A lobster’s stretch and strength in a hydrogel

An MIT team has fabricated a hydrogel-based material that mimics the structure of the lobster’s underbelly, the toughest known hydrogel found in nature. Credits: Courtesy of the researchers

I love this lobster. In most photos, they’re food. This shows off the lobster as a living entity while showcasing its underbelly, which is what this story is all about. From an April 23, 2021 news item on phys.org (Note: A link has been removed),

A lobster’s underbelly is lined with a thin, translucent membrane that is both stretchy and surprisingly tough. This marine under-armor, as MIT [Massachusetts Institute of Technology] engineers reported in 2019, is made from the toughest known hydrogel in nature, which also happens to be highly flexible. This combination of strength and stretch helps shield a lobster as it scrabbles across the seafloor, while also allowing it to flex back and forth to swim.

Now a separate MIT team has fabricated a hydrogel-based material that mimics the structure of the lobster’s underbelly. The researchers ran the material through a battery of stretch and impact tests, and showed that, similar to the lobster underbelly, the synthetic material is remarkably “fatigue-resistant,” able to withstand repeated stretches and strains without tearing.

If the fabrication process could be significantly scaled up, materials made from nanofibrous hydrogels could be used to make stretchy and strong replacement tissues such as artificial tendons and ligaments.

The team’s results are published in the journal Matter. The paper’s MIT co-authors include postdocs Jiahua Ni and Shaoting Lin; graduate students Xinyue Liu and Yuchen Sun; professor of aeronautics and astronautics Raul Radovitzky; professor of chemistry Keith Nelson; mechanical engineering professor Xuanhe Zhao; and former research scientist David Veysset Ph.D. ’16, now at Stanford University; along with Zhao Qin, assistant professor at Syracuse University, and Alex Hsieh of the Army Research Laboratory.

An April 23, 2021 MIT news release (also on EurekAlert) by Jennifer Chu, which originated the news item, offers an overview of the groundwork for this latest research along with technical detail about the latest work,

Nature’s twist

In 2019, Lin and other members of Zhao’s group developed a new kind of fatigue-resistant material made from hydrogel — a gelatin-like class of materials made primarily of water and cross-linked polymers. They fabricated the material from ultrathin fibers of hydrogel, which aligned like many strands of gathered straw when the material was repeatedly stretched. This workout also happened to increase the hydrogel’s fatigue resistance.

“At that moment, we had a feeling nanofibers in hydrogels were important, and hoped to manipulate the fibril structures so that we could optimize fatigue resistance,” says Lin.

In their new study, the researchers combined a number of techniques to create stronger hydrogel nanofibers. The process starts with electrospinning, a fiber production technique that uses electric charges to draw ultrathin threads out of polymer solutions. The team used high-voltage charges to spin nanofibers from a polymer solution, to form a flat film of nanofibers, each measuring about 800 nanometers — a fraction of the diameter of a human hair.

They placed the film in a high-humidity chamber to weld the individual fibers into a sturdy, interconnected network, and then set the film in an incubator to crystallize the individual nanofibers at high temperatures, further strengthening the material.

They tested the film’s fatigue-resistance by placing it in a machine that stretched it repeatedly over tens of thousands of cycles. They also made notches in some films and observed how the cracks propagated as the films were stretched repeatedly. From these tests, they calculated that the nanofibrous films were 50 times more fatigue-resistant than the conventional nanofibrous hydrogels.

Around this time, they read with interest a study by Ming Guo, associate professor of mechanical engineering at MIT, who characterized the mechanical properties of a lobster’s underbelly. This protective membrane is made from thin sheets of chitin, a natural, fibrous material that is similar in makeup to the group’s hydrogel nanofibers.

Guo found that a cross-section of the lobster membrane revealed sheets of chitin stacked at 36-degree angles, similar to twisted plywood, or a spiral staircase. This rotating, layered configuration, known as a bouligand structure, enhanced the membrane’s properties of stretch and strength.

“We learned that this bouligand structure in the lobster underbelly has high mechanical performance, which motivated us to see if we could reproduce such structures in synthetic materials,” Lin says.

Angled architecture

Ni, Lin, and members of Zhao’s group teamed up with Nelson’s lab and Radovitzky’s group in MIT’s Institute for Soldier Nanotechnologies, and Qin’s lab at Syracuse University, to see if they could reproduce the lobster’s bouligand membrane structure using their synthetic, fatigue-resistant films.

