustainability and production flexibility are the keywords that we shared with Franco Bercella years ago when talking about the huge opportunities that a particular additive manufacturing solution for large formats could have brought to the composite materials sector. », Said Giovanni Negri, CEO of CMS SpA. “The Restomod project is starting to give us these opportunities firsthand.”
3D printed bridge unveiled in Chengdu
Finally, a park in Chengdu, China, now houses a 3d printed bridge it’s over 21 meters long. The bridge, 3D printed from polymer composite materials instead of concrete or metal, is actually part of the larger Liuyun Bridge in the city’s Yimahe Park. This bridge is 66.8 meters long and the flexible 3D printed part of 21.58 meters long is 8 meters at its widest point and 2.68 meters at its highest point. Made from 12 tons of ASA polymer and fiberglass for strength and weather resistance, the design team at China Southwest Architecture cooperated with a printing team in Shanghai and used the largest printer polymer of the country to build the bridge, inspired by the “free form of the Stage Horse River and dancing silk. The fully automated printing system took 35 days to complete the 3D printed part of the Liuyun Bridge.
Cheng Rui, Head of China Southwest Architecture, said, “Combining industrial-scale 3D printing with a landscaped bridge demonstrates the feasibility of ultra-wide 3D printing technology for future applications in architectural fields. and industrial.