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Toward customizable timber, grown in a lab – EurekAlert

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image: In an effort to provide an environmentally friendly and low-waste alternative, researchers at MIT have pioneered a tunable technique to generate wood-like plant material in a lab.
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Credit: Image courtesy of Luis Fernando Velásquez-García, Ashley Beckwith, et al

Each year, the world loses about 10 million hectares of forest — an area about the size of Iceland — because of deforestation. At that rate, some scientists predict the world’s forests could disappear in 100 to 200 years.

In an effort to provide an environmentally friendly and low-waste alternative, researchers at MIT have pioneered a tunable technique to generate wood-like plant material in a lab, which could enable someone to “grow” a wooden product like a table without needing to cut down trees, process lumber, etc.

These researchers have now demonstrated that, by adjusting certain chemicals used during the growth process, they can precisely control the physical and mechanical properties of the resulting plant material, such as its stiffness and density.

They also show that, using 3D bioprinting techniques, they can grow plant material in shapes, sizes, and forms that are not found in nature and that can’t be easily produced using traditional agricultural methods.

“The idea is that you can grow these plant materials in exactly the shape that you need, so you don’t need to do any subtractive manufacturing after the fact, which reduces the amount of energy and waste. There is a lot of potential to expand this and grow three-dimensional structures,” says lead author Ashley Beckwith, a recent PhD graduate.

Though still in its early days, this research demonstrates that lab-grown plant materials can be tuned to have specific characteristics, which could someday enable researchers to grow wood products with the exact features needed for a particular application, like high strength to support the walls of a house or certain thermal properties to more efficiently heat a room, explains senior author Luis Fernando Velásquez-García, a principal scientist in MIT’s Microsystems Technology Laboratories.

Joining Beckwith and Velásquez-García on the paper is Jeffrey Borenstein, a biomedical engineer and group leader at the Charles Stark Draper Laboratory. The research is published today in Materials Today.

Planting cells

To begin the process of growing plant material in the lab, the researchers first isolate cells from the leaves of young Zinnia elegans plants. The cells are cultured in liquid medium for two days, then transferred to a gel-based medium, which contains nutrients and two different hormones.

Adjusting the hormone levels at this stage in the process enables researchers to tune the physical and mechanical properties of the plant cells that grow in that nutrient-rich broth.

“In the human body, you have hormones that determine how your cells develop and how certain traits emerge. In the same way, by changing the hormone concentrations in the nutrient broth, the plant cells respond differently. Just by manipulating these tiny chemical quantities, we can elicit pretty dramatic changes in terms of the physical outcomes,” Beckwith says.

In a way, these growing plant cells behave almost like stem cells — researchers can give them cues to tell them what to become, Velásquez-García adds.

They use a 3D printer to extrude the cell culture gel solution into a specific structure in a petri dish, and let it incubate in the dark for three months. Even with this incubation period, the researchers’ process is about two orders of magnitude faster than the time it takes for a tree to grow to maturity, Velásquez-García says.

Following incubation, the resulting cell-based material is dehydrated, and then the researchers evaluate its properties.

Wood-like characteristics

They found that lower hormone levels yielded plant materials with more rounded, open cells that have lower density, while higher hormone levels led to the growth of plant materials with smaller, denser cell structures. Higher hormone levels also yielded plant material that was stiffer; the researchers were able to grow plant material with a storage modulus (stiffness) similar to that of some natural woods.

Another goal of this work is to study what is known as lignification in these lab-grown plant materials. Lignin is a polymer that is deposited in the cell walls of plants which makes them rigid and woody. They found that higher hormone levels in the growth medium causes more lignification, which would lead to plant material with more wood-like properties.

The researchers also demonstrated that, using a 3D bioprinting process, the plant material can be grown in a custom shape and size. Rather than using a mold, the process involves the use of a customizable computer-aided design file that is fed to a 3D bioprinter, which deposits the cell gel culture into a specific shape. For instance, they were able to grow plant material in the shape of a tiny evergreen tree.