“We prepared aligned nanofibers by electrospinning to mimic the chinic fibers existed in the lobster underbelly,” Ni says.

After electrospinning nanofibrous films, the researchers stacked each of five films in successive, 36-degree angles to form a single bouligand structure, which they then welded and crystallized to fortify the material. The final product measured 9 square centimeters and about 30 to 40 microns thick — about the size of a small piece of Scotch tape.

Stretch tests showed that the lobster-inspired material performed similarly to its natural counterpart, able to stretch repeatedly while resisting tears and cracks — a fatigue-resistance Lin attributes to the structure’s angled architecture.

“Intuitively, once a crack in the material propagates through one layer, it’s impeded by adjacent layers, where fibers are aligned at different angles,” Lin explains.

The team also subjected the material to microballistic impact tests with an experiment designed by Nelson’s group. They imaged the material as they shot it with microparticles at high velocity, and measured the particles’ speed before and after tearing through the material. The difference in velocity gave them a direct measurement of the material’s impact resistance, or the amount of energy it can absorb, which turned out to be a surprisingly tough 40 kilojoules per kilogram. This number is measured in the hydrated state.

“That means that a 5-millimeter steel ball launched at 200 meters per second would be arrested by 13 millimeters of the material,” Veysset says. “It is not as resistant as Kevlar, which would require 1 millimeter, but the material beats Kevlar in many other categories.”

It’s no surprise that the new material isn’t as tough as commercial antiballistic materials. It is, however, significantly sturdier than most other nanofibrous hydrogels such as gelatin and synthetic polymers like PVA. The material is also much stretchier than Kevlar. This combination of stretch and strength suggests that, if their fabrication can be sped up, and more films stacked in bouligand structures, nanofibrous hydrogels may serve as flexible and tough artificial tissues.

“For a hydrogel material to be a load-bearing artificial tissue, both strength and deformability are required,” Lin says. “Our material design could achieve these two properties.”

If you have the time and the interest, do check out the April 23, 2021 MIT news release, which features a couple of informative GIFs.

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

Strong fatigue-resistant nanofibrous hydrogels inspired by lobster underbelly by Jiahua Ni, Shaoting Lin, Zhao Qin, David Veysset, Xinyue Liu, Yuchen Sun, Alex J. Hsieh, Raul Radovitzky, Keith A. Nelson, Xuanhe Zhao. Matter, 2021; DOI: 10.1016/j.matt.2021.03.023 Published April 23, 2021

This paper is behind a paywall.

Nanomaterials are now nanoforms?

There’s a proposal/recommendation/call to start calling nanomaterials ‘nanoforms’ according to an April 20, 2021 article (you can also find it here on JDSupra) by Lynn Bergeson and Carla N. Hutton in April 27, 2021 (Volume XI, Number 117) issue of the National Law Review,

The Nanotechnology Industries Association (NIA) has published a March 2021 position paper, A changing regulatory landscape and language for the nanoscale, that examines the transition from “nanomaterial” to “nanoforms” to reflect better the differences in nanomaterial properties both in relation to bulk counterparts and to nanoforms of the same substance.  In the paper, NIA describes a transition phase where the language of nanoforms is used more widely and examples of nanoform sets can be increasingly demonstrated in the public domain, while there is still a “significant” learning curve for both industry and the European Chemicals Agency (ECHA).  NIA recommends that all stakeholders reassess the language they use where relevant, “particularly when discussing hazard, and where non-specific terminology may be misleading and result in confusion and mistrust in the safety of substances at the nanoscale.” …

I haven’t noticed the use of nanoforms yet but, going forward, I will be alert to the change in terminology.

Entanglement-based quantum network courtesy of Dutch researchers

Belated congratulations to the researchers at the Delft University of Technology! Very exciting news as an April 15, 2021 news item on ScienceDaily makes clear,

A team of researchers from QuTech in the Netherlands reports realization of the first multi-node quantum network, connecting three quantum processors. In addition, they achieved a proof-of-principle demonstration of key quantum network protocols. Their findings mark an important milestone towards the future quantum internet and have now been published in Science.

