Fractured artificial rock helps crack a 54-year-old mystery

by Adam Hadhazy, Princeton University

Princeton researchers have developed a technique to better understand how polymers 

flow through small channels under pressure. Credit: David Kelly Crow

Princeton researchers have solved a 54-year-old puzzle about why certain fluids strangely slow down under pressure when flowing through porous materials, such as soils and sedimentary rocks. The findings could help improve many important processes in energy, environmental and industrial sectors, from oil recovery to groundwater remediation.

The fluids in question are called polymer solutions. These solutions—everyday examples of which include cosmetic creams and the mucus in our noses—contain dissolved polymers, or materials made of large molecules with many repeating subunits. Typically, when they're put under pressure, polymer solutions become less viscous and flow faster. But when going through materials with lots of tiny holes and channels, the solutions tend to become more viscous and gunky, reducing their flow rates.

To get at the root of the problem, the Princeton researchers devised an innovative experiment using a see-through porous medium made of tiny glass beads—a transparent artificial rock. This lucid medium allowed the researchers to visualize a polymer solution's movement. The experiment revealed that the long-baffling increase in viscosity in porous media happens because the polymer solution's flow becomes chaotic, much like turbulent air on an airplane ride, swirling into itself and gumming up the works.

"Surprisingly, until now, it has not been possible to predict the viscosity of polymer solutions flowing in porous media," said Sujit Datta, an assistant professor of chemical and biological engineering at Princeton and senior author of the study appearing Nov. 5 in the journal Science Advances. "But in this paper, we've now finally shown these predictions can be made, so we've found an answer to a problem that has eluded researchers for over a half-century."

"With this study, we finally made it possible to see exactly what is happening underground or within other opaque, porous media when polymer solutions are being pumped through," said Christopher Browne, a Ph.D. student in Datta's lab and the paper's lead author.

Browne ran the experiments and built the experimental apparatus, a small rectangular chamber randomly packed with tiny borosilicate glass beads. The setup, akin to an artificial sedimentary rock, spanned only about half the length of a pinky finger. Into this faux rock, Browne pumped a common polymer solution laced with fluorescent latex microparticles to help see the solution's flow around the beads. The researchers formulated the polymer solution so the material's refractive index offset light distortion from the beads and made the whole setup transparent when saturated. Datta's lab has innovatively used this technique to create see-through soil for studying ways to counter agricultural droughts, among other investigations.

Browne then zoomed in with a microscope on the pores, or holes between the beads, which occur on the scale of 100 micrometers (millionths of a meter) in size, or similar to the width of a human hair, in order to examine the fluid flow through each pore. As the polymer solution worked its way through the porous medium, the fluid's flow became chaotic, with the fluid crashing back into itself and generating turbulence. What's surprising is that, typically, fluid flows at these speeds and in such tight pores are not turbulent, but "laminar": the fluid moves smoothly and steadily. As the polymers navigated the pore space, however, they stretched out, generating forces that accumulated and generated turbulent flow in different pores. This effect grew more pronounced when pushing the solution through at higher pressures.

"I was able to see and record all these patchy regions of instability, and these regions really impact the transport of the solution through the medium," said Browne.

Princeton researchers have developed a technique to better understand how polymers flow through small channels under pressure. Credit: David Kelly Crow

The Princeton researchers used data gathered from the experiment to formulate a way to predict the behavior of polymer solutions in real-life situations.

Gareth McKinley, a professor of mechanical engineering at the Massachusetts Institute of Technology who was not involved in the study, offered comments on its significance.

"This study shows definitively that the large increase in the macroscopically observable pressure drop across a porous medium has its microscopic physical origins in viscoelastic flow instabilities that occur on the pore scale of the porous medium," McKinley said.

Given that viscosity is one of the most fundamental descriptors of fluid flow, the findings not only help deepen understanding of polymer solution flows and chaotic flows in general, but also provide quantitative guidelines to inform their applications at large scales in the field.

"The new insights we have generated could help practitioners in diverse settings determine how to formulate the right polymer solution and use the right pressures needed to carry out the task at hand," said Datta. "We're particularly excited about the findings' application in groundwater remediation."

Because polymer solutions are inherently goopy, environmental engineers inject the solutions into the ground at highly contaminated sites such as abandoned chemical factories and industrial plants. The viscous solutions help push out trace contaminants from the affected soils. Polymer solutions likewise aid in oil recovery by pushing oil out of the pores in underground rocks. On the remediation side, polymer solutions enable "pump and treat," a common method for cleaning up groundwater polluted with industrial chemicals and metals that involves bringing the water to a surface treatment station. "All these applications of polymer solutions, and more, such as in separations and manufacturing processes, stand to benefit from our findings," said Datta.