Research of this kind is relatively new, Borenstein says.

“This work demonstrates the power that a technology at the interface between engineering and biology can bring to bear on an environmental challenge, leveraging advances originally developed for health care applications,” he adds.

The researchers also show that the cell cultures can survive and continue to grow for months after printing, and that using a thicker gel to produce thicker plant material structures does not impact the survival rate of the lab-grown cells.

“Amenable to customization”

“I think the real opportunity here is to be optimal with what you use and how you use it. If you want to create an object that is going to serve some purpose, there are mechanical expectations to consider. This process is really amenable to customization,” Velásquez-García says.

Now that they have demonstrated the effective tunability of this technique, the researchers want to continue experimenting so they can better understand and control cellular development. They also want to explore how other chemical and genetic factors can direct the growth of the cells.

They hope to evaluate how their method could be transferred to a new species. Zinnia plants don’t produce wood, but if this method were used to make a commercially important tree species, like pine, the process would need to be tailored to that species, Velásquez-García says.  

Ultimately, he is hopeful this work can help to motivate other groups to dive into this area of research to help reduce deforestation.

“Trees and forests are an amazing tool for helping us manage climate change, so being as strategic as we can with these resources will be a societal necessity going forward,” Beckwith adds.

This research is funded, in part, by the Draper Scholars Program.

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Written by Adam Zewe, MIT News Office

Additional background

Paper: “Physical, mechanical, and microstructural characterization of novel, 3D-printable, tunable, lab-grown plant materials generated from Zinnia elegans cell cultures”

https://www.sciencedirect.com/science/article/pii/S1369702122000451


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My Thesis in 400 Words: Anne Boucher | Institute for Research on Exoplanets – News | Institute for Research on Exoplanets

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Anne Boucher, an iREx student at the Université de Montréal, submitted her doctoral thesis at the end of 2021. She summarises the research project she carried out as part of her Ph.D here.

During my Ph.D, I became interested in the atmosphere of gas giant exoplanets that orbit very close to their star. Thanks to a technique called transmission spectroscopy, I studied the chemical composition of their atmosphere, which gives a lot of information on their formation and evolution mechanisms. The detailed study of these exoplanets, which we sometimes call hot Jupiters or hot sub-Saturns, provides a better understanding of the physical, chemical, and dynamical processes that govern the atmosphere of these celestial objects.

I mainly used data from the SPIRou instrument, a high-resolution spectropolarimeter that operates in the near infrared and is installed at the Canada-France-Hawaii Telescope. We first observed HD 189733 b, one of the most studied exoplanets, to build the analysis codes. By exploiting transit spectroscopy, we were able to confirm the presence of water and determine its abundance. The results obtained, consistent with previous studies, indicate that the atmosphere of HD 189733 b is relatively clear (free of clouds) and that the planet likely formed far from its star, where it is cold enough to find water in the form of ice. A strong blueshift of water absorption was observed, which could be a consequence of the presence of strong winds in the atmosphere.

Artistic representation of the exoplanet HD 189733 b, credit :  NASA, ESA, and G. Bacon (STScI)

Next, we studied WASP-127 b, a less massive exoplanet, but much larger than Saturn. A recent study of data from the Hubble Space Telescope (HST) and the Spitzer Space Telescope could not differentiate between two atmospheric scenarios: a low carbon-to-oxygen (C/O) ratio with little carbon monoxide (CO), or a high ratio with a lot of CO. As this ratio helps to determine how a planet was formed, we decided to use SPIRou, which makes it possible to observe a band of CO not observable with HST and Spitzer. We were able to determine that there was very little CO and a very low C/O, which has rarely been observed, but which is supported by some more realistic training scenarios that vary over time. The SPIRou data also confirmed the presence of water and suggests that, if confirmed, there could even be hydroxyl (OH): an unexpected detection since the exoplanet is so cold.