An April 15, 2021 Delft University of Technology (TU Delft) press release (also on EurekAlert), which originated the news item, describes the breakthrough in more detail, Note: QuTech is the research center for Quantum Computing and Quantum Internet, a collaboration between TU Delft and TNO is Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek (English: Netherlands Organisation for Applied Scientific Research), an independent research organization),

The quantum internet

The power of the Internet is that it allows any two computers on Earth to be connected with each other, enabling applications undreamt of at the time of its creation decades ago. Today, researchers in many labs around the world are working towards first versions of a quantum internet – a network that can connect any two quantum devices, such as quantum computers or sensors, over large distances. Whereas today’s Internet distributes information in bits (that can be either 0 or 1), a future quantum internet will make use of quantum bits that can be 0 and 1 at the same time. ‘A quantum internet will open up a range of novel applications, from unhackable communication and cloud computing with complete user privacy to high-precision time-keeping,’ says Matteo Pompili, PhD student and a member of the research team. ‘And like with the Internet 40 years ago, there are probably many applications we cannot foresee right now.’

Towards ubiquitous connectivity

The first steps towards a quantum internet were taken in the past decade by linking two quantum devices that shared a direct physical link. However, being able to pass on quantum information through intermediate nodes (analogous to routers in the classical internet) is essential for creating a scalable quantum network. In addition, many promising quantum internet applications rely on entangled quantum bits, to be distributed between multiple nodes. Entanglement is a phenomenon observed at the quantum scale, fundamentally connecting particles at small and even at large distances. It provides quantum computers their enormous computational power and it is the fundamental resource for sharing quantum information over the future quantum internet. By realizing their quantum network in the lab, a team of researchers at QuTech – a collaboration between Delft University of Technology and TNO – is the first to have connected two quantum processors through an intermediate node and to have established shared entanglement between multiple stand-alone quantum processors.

Operating the quantum network

The rudimentary quantum network consists of three quantum nodes, at some distance within the same building. To make these nodes operate as a true network, the researchers had to invent a novel architecture that enables scaling beyond a single link. The middle node (called Bob) has a physical connection to both outer nodes (called Alice and Charlie), allowing entanglement links with each of these nodes to be established. Bob is equipped with an additional quantum bit that can be used as memory, allowing a previously generated quantum link to be stored while a new link is being established. After establishing the quantum links Alice-Bob and Bob-Charlie, a set of quantum operations at Bob converts these links into a quantum link Alice-Charlie. Alternatively, by performing a different set of quantum operations at Bob, entanglement between all three nodes is established.

Ready for subsequent use

An important feature of the network is that it announces the successful completion of these (intrinsically probabilistic) protocols with a “flag” signal. Such heralding is crucial for scalability, as in a future quantum internet many of such protocols will need to be concatenated. ‘Once established, we were able to preserve the resulting entangled states, protecting them from noise,’ says Sophie Hermans, another member of the team. ‘It means that, in principle, we can use these states for quantum key distribution, a quantum computation or any other subsequent quantum protocol.’

Quantum Internet Demonstrator

This first entanglement-based quantum network provides the researchers with a unique testbed for developing and testing quantum internet hardware, software and protocols. ‘The future quantum internet will consist of countless quantum devices and intermediate nodes,’ says Ronald Hanson, who led the research team. ‘Colleagues at QuTech are already looking into future compatibility with existing data infrastructures.’ In due time, the current proof-of-principle approach will be tested outside the lab on existing telecom fibre – on QuTech’s Quantum Internet Demonstrator, of which the first metropolitan link is scheduled to be completed in 2022.

Higher-level layers

In the lab, the researchers will focus on adding more quantum bits to their three-node network and on adding higher level software and hardware layers. Pompili: ‘Once all the high-level control and interface layers for running the network have been developed, anybody will be able to write and run a network application without needing to understand how lasers and cryostats work. That is the end goal.’

This news has likely lit some competitive fires in the research community. I think this is the first time I’ve featured news about the quantum internet since 2016 when, as it turns out, it was research from the University of Calgary that piqued my interest. See Teleporting photons in Calgary (Canada) is a step towards a quantum internet (a September 21, 2016 posting).