Overall, the new findings on polymer solution flow rates in porous media brought together ideas from multiple fields of scientific inquiry, ultimately disentangling what had started out as a long-frustrating, complex problem.

"This work draws connections between studies of polymer physics, turbulence, and geoscience, following the flow of fluids in rocks underground as well as through aquifers," said Datta. "It's a lot of fun sitting at the interface between all these different disciplines."

Tiny polymer springs give a boost to environmental cleanup

More information: Christopher A. Browne et al, Elastic turbulence generates anomalous flow resistance in porous media, Science Advances (2021). DOI: 10.1126/sciadv.abj2619. www.science.org/doi/10.1126/sciadv.abj2619

Journal information: Science Advances 

Provided by Princeton University 

 

Closed loop for circular economy: New polymer recycling strategy ensures both high stability and complete recyclability

by Shinshu University

In a new study, researchers from Japan proposed a new recycling strategy that facilitates

 material recycling without any loss in their properties. In “closed-loop” recycling, a polymer 

film composed of polyacrylate-based microparticles is disassembled into individual 

microparticles, which can be reassembled to form the film without losing any properties.

 This process could also be applied to recycle polymer microparticles in composite 

materials. Credit: Daisuke Suzuki from Shinshu University

The ever-increasing generation of plastic solid waste has resulted in global plastic pollution both on land and in the oceans. Projections show that plastic waste will double in the next 20 years, causing further environmental problems. Large amounts of plastic waste are, at present, incinerated or deposited in landfills. This not only degrades the environment but also depletes valuable resources.

In this light, recycling plastics such as polymers is a promising sustainable alternative for waste management. But this involves the breaking of chemical bonds between monomers (building blocks of polymers), which diminishes their overall stability and quality. Addressing this concern, researchers have developed methods to recycle polymers in a "closed loop," that is, without the loss of these properties. However, these methods are complicated and expensive and require specialized monomers, necessitating further innovation.

In this direction, a group of researchers led by Daisuke Suzuki, an Associate Professor at Shinshu University, has recently proposed a closed-loop recycling process based on polymer microparticles. Their work, co-authored by Dr. Takumi Watanabe and Dr. Haruka Minato of Shinshu University, has been published in Green Chemistry.

Prof. Suzuki briefly explains the rationale behind their strategy: "Recycling materials without deterioration (closed-loop recycling) is attractive in terms of reducing anthropogenic waste. However, this currently remains very difficult given that there usually is a trade-off between mechanical stability and degradability of polymer materials."

"Our material recycling concept with microparticles enables the recycling of a huge amount of functional polymer materials that we use in our day-to-day lives and has the potential to solve the problems of resource depletion and environmental pollution."

In their study, the authors prepared polymer microparticles via the aqueous emulsion polymerization of methyl acrylate (MA) monomers in water, which resulted in polymer chains. These aggregated to form a solution containing uniform spherical poly-MA microparticles. The solution was then dried to get a thin polymer film with physical (as opposed to chemical) cross-linking among the microparticles, which could be reobtained by dissolving the film in ethanol. These recycled microparticles, in turn, could be reused to form various recycled materials.

The films synthesized in this work exhibit several desirable properties, which they retain upon recycling. They have high mechanical stability and fracture energy, which is an indicator of their toughness. The latter property increases with the interfacial thickness between the poly-MA microparticles. This, in turn, decreases with the degree of interparticle cross-linking but increases upon heating the film.

The researchers further enhanced the fracture energy of the polymer films by mixing the microparticles with silica nanofillers. Moreover, adding colored pigments gave the resulting composite films tunable optical properties, which did not diminish upon recycling. These results suggest that closed-loop recycling based on polymer microparticles will enable resource circulation for polymers as well as numerous other composite materials that contain polymer microparticles to create adhering interfaces between their different layers.

Prof. Suzuki says, "Our concept can lead to the production of fully recyclable films with high fracture energy. Therefore, it will enable the recycling of huge amounts of various polymer materials, thus reducing plastic waste and potentially solving the problems of environmental degradation and plastic pollution."

The "closed"-loop recycling strategy certainly "opens" new doors for the efficient and sustainable recycling of polymer materials!

