Tag Archives: Anne S. Meyer

Mini T-shirt demonstrates photosynthetic living materials

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Caption: A mini T-shirt demonstrates the photosynthetic living materials created in the lab of University Rochester biologist Anne S. Meyer and Delft University of Technology bionanoscientist Marie-Eve Aubin-Tam using 3D printers and a new bioink technique. Credit: University of Rochester photo

I’m not sure how I feel about a t-shirt, regardless of size, made of living biological material but these researchers seem uniformly enthusiastic. From a May 3, 2021 news item on phys.org (Note: A link has been removed),

Living materials, which are made by housing biological cells within a non-living matrix, have gained popularity in recent years as scientists recognize that often the most robust materials are those that mimic nature.

For the first time, an international team of researchers from the University of Rochester [located in New York state, US] and Delft University of Technology in the Netherlands used 3D printers and a novel bioprinting technique to print algae into living, photosynthetic materials that are tough and resilient. The material has a variety of applications in the energy, medical, and fashion sectors. The research is published in the journal Advanced Functional Materials.

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An April 30, 2021 University of Rochester new release (also on EurekAlert but published May 3, 2021) by Lindsey Valich, which originated the news item, delves further into the topic of living materials,

“Three-dimensional printing is a powerful technology for fabrication of living functional materials that have a huge potential in a wide range of environmental and human-based applications.” says Srikkanth Balasubramanian, a postdoctoral research associate at Delft and the first author of the paper. “We provide the first example of an engineered photosynthetic material that is physically robust enough to be deployed in real-life applications.”

HOW TO BUILD NEW MATERIALS: LIVING AND NONLIVING COMPONENTS

To create the photosynthetic materials, the researchers began with a non-living bacterial cellulose–an organic compound that is produced and excreted by bacteria. Bacterial cellulose has many unique mechanical properties, including its flexibility, toughness, strength, and ability to retain its shape, even when twisted, crushed, or otherwise physically distorted.

The bacterial cellulose is like the paper in a printer, while living microalgae acts as the ink. The researchers used a 3D printer to deposit living algae onto the bacterial cellulose.

The combination of living (microalgae) and nonliving (bacterial cellulose) components resulted in a unique material that has the photosynthetic quality of the algae and the robustness of the bacterial cellulose; the material is tough and resilient while also eco-friendly, biodegradable, and simple and scalable to produce. The plant-like nature of the material means it can use photosynthesis to “feed” itself over periods of many weeks, and it is also able to be regenerated–a small sample of the material can be grown on-site to make more materials.

ARTIFICIAL LEAVES, PHOTOSYNTHETIC SKINS, AND BIO-GARMENTS

The unique characteristics of the material make it an ideal candidate for a variety of applications, including new products such as artificial leaves, photosynthetic skins, or photosynthetic bio-garments.

Artificial leaves are materials that mimic actual leaves in that they use sunlight to convert water and carbon dioxide–a major driver of climate change–into oxygen and energy, much like leaves during photosynthesis. The leaves store energy in chemical form as sugars, which can then be converted into fuels. Artificial leaves therefore offer a way to produce sustainable energy in places where plants don’t grow well, including outer space colonies. The artificial leaves produced by the researchers at Delft and Rochester are additionally made from eco-friendly materials, in contrast to most artificial leaf technologies currently in production, which are produced using toxic chemical methods.

“For artificial leaves, our materials are like taking the ‘best parts’ of plants–the leaves–which can create sustainable energy, without needing to use resources to produce parts of plants–the stems and the roots–that need resources but don’t produce energy,” says Anne S. Meyer, an associate professor of biology at Rochester. “We are making a material that is only focused on the sustainable production of energy.”

Another application of the material would be photosynthetic skins, which could be used for skin grafts, Meyer says. “The oxygen generated would help to kick-start healing of the damaged area, or it might be able to carry out light-activated wound healing.”

Besides offering sustainable energy and medical treatments, the materials could also change the fashion sector. Bio-garments made from algae would address some of the negative environmental effects of the current textile industry in that they would be high-quality fabrics that would be sustainability produced and completely biodegradable. They would also work to purify the air by removing carbon dioxide through photosynthesis and would not need to be washed as often as conventional garments, reducing water usage.

“Our living materials are promising because they can survive for several days with no water or nutrients access, and the material itself can be used as a seed to grow new living materials,” says Marie-Eve Aubin-Tam, an associate professor of bionanoscience at Delft. “This opens the door to applications in remote areas, even in space, where the material can be seeded on site.”

Here’s a link to and a citation for the paper,

Bioprinting of Regenerative Photosynthetic Living Materials by Srikkanth Balasubramanian, Kui Yu, Anne S. Meyer, Elvin Karana, Marie-Eve Aubin-Tam DOI: https://doi.org/10.1002/adfm.202011162 First published: 29 April 2021

This paper is open access.