Here’s a link to and a citation for this latest work

Realization of a multinode quantum network of remote solid-state qubits by M. Pompili, S. L. N. Hermans, S. Baier, H. K. C. Beukers, P. C. Humphreys, R. N. Schouten, R. F. L. Vermeulen, M. J. Tiggelman, L. dos Santos Martins, B. Dirkse, S. Wehner, R. Hanson. Science 16 Apr 2021: Vol. 372, Issue 6539, pp. 259-264 DOI: 10.1126/science.abg1919

This paper is behind a paywall.

There is a video which introduces the concept of a quantum internet,

I am a book. I am a portal to …

Interactive data visualization for children who want to learn about the universe in the form of a book was published by Penguin Books as “I am a book. I am a portal to the universe.” was first published in 2020. As of April 2021, it has crossed the Atlantic Ocean occasioning an April 16, 2021 article by Mark Wilson for Fast Company (Note: Links have been removed),

… A collaboration between data-centric designer Stefanie Posavec and data journalist Miriam Quick, …

“The pared-back aesthetic is due to the book’s core concept. The whole book, even the endnotes and acknowledgements, is written in the first person, in the book’s own voice. [emphasis mine] It developed its own rather theatrical character as we worked on it,” says Posavec. “The book speaks directly to the reader using whatever materials it has at its disposal to communicate the wonders of our universe. In the purest sense, that means the book’s paper and binding, its typeface and its CMYK [cyan, magenta, yellow, black] ink, or, as the book would call them, its ‘superpowers.’” [emphases mine]

It’s hard to explain without actually experiencing it. Which is exactly why it’s so much fun. For instance, at one moment, the book asks you to put it on your head [emphasis mine] and take it off. That difference in weight you feel? That’s how much lighter you are on the top of a mountain than at sea level, the book explains, because of the difference in gravity at different altitudes. …

I recommend reading Wilson’s April 16, 2021 article in its entirety if you have the time as it is peppered with images, GIFs, and illustrative stories.

The “I am a book. I am a portal to the universe.” website offers more details,

“Typography and design combine thrillingly to form something that is

eye-opening in

every sense”

— Financial Times

Hello. I am a book.
But I’m also a portal to the universe.

I have 112 pages, measuring 20cm high and wide. I weigh 450g. And I have the power to show you the wonders of the world.

I’m different to any other book around today. I am not a book of infographics. I’m an informative, interactive experience, in which the data can be touched, felt and understood, with every measurement represented on a 1:1 scale. How long is an anteater’s tongue? How tiny is the DNA in your cells? How fast is gold mined? How loud is the sun? And how many stars have been born and exploded in the time you’ve taken to read this sentence?

… 

There is a September 2020 Conversations with Data podcast: Episode 13 (hosted by Tara Kelly on Spotify) featuring Stefanie Posavec (data-centric designer) and Miriam Quick (data journalist) discussing their book.

You can find Miriam Quick’s website here and Stefanie Posavec’s website here.

Israel’s Fetter Museum of Nanoscience & Art opens on Thursday, July 8, 2021

According to a July 5, 2021 news article by Maya Margit in the Jerusalem Post (originally published by The Media Line) The Fetter Museum of Nanoscience & Art will be opening at Bar-Ilan University’s Institute of Nanotechnology and Advanced Materials (BINA)* this Thursday, July 8, 2021 (Note: Links have been removed),

A new museum set to open in Israel this week combines the cutting-edge field of nanotechnology with the world of contemporary art to create a uniquely mind-bending experience.

The Fetter Nanoscience and Art Museum located at Bar-Ilan University’s Institute of Nanotechnology and Advanced Materials (BINA), pushes the limits of creative expression with a series of artworks that are exhibited throughout the institute’s seven floors.

This museum seems to be conceptual as it is ‘found’ in spaces within BINA rather than having its own designated space within BINA or its own ‘brick and mortar’ structure.

For the curious, there is a Fetter Museum of Nanoscience & Art website where some sections still seem to be under construction.

Back to Margit’s July 5, 2021 news article,

Slated to open to the public on Thursday [July 8, 2021], the museum is the brainchild of acclaimed physics professor Yuval Garini, former director of BINA.

As he was wandering down the spacious halls of the institute one day, Garini realized that much could be done to make better use of the expansive central rooms and meeting areas at BINA.

“Nanotechnology is an interdisciplinary field so you really have to have the scientists from different disciplines working together to get something really novel,” Garini told The Media Line, adding that one of the primary purposes of the museum is to attract youngsters to join the burgeoning field of nanotechnology.