More information: Takumi Watanabe et al, Closed-loop recycling of microparticle-based polymers, Green Chemistry (2023). DOI: 10.1039/D3GC00090G

Journal information: Green Chemistry 

Provided by Shinshu UniversityTechnology transforms plastic waste bottles into polymers for lithium-ion batteries

 

Stay focused: Algae-inspired polymers light the way for enhanced night vision

Researchers from the University of Tsukuba synthesize an elastic polymer from low-cost, sustainable materials, that can be used it to fabricate lenses that help keep infrared cameras focused in the dark

UNIVERSITY OF TSUKUBA

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CREDIT: UNIVERSITY OF TSUKUBA

Tsukuba, Japan - In a study recently published in ACS Applied Polymer Materials, researchers from the University of Tsukaba synthesized an infrared-transmitting polymer--based on low-cost, widely available materials--that retains its shape after stretching. The properties of this polymer are highly applicable to the preparation of cheaper night-vision lenses that retain focus while imaging at variable distances.

Cameras that function in the dark are common in many fields, including the military, security, firefighting, and wildlife tracking. However, infrared night-vision lenses are typically expensive, and the camera images tend to appear flat. Consequently, there is a need for lenses based on commonly available, cheap materials that are useful for more realistic vision in three dimensions.

The researchers' polymer is based on sulfur and compounds derived from algae and plants. The polymer is easy to prepare using a chemical process called inverse vulcanization: simply mix the constituent compounds together and stir while heating. As a first step, the researchers designed a polymer that is elastic--that is, reverts to its original shape--after being repeatedly restretched by 20%.

"Inverse vulcanization is an ideal synthetic approach for our polymers," explains lead author Professor Junpei Kuwabara. "Squalene and other long unsaturated hydrocarbons help optimize the cross-linking structure and give the polymers a desirable elasticity."

Next, the researchers needed to determine whether lenses constructed from their polymers are at least partially transparent to infrared light, for nighttime imaging. Lens construction was easy: simply pour the polymer into a lens-shaped silicone mold and heat for a few hours. Even a 3.3-millimeter-thick lens transmitted 10% of incoming infrared light.

"The lenses have two wavelength ranges that are infrared-transparent," says senior author Professor Takaki Kanbara. "No lens is completely transparent; 10% transmission is an excellent value for these materials."

Furthermore, the researchers confirmed that the polymer has variable-focus properties. By projecting an image through the lens, and monitoring the resulting image that came through while elongating the lens, much of the transmitted image remained in focus.

"The lens retained 54% of the focus variation, which is sufficient for practical uses," explains Dr. Takashi Fukuda, senior researcher, National Institute of Advanced Industrial Science and Technology (AIST). "The lens also retained its full initial focus after contracting back to its original shape."

The fabrication of conventional infrared night-vision lenses, in a way that allows users to easily change focus from one position to another, is typically difficult. Without a variable-focus capability, details that are pertinent to criminal or research investigations, for example, may be lost. The researchers of this study are overcoming current lens design limitations by using cheap, sustainable materials, and fabrication procecures that any researcher can carry out in their laboratory. Development of new materials in this area may benefit a range of sectors including emergency personnel and environmental researchers

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The article, "Algae-inspired, sulfur-based polymer with infrared transmission and elastic function," was published in ACS Applied Polymer Materials at DOI: 10.1021/acsapm.0c00924.

 

Using CO2 and biomass, FAMU-FSU researchers find path to more environmentally friendly recyclable plastics

FLORIDA STATE UNIVERSITY

 

IMAGE: 

FROM LEFT, ASSOCIATE PROFESSOR HOYONG CHUNG AND POSTDOCTORAL RESEARCHER ARIJIT GHORAI DISPLAY THE TWO PHASES OF THEIR DEGRADABLE POLYMER AT THE DITTMER CHEMISTRY LAB AT FLORIDA STATE UNIVERSITY.

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CREDIT: SCOTT HOLSTEIN/FAMU-FSU COLLEGE OF ENGINEERING

Modern life relies on plastic. This lightweight, adaptable product is a cornerstone of packaging, medical equipment, the aerospace and automotive industries and more. But plastic waste remains a problem as it degrades in landfills and pollutes oceans.

FAMU-FSU College of Engineering researchers have created a potential alternative to traditional petroleum-based plastic that is made from carbon dioxide (CO2) and lignin, a component of wood that is a low-cost byproduct of paper manufacturing and biofuel production. Their research was published in Advanced Functional Materials.

