Unique method to fabricate freeform structures of thermoplastics in microparticulate gels
3D printing of polymer inks in embedding media to fabricate freeform and overhang structures may find applications in rapid prototyping of actuators and antennas
2021-04-08
(Press-News.org) Fabrication of 3D freeform structures of thermoplastics involving overhang (non-anchored) structures is successfully showcased by fused deposition modeling (FDM) and direct ink writing (DIW), yet limited in terms of applicable materials and conditions of printing. 3D printing of freeform structures requires support materials that enable printing of thermoplastics in non-anchored locations.
In order to address the difficulty of freeform fabrication via extrusion-based printing, the use of microparticulate gels as embedding media has been widely explored. Such methods are collectively termed embedded 3D printing (e3DP).
In these demonstrations, the gels behaved as Bingham plastics with a low modulus and low yield stress during the printing of low-viscosity resins. e3DP enabled the freeform fabrication of different materials such as silicones, hydrogels, casting alloys, colloids, and hydrogels containing living cells.
Despite all these successful studies, freeform fabrication of thermoplastics has not been demonstrated with e3DP. This is because the molten thermoplastics and the nozzles are typically greater than 100°C, and they are not compatible with the support media consisting of microparticulate hydrogels.
Researchers from the Singapore University of Technology and Design's (SUTD) Soft Fluidics Lab developed a simple method to 3D print thermoplastics using embedded media in freeform manners, termed freeform polymer precipitation (FPP).
In FPP, microparticulate gels as surrounding media simultaneously offered two essential functions. The microparticulate gels provided structural support to the printed ink and induced the phase change of the printed ink via immersion precipitation. 3D printing based on immersion precipitation with surrounding microparticulate has unlocked the capability of freeform fabrication of thermoplastics.
The study demonstrated the use of both water-based and ethanol-based microparticulate gels as surrounding gels that allowed the increased numbers of solvents and polymers to be used in FPP. Polymer inks with low polymer concentrations (with low viscosity) and inks with pore-inducing agents conferred internal porosity to the printed structures.
"Our approach has overcome the limitation of use of microparticulate media for the fabrication of freeform structures of thermoplastics, for the first time, using the immersion precipitation of polymer inks in microparticulate gels," said the lead author of the paper Dr Rahul Karyappa from SUTD.
"FPP offers a unique way to fabricate mechanically strong components consisting of thermoplastics in various 3D shapes without support materials. This expands the available technologies of additive manufacturing," added principal investigator, Associate Professor Michinao Hashimoto from SUTD.
INFORMATION:
This paper titled 'Freeform Polymer Precipitation in Microparticulate Gels' has been published in ACS Applied Polymer Materials, a leading journal that encourages original research covering all aspects of engineering, chemistry, physics, and biology relevant to applications of polymers.
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-04-08
Researchers from the University of Hawai'i (UH) at Mānoa, University of British Columbia (UBC), San Diego State University (SDSU), and elsewhere have created 3D molecular maps of bacteria, viruses, and biochemicals across coral colonies along with their interacting organisms such as algae and other competing corals. This allowed the team to discover specific microbial and viral functions that appear to be key components of the coral microbiome.
The study, published recently in Frontiers of Marine Science, used a novel combination of state-of-the-art molecular methods with cutting-edge 3D imaging techniques to create high-resolution molecular maps on coral reef organisms.
Healthy coral reefs ...
2021-04-08
Forecasts aren't just for the weather. Scientists can use weather radar and related technology to chart the journeys of billions of migratory birds, which can help protect these global travelers from a growing array of threats.
In a new breakthrough on this front, a team led by Colorado State University used millions of observations from 143 weather surveillance radars to evaluate a forecasting system for nocturnal bird migration in the United States.
Using these tools, the team discovered that a mere 10 nights of action are required to reduce risk to 50% of avian migrants passing over a ...
2021-04-08
LOS ALAMOS, N.M., April 6, 2021--In the vast Colorado River basin, climate change is driving extreme, interconnected events among earth-system elements such as weather and water. These events are becoming both more frequent and more intense and are best studied together, rather than in isolation, according to new research.
"We found that concurrent extreme hydroclimate events, such as high temperatures and unseasonable rain that quickly melt mountain snowpack to cause downstream floods, are projected to increase and intensify within several critical regions of the Colorado ...