The museum has taken years to launch as evidenced by a November 2018 BINA newsletter issue 9 announcement,

Joseph Fetter Museum of Nanotechnology

The Nano-Art Museum will showcase breakthrough research conducted at the Institute, fusing art and science to create an interactive thought-provoking experience.

Art that speaks science

“It started several years ago as a dream to establish a nanotechnology museum through a collaborative process of scientists and artists,” said Prof. Yuval Garini, the visionary and driving force behind the project. “We wanted to dazzle visitors with magnificent experiences, exposing them to scientific principles and to the vast research possibilities in the natural sciences. I am deeply grateful to the Fetter family, whom, without their gracious help our vision would not have been realized”, he said.

The Nano-Art museum is scheduled to open in the summer of 2019, offering visitors a wondrous celebration of the senses. …

Bravo to professor Garini and the others whose continued determination has resulted in the museum.

Back again to Margit’s July 5, 2021 news article,

The launch show, Titled “New Languages,” features collaborations between artists and scientists from a wide variety of nanotechnology-related disciplines, including biology, computer science, engineering and chemistry.

New works will be added as time goes by and as these dialogues continue, she said. Unlike traditional white cube museums, the art at the Fetter Museum is exhibited in the institute’s main halls and in between its research labs, making for a one-of-a-kind museum experience in Israel.

Artist Vardi Bobrow, for instance, created an imposing large-scale sculptural installation called “Stretching the Limits” in BINA’s main hall that consists of a staggering 15,000 rubber bands. The rubber bands are intended to illustrate how damaged neurons recover by stretching and growing, an area of research that was explored by Prof. Orit Shefi. 

It’s not clear if they will be hosting an event of some kind; I was not able to find any press releases.

*ETA July 6.21 0840 PDT: Bar-Ilan University is in the city of Ramat Gan in the Tel Aviv District.

New water treatment with 3D-printed graphene aerogels

Caption: Graphene aerogel on a single tissue. Credit: University at Buffalo

That image of the graphene aerogel on a tissue shows off its weightlessness very well.

Here’s more about the graphene aerogel water treatment from an April 14, 2021 news item on Nanowerk,

Graphene excels at removing contaminants from water, but it’s not yet a commercially viable use of the wonder material.

That could be changing.

In a recent study, University at Buffalo [UB] engineers report a new process of 3D printing graphene aerogels that they say overcomes two key hurdles — scalability and creating a version of the material that’s stable enough for repeated use — for water treatment.

“The goal is to safely remove contaminants from water without releasing any problematic chemical residue,” says study co-author Nirupam Aich, PhD, assistant professor of environmental engineering at the UB School of Engineering and Applied Sciences. “The aerogels we’ve created hold their structure when put in water treatment systems, and they can be applied in diverse water treatment applications.”

An April 14, 2021 UB news release (also on EurekAlert) by Melvin Bankhead III, which originated the news item, explains the breakthrough in more detail,

An aerogel is a light, highly porous solid formed by replacement of liquid in a gel with a gas so that the resulting solid is the same size as the original. They are similar in structural configuration to Styrofoam: very porous and lightweight, yet strong and resilient.

Graphene is a nanomaterial formed by elemental carbon and is composed of a single flat sheet of carbon atoms arranged in a repeating hexagonal lattice.

To create the right consistency of the graphene-based ink, the researchers looked to nature. They added to it two bio-inspired polymers — polydopamine (a synthetic material, often referred to as PDA, that is similar to the adhesive secretions of mussels), and bovine serum albumin (a protein derived from cows).

In tests, the reconfigured aerogel removed certain heavy metals, such as lead and chromium, that plague drinking water systems nationwide. It also removed organic dyes, such as cationic methylene blue and anionic Evans blue, as well as organic solvents like hexane, heptane and toluene.

To demonstrate the aerogel’s reuse potential, the researchers ran organic solvents through it 10 times. Each time, it removed 100% of the solvents. The researchers also reported the aerogel’s ability to capture methylene blue decreased by 2-20% after the third cycle.

The aerogels can also be scaled up in size, Aich says, because unlike nanosheets, aerogels can be printed in larger sizes. This eliminates a previous problem inherent in large-scale production, and makes the process available for use in large facilities, such as in wastewater treatment plants, he says. He adds the aerogels can be removed from water and reused in other locations, and that they don’t leave any kind of residue in the water.