This work has allowed to develop the expertise of the Université de Montréal in high resolution near-infrared transit spectroscopy, in particular with SPIRou, allowing to explore the atmospheric conditions of hot Jupiters and sub-Saturns. This first joint analysis made on high and low resolution transmission data allowed to obtain better constraints on the atmospheric parameters. This method is proving to be a very powerful tool for the study of atmospheres and will be even more so with the revolutionary capabilities of JWST.

More information

Anne worked on her Ph.D. at the Université de Montréal between 2016 and 2022, under the supervision of David Lafrenière. Her thesis will soon be available.

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Nicolas Cowan, Finalist for the 2021 Relève scientifique Prize – News | Institute for Research on Exoplanets

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Nicholas Cowan. Credit: McGill University.

Nicolas Cowan, Professor at McGill University and a member of both iREx and the McGill Space Institute, is one of the finalists for the Relève Scientifique du Québec 2021 Prize, an award which aims to highlight the commitment and excellence in research of a person 40 years of age or younger.

Nick has been a Professor in the Departments of Physics and Earth and Planetary Sciences at McGill University since 2015. He specialises in astrobiology and mainly studies the surface and atmosphere of exoplanets. He is particularly interested in the climate of these planets found outside of our Solar System.

The researcher mainly uses space- and ground-based telescopes to collect and analyse data which he uses to study the characteristics of various exoplanets. More specifically, the data seeks to measure the reflection of clouds, detect the presence of greenhouse gases via the infrared signature of the atmosphere, and heat transport, i.e. the winds. These data are used to create maps of the surface and the temperature of exoplanets, a method commonly referred to as exo-cartography. The study of the exoplanets’ climate also allows us to learn a lot about that of our planet, Earth.

Nick’s commitment to the research community is illustrated in particular by his participation in numerous NASA and Canadian Space Agency committees to promote the study of planetary climates and to contribute to the planning of future space missions to study exoplanets.

In addition to his work as a researcher, Nick is also involved in the Astronomy in Indigenous Communities program, which aims to attract Indigenous youth to pursue a career in STEM.

It is with pride that the iREx congratulates Nicolas Cowan for this distinction.

About the Relève scientifique du Québec Prize

The Relève scientifique du Québec prize is awarded to a person aged 40 or under who has distinguished themselves by the excellence of their research and who demonstrates the ability to establish and maintain constructive and lasting links with the research community. All disciplines are recognised for this award. Each year one recipient and two finalists are selected.

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NASA: Contact lost with spacecraft on way to test moon orbit – Phys.org

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Rebecca Rogers, systems engineer, left, takes dimension measurements of the CAPSTONE spacecraft in April 2022, at Tyvak Nano-Satellite Systems, Inc., in Irvine, Calif. NASA said Tuesday, July 5, that it has lost contact with a $32.7 million spacecraft headed to moon to test out a lopsided lunar orbit, but agency engineers are hopeful they can fix the problem. Credit: Dominic Hart/NASA via AP

NASA said Tuesday it has lost contact with a $32.7 million spacecraft headed to the moon to test out a lopsided lunar orbit, but agency engineers are hopeful they can fix the problem.

After one successful communication and a second partial one on Monday, the said it could no longer communicate with the spacecraft called Capstone. Engineers are trying to find the cause of the communications drop-off and are optimistic they can fix it, NASA spokesperson Sarah Frazier said Tuesday.

The spacecraft, which launched from New Zealand on June 28, had spent nearly a week in Earth orbit and had been successfully kick-started on its way to the moon, when contact was lost, Frazier said.

[embedded content]

The 55-pound satellite is the size of a microwave oven and will be the first spacecraft to try out this oval orbit, which is where NASA wants to stage its Gateway outpost. Gateway would serve as a staging point for astronauts before they descend to the .

The orbit balances the gravities of Earth and the moon and so requires little maneuvering and therefore fuel and allows the satellite—or a —to stay in constant contact with Earth.


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NASA satellite breaks from orbit around Earth, heads to moon


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