2021-04-08
Okazaki, Japan -mm dd, 2021--Many people with Parkinson's disease develop abnormal movements called L-DOPA induced dyskinesia, a major side effect of long-term medication. The mechanism underlying this side effect has been unknown. In this study, researchers have revealed relation between changes of neuronal activities and dyskinesia.
Parkinson's disease (PD) is the common age-related neurological disorder affecting 7 - 10 million people worldwide. It is caused by loss of dopaminergic neurons in the brain region called the substantia nigra, and induces difficulty in execution of movements (akinesia), muscle stiffness (rigidity), walking difficulty, tremorous hand movements ...
2021-04-08
Details:
According to a linguistic survey report, people often confuse the pronunciation of /hi/ with that of /si/ in the dialect of Tokyo and the Tohoku region of Japan. A team of researchers at Toyohashi University of Technology and the National Institute for Japanese Language and Linguistics (NINJAL) found that the confusion is resulted from the articulation of the tongue varying in the transverse direction while the tongue tip is positioned at the same place of articulation. The study was published online in the Journal of the Acoustical Society of America on April 7, 2021.
In the Japanese language, the consonant /s/ followed by vowel /i/ is distinct ...
2021-04-08
Osaka, Japan - Catalysts are crucial to making industrial processes viable. However, many of the non-precious metal catalysts used for synthesis have low activity, are difficult to handle, and/or require harsh reaction conditions. Osaka University researchers have developed a single-crystal cobalt phosphide nanorod catalyst that overcomes several of the limitations of conventional cobalt catalysts. Their findings were published in JACS Au.
Reductive amination is an important chemical reaction that is used to convert carbonyl compounds into amines. It is a key step in the production of many materials such as polymers, dyes, and pharmaceuticals, and is attractive because the reagents are cost effective and widely available, ...
2021-04-08
An adaptive cognitive training program could help treat attention and working memory difficulties in children with sickle cell disease (SCD), a new study published in the of Journal of Pediatric Psychology shows.
These neurocognitive difficulties have practical implications for the 100,000 individuals in the U.S. with SCD, as 20-40% of youth with SCD repeat a grade in school and fewer than half of adults with SCD are employed. Interventions to prevent and treat neurocognitive difficulties caused by SCD have the potential to significantly improve academic outcomes, vocational attainment and quality of life.
The study, led by Steven Hardy, Ph.D., director of Psychology and Patient Care Services at the Center for Cancer and Blood Disorders at Children's ...
2021-04-08
Extremely structured electromagnetic pulse carries not only the ultimate human dream of ultra-fast and ultra-intense energy extraction but also numerous extraordinary fundamental physical effects. As a traditional viewpoint, Electromagnetic pulses are typically treated as space-time (or space-frequency) separable solutions of Maxwell's equations, where spatial and temporal (spectral) dependence can be treated separately. However, recent advances in structured light and topological optics have highlighted the nontrivial wave-matter interactions of pulses with complex space-time separability (STNS), as well as their potential for energy and information transfer.
Recently, a research ...
2021-04-08
Stem cell research has allowed medicine to go places that were once science fiction. Using stem cells, scientists have manufactured heart cells, brain cells and other cell types that they are now transplanting into patients as a form of cell therapy. Eventually, the field anticipates the same will be possible with organs. A new paper written by a group of international researchers led by Tsutomu Sawai, an assistant professor at the Kyoto University Institute for the Advanced Study of Human Biology (ASHBi) and the Center for iPS Cell Research and Application (CiRA), explains the future ethical implications of this research ...
2021-04-08
Travel and economic slowdowns due to the COVID-19 pandemic combined to put the brakes on shipping, seafloor exploration, and many other human activities in the ocean, creating a unique moment to begin a time-series study of the impacts of sound on marine life.
A community of scientists has identified more than 200 non-military ocean hydrophones worldwide and hopes to make the most of the unprecedented opportunity to pool their recorded data into the 2020 quiet ocean assessment and to help monitor the ocean soundscape long into the future. They aim for a total of 500 hydrophones capturing the signals of whales and other marine life while assessing the racket levels of human activity. ...
LAST 30 PRESS RELEASES:
[Press-News.org] Unique method to fabricate freeform structures of thermoplastics in microparticulate gels
3D printing of polymer inks in embedding media to fabricate freeform and overhang structures may find applications in rapid prototyping of actuators and antennas