“Our study takes the harmful greenhouse gas CO2 and makes it into a useful raw material to produce degradable polymers or plastics,” said Hoyong Chung, an associate professor in chemical and biomedical engineering at the college. “We are not only reducing CO2 emissions, but we are producing a sustainable polymer product using the CO2.”

This study is the first to demonstrate the direct synthesis of what’s known as a cyclic carbonate monomer — a molecule made of carbon and oxygen atoms that can be linked with other molecules — made from CO2 and lignin.

By linking multiple monomers together, scientists can create synthetic polymers, long-chained molecules that can be designed to fill all manner of applications.

The material developed by Chung and his research team is fully degradable at the end of its life without producing microplastics and toxic substances. It can be synthesized at lower pressures and temperatures. And the polymer can be recycled without losing its original properties.

Using depolymerization, the researchers can convert polymers to pure monomers, which are the building blocks of polymers. This is the key to the high quality of the recycled material. The monomers can be recycled indefinitely and produce a high-quality polymer as good as the original, an improvement over previously developed and currently used polymer materials in which repeated heat exposure from melting reduces quality and allows for limited recycling.

“We can readily degrade the polymer via depolymerization, and the degraded product can synthesize the same polymer again,” Chung said. “This is more cost effective and keeps it from losing original properties of polymers over multiple recycling. This is considered a breakthrough in material science, as it enables the realization of a true circular economy.”

The newly developed material could be used for low-cost, short lifespan plastic products in such sectors as construction, agriculture, packaging, cosmetics, textiles, diapers and disposable kitchenware. With further development, Chung anticipates its use in highly specialized polymers for biomedical and energy storage applications.

The FSU Office of Commercialization provided valuable foundational support for Chung’s research. Support from an internal funding program helped previous work with lignin-based polymers, and with the help of the office, he has received patents for other polymer research.

The project was supported by federal funds awarded to the State of Florida from the United States Department of Agriculture, National Institute of Food and Agriculture and support from the FAMU-FSU College of Engineering. Postdoctoral researcher Arijit Ghorai was the lead author of the study.

A closer view of the polymer developed by Chung’s research team in monomer and polymer phases.

CREDIT

Scott Holstein/FAMU-FSU College of Engineering

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JOURNAL

Advanced Functional Materials

DOI

10.1002/adfm.202403035 

ARTICLE TITLE

CO2 and Lignin-Based Sustainable Polymers with Closed-Loop Chemical Recycling

 

Alternatives in car and aircraft construction: New joining and additive manufacturing processes allow adhesive-free joining of wood and metal

Using 3D printing technology and ultrasonic joining technique, researchers at Graz University of Technology succeeded in attaining an extremely strong joining of the renewable raw material wood with metal and polymer composite.

Graz University of Technology

 

image: 

In Ultrasonic Joining, wood and the base component are joined by frictional heat.

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Credit: Wolf - TU Graz

The renewable raw material wood is climate-neutral and at the same time light and strong, making it fundamentally attractive for use in vehicle manufacturing. One challenge to date has been joining the wood and the other materials in the vehicle, such as metals and polymer composites, in a robust way. The research team led by Sergio Amancio from the Institute of Materials Science, Joining and Forming of Graz University of Technology (TU Graz) - Gean Marcatto, Awais Awan, Willian Carvalho and Stefan Herbst - has now successfully tested two techniques by which extremely strong joints can be achieved without using adhesives or screws. The application of the techniques to wood is patent pending and could be used in the aircraft, automotive and furniture industries.

Joining technology and additive manufacturing enable wood to replace less sustainable materials

The two novel manufacturing techniques are suitable for their own areas of application. Beech, oak, carbon fibre-reinforced polyamide and polyphenylene sulphide, stainless steel 316L, and Ti-64 alloys, were used as test materials. “Our motivation is clearly environmental protection,” says Sergio Amancio. With new manufacturing processes, the renewable raw material wood could replace components made from energy-intensive or difficult-to-recycle materials.

AddJoining: 3D printing leads to joining via the wood pores

With the AddJoining technique, a component made of polymer composite is affixed to and printed directly onto a surface – in this case wood – using a 3D printing process. The printed material penetrates into the wood pores, where a chemical reaction occurs, similar to the reaction of glue with wood. The resulting connections were highly successful in mechanical load tests. “After the joint fractured, we were able to find polymer in the wood pores and broken wood fibres in the polymer, which suggests that the fracture occurred in the wood and polymer, but not at the joint,” explains Gean Marcatto, who works on this process as a postdoc at the institute. These successful tests were carried out on the untreated wood surface. Even more durable joints could be achieved by introducing a micro- or nano-structure into the wood through laser texturing or etching, which increases the pores and enhances the bonding surfaces. “But we wanted to work with as few steps as possible and, above all, without chemicals,” says Sergio Amancio, explaining the underlying idea. “We can use this technology particularly well with complicated 3D geometries because the components are printed directly onto the surface – in whatever geometry is required.”