Aich is part of a collaboration between UB and the University of Pittsburgh, led by UB chemistry professor Diana Aga, PhD, to find methods and tools to degrade per- and polyfluoroalkyl substances (PFAS), toxic materials so difficult to break down that they are known as “forever chemicals.” Aich notes the similarities to his work with 3D aerogels, and he hopes results from the two projects can be brought together to create more effective methods of removing waterborne contaminants.

“We can use these aerogels not only to contain graphene particles but also nanometal particles which can act as catalysts,” Aich says. “The future goal is to have nanometal particles embedded in the walls and the surface of these aerogels and they would be able to degrade or destroy not only biological contaminants, but also chemical contaminants.”

Aich, Chi, and Masud [Arvid Masud, PhD] hold a pending patent for the graphene aerogel described in the study, and they are looking for industrial partners to commercialize this process.

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

Emerging investigator series: 3D printed graphene-biopolymer aerogels for water contaminant removal: a proof of concept by Arvid Masud, Chi Zhoub and Nirupam Aich. Environ. Sci.: Nano, 2021,8, 399-414 DOI: https://doi.org/10.1039/D0EN00953A First published online: 09 Dec 2020

This paper is behind a paywall.

Concrete collapse and research into durability

I have two items about concrete buildings, one concerns the June 24, 2021 collapse of a 12-storey condominium building in Surfside, close to Miami Beach in Florida. There are at least 20 people dead and, I believe, over 120 are still unaccounted for (July 2, 2021 Associated Press news item on Canadian Broadcasting Corporation news online website).

Miami collapse

Nate Berg’s June 25, 2021 article for Fast Company provides an instructive overview of the building collapse (Note: A link has been removed),

Why the building collapsed is not yet known [emphasis mine]. David Darwin is a professor of civil engineering at the University of Kansas and an expert in reinforced concrete structures, and he says the eventual investigation of the Surfside collapse will explore all the potential causes, ranging from movement in the foundation before the collapse, corrosion in the debris, and excessive cracking in the part of the building that remains standing. “There are all sorts of potential causes of failure,” Darwin says. “At this point, speculation is not helpful for anybody.”

Sometimes I can access the entire article, and at other times, only a few paragraphs; I hope you get access to all of it as it provides a lot of information.

The Surfside news puts this research from Northwestern University (Chicago, Illinois) into much sharper relief than might otherwise be the case. (Further on I have some information about the difference between cement and concrete and how cement leads to concrete.)

Smart cement for more durable roads and cities

Coincidentally, just days before the Miami Beach building collapse, a June 21, 2021 Northwestern University news release (also on EurekAlert), announced research into improving water and fracture resistance in cement,

Forces of nature have been outsmarting the materials we use to build our infrastructure since we started producing them. Ice and snow turn major roads into rubble every year; foundations of houses crack and crumble, in spite of sturdy construction. In addition to the tons of waste produced by broken bits of concrete, each lane-mile of road costs the U.S. approximately $24,000 per year to keep it in good repair.

Engineers tackling this issue with smart materials typically enhance the function of materials by increasing the amount of carbon, but doing so makes materials lose some mechanical performance. By introducing nanoparticles into ordinary cement, Northwestern University researchers have formed a smarter, more durable and highly functional cement.

The research was published today (June 21 [2021]) in the journal Philosophical Transactions of the Royal Society A.

With cement being the most widely consumed material globally and the cement industry accounting for 8% of human-caused greenhouse gas emissions, civil and environmental engineering professor Ange-Therese Akono turned to nanoreinforced cement to look for a solution. Akono, the lead author on the study and an assistant professor in the McCormick School of Engineering, said nanomaterials reduce the carbon footprint of cement composites, but until now, little was known about its impact on fracture behavior.

“The role of nanoparticles in this application has not been understood before now, so this is a major breakthrough,” Akono said. “As a fracture mechanics expert by training, I wanted to understand how to change cement production to enhance the fracture response.”

Traditional fracture testing, in which a series of light beams is cast onto a large block of material, involves lots of time and materials and seldom leads to the discovery of new materials.