The researchers have provided this artistic impression of 3D printing of living (microalgae) and nonliving materials (bacterial cellulose),

An artist’s illustration demonstrates how 3D printed materials could be applied as durable, living clothing. (Lizah van der Aart illustration)

Bacteria and graphene oxide as a basis for producing computers

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A July 10, 2019 news item on ScienceDaily announces a more environmentally friendly way to produce graphene leading to more environmentally friendly devices such as computers,

In order to create new and more efficient computers, medical devices, and other advanced technologies, researchers are turning to nanomaterials: materials manipulated on the scale of atoms or molecules that exhibit unique properties.

Graphene — a flake of carbon as thin as a single later of atoms — is a revolutionary nanomaterial due to its ability to easily conduct electricity, as well as its extraordinary mechanical strength and flexibility. However, a major hurdle in adopting it for everyday applications is producing graphene at a large scale, while still retaining its amazing properties.

In a paper published in the journal ChemOpen, Anne S. Meyer, an associate professor of biology at the University of Rochester [New York state, US], and her colleagues at Delft University of Technology in the Netherlands, describe a way to overcome this barrier. The researchers outline their method to produce graphene materials using a novel technique: mixing oxidized graphite with bacteria. Their method is a more cost-efficient, time-saving, and environmentally friendly way of producing graphene materials versus those produced chemically, and could lead to the creation of innovative computer technologies and medical equipment.

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A July 10, 2019 University of Rochester news release (also on EurekAlert), which originated the news item, provides details as to how this new technique for extracting graphene differs from the technique currently used,

Graphene is extracted from graphite, the material found in an ordinary pencil. At exactly one atom thick, graphene is the thinnest–yet strongest–two-dimensional material known to researchers. Scientists from the University of Manchester in the United Kingdom were awarded the 2010 Nobel Prize in Physics for their discovery of graphene; however, their method of using sticky tape to make graphene yielded only small amounts of the material.

“For real applications you need large amounts,” Meyer says. “Producing these bulk amounts is challenging and typically results in graphene that is thicker and less pure. This is where our work came in.”

In order to produce larger quantities of graphene materials, Meyer and her colleagues started with a vial of graphite. They exfoliated the graphite–shedding the layers of material–to produce graphene oxide (GO), which they then mixed with the bacteria Shewanella. They let the beaker of bacteria and precursor materials sit overnight, during which time the bacteria reduced the GO to a graphene material.

“Graphene oxide is easy to produce, but it is not very conductive due to all of the oxygen groups in it,” Meyer says. “The bacteria remove most of the oxygen groups, which turns it into a conductive material.”

While the bacterially-produced graphene material created in Meyer’s lab is conductive, it is also thinner and more stable than graphene produced chemically. It can additionally be stored for longer periods of time, making it well suited for a variety of applications, including field-effect transistor (FET) biosensors and conducting ink. FET biosensors are devices that detect biological molecules and could be used to perform, for example, real-time glucose monitoring for diabetics.

“When biological molecules bind to the device, they change the conductance of the surface, sending a signal that the molecule is present,” Meyer says. “To make a good FET biosensor you want a material that is highly conductive but can also be modified to bind to specific molecules.” Graphene oxide that has been reduced is an ideal material because it is lightweight and very conductive, but it typically retains a small number of oxygen groups that can be used to bind to the molecules of interest.

The bacterially produced graphene material could also be the basis for conductive inks, which could, in turn, be used to make faster and more efficient computer keyboards, circuit boards, or small wires such as those used to defrost car windshields. Using conductive inks is an “easier, more economical way to produce electrical circuits, compared to traditional techniques,” Meyer says. Conductive inks could also be used to produce electrical circuits on top of nontraditional materials like fabric or paper.

“Our bacterially produced graphene material will lead to far better suitability for product development,” Meyer says. “We were even able to develop a technique of ‘bacterial lithography’ to create graphene materials that were only conductive on one side, which can lead to the development of new, advanced nanocomposite materials.”

Here’s a link to and a citation for the paper,

Creation of Conductive Graphene Materials by Bacterial Reduction Using Shewanella Oneidensis by Benjamin A. E. Lehner, Vera A. E. C. Janssen, Dr. Ewa M. Spiesz, Dominik Benz, Dr. Stan J. J. Brouns, Dr. Anne S. Meyer, Prof. Dr. Herre S. J. van der Zant. ChemistryOpen Volume 8, Issue 7 July 2019 Pages 888-895 DOI: https://doi.org/10.1002/open.201900186
First published: 04 July 2019

As you would expect given the journal’s title, this paper is open access.