Ultrasonic joining ensures a stable spot joint

In Ultrasonic Joining, high-frequency vibration with low amplitude is applied to the wooden component using a sonotrode. In contact with the base component – in this case, polymer or a polymer composite material – the friction generates heat at the interface which melts the surface of the polymer part. Molten polymer infiltrates into the naturally porous surface of the wood. In this way, a very stable spot joint can be achieved, from a mixture of mechanical interlocking (because the melted plastic solidifies again in the wood) and adhesion forces. “This technique is particularly suitable for large components and 2D structures since we achieve a precisely localized spot joint,” explains Awais Awan, who dedicated his doctorate to joining technology using ultrasonic energy. These spot joints were also mechanically tested with great success. The joints could also be further strengthened by pre-treatment of the wood surface such as laser texturing.

In future, the team would like to work with partners from the automotive, aircraft and furniture industries to further refine the technologies.

This research area is anchored in the Field of Expertise Advanced Materials Science, one of five strategic focus areas of TU Graz.

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Method of Research

Experimental study

Addjoining uses 3D printing to print a component made of plastic composites onto wood.

Credit

Wolf - TU Graz

 

New technology uses light to engrave erasable 3D images

Study: Chemical "switch" and projector make any polymer a reusable 3D canvas

Peer-Reviewed Publication

Dartmouth College

 

image: 

A two-dimensional light engraving (left) suspended in a polymer film. The original photo (right) was projected into the film using a red- and blue-light projector that activates a photosensitive additive in the polymer. Applying heat to the film will erase the image and make it ready to use again.

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Credit: Ivan Aprahamian/Sara Patch

Imagine if physicians could capture three-dimensional projections of medical scans, suspending them inside an acrylic cube to create a hand-held reproduction of a patient's heart, brain, kidneys, or other organs. Then, when the visit is done, a quick blast of heat erases the projection and the cube is ready for the next scan.

A new report in the journal Chem by researchers at Dartmouth and Southern Methodist University (SMU) outlines a technical breakthrough that could enable such scenarios, and others with widespread utility.

The study introduces a technique that uses a specialized light projector to imprint two-dimensional and 3D images inside any polymer that contains a photosensitive chemical additive the team developed. The light-based engraving remains in the polymer until heat is applied, which erases the image and makes it ready to use again.

In short, the researchers write with light and erase with heat or light, says Ivan Aprahamian, professor and chair of chemistry at Dartmouth and co-corresponding author on the paper. In test trials, the researchers produced high-resolution images in polymers ranging from thin films to six inches thick.

The technology is intended for any situation where having detailed, precise visual data in a compact and easily customizable format could be critical, Aprahamian says, such as planning surgeries and developing architectural designs. The device also could be used for generating 3D images for education and even creating art, he says.

"This is like 3D printing that is reversible," Aprahamian says. "You can take any polymer that has the optimal optic properties—that is, it's translucent—and enhance it with our chemical switch. Now that polymer is a 3D display. You do not need virtual reality headsets or complicated instrumentation. All you need is the right piece of plastic and our technology."

Readily available polymers—such as an acrylic cube—could be transformed into a display with the addition of the light-sensitive chemical "switch" formulated by Aprahamian and Qingkai Qi, a postdoctoral researcher at Dartmouth and the study's first author. The switch consists of a compound called azobenzene that reacts to light paired with boron difluoride, which enhances the switch's optical properties.

Once integrated with a polymer, the switch reacts to wavelengths of red and blue light beamed from a projector developed in the lab of Alex Lippert, professor of chemistry at SMU and co-corresponding author of the study. Study co-author Joshua Plank is a PhD candidate in Lippert's lab. The red light acts like ink by activating the chemical additive to create the image, Aprahamian says. Blue light can then be used to erase it.

The projector illuminates the treated polymer from different angles with various patterns of light, Lippert explains. The photosensitive chemical developed in Aprahamian's lab at Dartmouth is activated where these patterns intersect to produce 3D patterns. Creating 3D projections from 2D images such as a chest X-ray would mean projecting slices of the original image into a polymer cube or other shape until the slices combine to form the full 3D image, Lippert says.