By using an innovative method called scratch testing, Akono’s lab efficiently formed predictions on the material’s properties in a fraction of the time. The method tests fracture response by applying a conical probe with increasing vertical force against the surface of microscopic bits of cement. Akono, who developed the novel method during her Ph.D. work, said it requires less material and accelerates the discovery of new ones.

“I was able to look at many different materials at the same time,” Akono said. “My method is applied directly at the micrometer and nanometer scales, which saves a considerable amount of time. And then based on this, we can understand how materials behave, how they crack and ultimately predict their resistance to fracture.”

Predictions formed through scratch tests also allow engineers to make changes to materials that enhance their performance at the larger scale. In the paper, graphene nanoplatelets, a material rapidly gaining popularity in forming smart materials, were used to improve the resistance to fracture of ordinary cement. Incorporating a small amount of the nanomaterial also was shown to improve water transport properties including pore structure and water penetration resistance, with reported relative decreases of 76% and 78%, respectively.

Implications of the study span many fields, including building construction, road maintenance, sensor and generator optimization and structural health monitoring.

By 2050, the United Nations predicts two-thirds of the world population will be concentrated in cities. Given the trend toward urbanization, cement production is expected to skyrocket.

Introducing green concrete that employs lighter, higher-performing cement will reduce its overall carbon footprint by extending maintenance schedules and reducing waste.

Alternately, smart materials allow cities to meet the needs of growing populations in terms of connectivity, energy and multifunctionality. Carbon-based nanomaterials including graphene nanoplatelets are already being considered in the design of smart cement-based sensors for structural health monitoring.

Akono said she’s excited for both follow-ups to the paper in her own lab and the ways her research will influence others. She’s already working on proposals that look into using construction waste to form new concrete and is considering “taking the paper further” by increasing the fraction of nanomaterial that cement contains.

“I want to look at other properties like understanding the long-term performance,” Akono said. “For instance, if you have a building made of carbon-based nanomaterials, how can you predict the resistance in 10, 20 even 40 years?”

The study, “Fracture toughness of one- and two-dimensional nanoreinforced cement via scratch testing,” was supported by the National Science Foundation Division of Civil, Mechanical and Manufacturing Innovation (award number 18929101).

Akono will give a talk on the paper at The Royal Society’s October [2021] meeting, “A Cracking Approach to Inventing Tough New Materials: Fracture Stranger Than Friction,” which will highlight major advances in fracture mechanics from the past century.

I don’t often include these kinds of photos (one or more of the researchers posing (sometimes holding something) for the camera but I love the professor’s first name, Ange-Therese (which means angel in French, I don’t know if she ever uses the French spelling for Thérèse),

Caption: Professor Ange-Therese Akono holds a sample of her smart cement. Credit: Northwestern University

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

Fracture toughness of one- and two-dimensional nanoreinforced cement via scratch testing by Ange-Therese Akono. Philosophical Transactions of the Royal Society A: Mathematical, Physical & Engineering Sciences 2021 379 (2203): 20200288 DOI: 10.1098/rsta.2020.0288 Published June 21, 2021

This paper appears to be open access.

Cement vs. concrete

Andrew Logan’s April 3, 2020 article for MIT (Massachusetts Institute of Technology) News is a very readable explanation of how cement and concrete differ and how they are related,

There’s a lot the average person doesn’t know about concrete. For example, it’s porous; it’s the world’s most-used material after water; and, perhaps most fundamentally, it’s not cement.

Though many use “cement” and “concrete” interchangeably, they actually refer to two different — but related — materials: Concrete is a composite made from several materials, one of which is cement. [emphasis mine]

Cement production begins with limestone, a sedimentary rock. Once quarried, it is mixed with a silica source, such as industrial byproducts slag or fly ash, and gets fired in a kiln at 2,700 degrees Fahrenheit. What comes out of the kiln is called clinker. Cement plants grind clinker down to an extremely fine powder and mix in a few additives. The final result is cement.

“Cement is then brought to sites where it is mixed with water, where it becomes cement paste,” explains Professor Franz-Josef Ulm, faculty director of the MIT Concrete Sustainability Hub (CSHub). “If you add sand to that paste it becomes mortar. And if you add to the mortar large aggregates — stones of a diameter of up to an inch — it becomes concrete.”