The researchers have been able to produce animated images in polymers and future work revolves around improving that process. In the meantime, the technology reported in Chem could be developed for practical use in its current form, such as for industry or health care.

"Scaling up requires tuning the chemical switch properties to improve resolution, contrast, and refresh rate," Lippert says. "The projector system can in principle be scaled up and developed into a turnkey system with automated hardware and associated software for easy us

Animated cat [VIDEO] |

The reseachers are able to produce light-based three-dimensional and animated images in polymers ranging from thin films to six inches thick. They project slices of original two-dimensional images until the slices combine to form a full 3D or animated image. Future work revolves around improving the process for creating animated images.

Credit

Ivan Aprahamian

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Journal

Chem

DOI

10.1016/j.chempr.2024.07.012 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

A Photoswitchable Hand-Held Volumetric 3D Display

Article Publication Date

9-Aug-2024

3D laser printing with bioinks from microalgae

Heidelberg researchers successfully develop a new generation of biocompatible materials for additive manufacturing

Heidelberg University

Microalgae such as the diatom Odontella aurita and the green alga Tetraselmis striata are especially suitable as “biofactories” for the production of sustainable materials for 3D laser printing due to their high content in lipids and photoactive pigments. An international research team led by Prof. Dr Eva Blasco, a scientist at the Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM) of Heidelberg University, has succeeded for the first time in manufacturing inks for printing complex biocompatible 3D microstructures from the raw materials extracted from the microalgae. The microalgae-based materials could be used in future as the basis for implants or scaffolds for 3D cell cultures.

Among the additive manufacturing techniques, two-photon 3D laser printing offers particular advantages for manufacturing at the micro- and nanoscale. Owing to its remarkable resolution, it finds application in numerous fields including optics and photonics, microfluidics, and biomedicine. The process involves focusing a laser beam on a liquid, photoreactive resin, a so-called “ink”. At the focal point, the laser light activates special molecules known as photoinitiators and triggers a chemical reaction, causing local solidification of the ink.

To date, petrochemical-based polymers have been mainly used as inks for this highly precise 3D laser printing process. However, these polymers contribute to the depletion of fossil fuels and the emission of greenhouse gases and can also contain toxic components, as Prof. Blasco points out. Microalgae are particularly well suited as “biofactories” for the production of sustainable materials for 3D printing due to their rapid growth rate, CO2-fixation during cultivation, and biocompatibility. “Despite their advantages, microalgae have hardly been considered as raw materials for light-based 3D printing,” says Prof. Blasco, whose group conducts research at the interface of macromolecular chemistry, materials science, and 3D nanofabrication.

The research team succeeded for the first time in extracting biocompatible materials for high-resolution 3D laser printing from microalgae. For their experiments, the researchers selected two species – the diatom Odontella aurita and the green alga Tetraselmis striata – that contain particularly high levels of lipids in the form of triglycerides. The team extracted the triglycerides and functionalized them with acrylates to facilitate rapid curing under light irradiation. The photoactive green pigments present in the microalgae proved to be suitable as photoinitiators. When exposed to light, they trigger the chemical reaction that solidifies the ink into a three-dimensional structure. “In this way we avoid using potentially toxic additives like the photoinitiators used in conventional inks,” explains first author Clara Vazquez-Martel, a doctoral candidate in Eva Blasco’s research team at IMSEAM.

Using the new ink system, the researchers were able to produce different 3D microstructures with high precision, exhibiting complex features such as overhanging roofs and cavities. Using cell culture experiments, the researchers also investigated the biocompatibility of the microalgae-based inks. They prepared 3D microscaffolds on which the cells were cultured for about 24 hours. They observed a survival rate of almost 100 percent. “Our results open up new possibilities not only for more sustainable 3D printing with light, but also for life science applications – from 3D cell cultures to biocompatible implants,” says Prof. Blasco.

The research was conducted within the Cluster of Excellence “3D Matter Made to Order”, a collaboration of Heidelberg University and the Karlsruhe Institute of Technology (KIT). This study involved researchers from Heidelberg, the KIT, and the Spanish Bank of Algae at the University of Las Palmas de Gran Canaria (ULPGC, Spain). The work was funded by the German Research Foundation, the Carl Zeiss Foundation, the Fonds der Chemischen Industrie, and the European Union in the framework of the European Territorial Cooperation Program. The research has been published in the journal “Advanced Materials”.

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Journal

Advanced Materials

DOI

10.1002/adma.202402786 

Article Title

Microalgae-Based Materials for 3D Printing with Light. Advanced Materials