Final thoughts

I offer my sympathies to the folks affected by the building collapse and my hopes that research will lead the way to more durable cement and, ultimately, concrete buildings.

2021 version of graphene-enhanced sports shoes/sneakers/running shoes/runners/trainers

My June 21, 2018 posting was the last time these graphene-enhanced sports shoes/sneakers/running shoes/runners/trainers were mentioned here (it was also the first time). The latest version features newly graphene-enhanced shoe soles that last twice as long as the industry standard according to a March 30, 2021 article by Robert Lea for Azonano (Note: A link has been removed),

Thanks to researchers at the University of Manchester and UK-based sportswear manufacturer Inov-8, graphene can now be found at the tips of your toes as well as your fingers.

In 2017 Inov-8 brought to the market the first running shoe that utilizes graphene in its grips, and 4 years later the manufacturer is still innovating, offering a wide range of products that rely on the wonder material. 

Now, as well as finding its way into the grips of the company’s running shoes, graphene is also found in the soles of the company’s latest long-distance running shoe too¹. 

Using graphene as part of the cushioning insole in trail running shoes has led to a shoe that lasts twice as long as leading competitors’ footwear, the company says.

When Inov-8 began their quest to use graphene to improve running shoes, the initial goal was to employ the material to create improved rubber grips that would not wear down as quickly as other running shoes and retain grip for longer during this slower wearing process.

The company teamed with the University of Manchester to make this goal a reality, …

The graphene-enhanced grip proved such a hit with consumers that in the four years since its induction, shoes featuring the outer-sole now account for 50% of overall sales.

Building upon the success of Inov-8’s graphene gripped running shoe, the company has expanded its use of the material to a midsole foam. The graphene replaces EVA foam plates of carbon which are traditionally used in this form of long-distance running shoe.

A March 24, 2021 University of Manchester press release describes the latest use of graphene in Inov-8’s shoes,

Sports footwear firm inov-8 has unveiled the world’s first running shoe to use a graphene-enhanced foam in the sole, bucking the widespread trend for carbon-plate technology and doubling the industry standard for longevity.

Developed in collaboration with graphene experts at The University of Manchester, the cushioned foam, called G-FLY™, features as part of inov-8’s new trail shoe, the TRAILFLY ULTRA G 300 MAX™, designed for ultramarathon and long-distance runners.

Tests have shown the foam delivers 25% greater energy return than standard EVA foams and is far more resistant to compressive wear. It therefore maintains optimum levels of underfoot bounce and comfort for much longer.

This helps runners maintain a faster speed over greater distances, aid their feet in feeling fresher for longer, and prolong the life of their footwear.

Michael Price, COO of Lake District-based inov-8, said: …

“We’ve worked incredibly hard for the past two years with the university and leading footwear industry veteran Doug Sheridan in developing this innovation. A team of 40 athletes from across the world tested prototype shoes and more than 50 mixes of graphene-enhanced foam. Trail test reports show G-FLY foam still performing well after 1,200km – double the industry standard.”

Dr Aravind Vijayaraghavan, Reader in Nanomaterials at the University, home to both the National Graphene Institute and Graphene Engineering Innovation Centre, said: “As well as on the trail, we also tested extensively in the laboratory, including subjecting the foam to aggressive ageing tests that mimic extensive use. Despite being significantly aged, the G-FLY foam still delivered more energy return than some unaged foams.

The company inov-8 can be found here.

Nanosensors use AI to explore the biomolecular world

EPFL scientists have developed AI-powered nanosensors that let researchers track various kinds of biological molecules without disturbing them. Courtesy: École polytechnique fédérale de Lausanne (EPFL)

If you look at the big orange dot (representing the nanosensors?), you’ll see those purplish/fuschia objects resemble musical notes (biological molecules?). I think that brainlike object to the left and in light blue is the artificial intelligence (AI) component. (If anyone wants to correct my guesses or identify the bits I can’t, please feel free to add to the Comments for this blog.)

Getting back to my topic, keep the ‘musical notes’ in mind as you read about some of the latest research from l’École polytechnique fédérale de Lausanne (EPFL) in an April 7, 2021 news item on Nanowerk,

The tiny world of biomolecules is rich in fascinating interactions between a plethora of different agents such as intricate nanomachines (proteins), shape-shifting vessels (lipid complexes), chains of vital information (DNA) and energy fuel (carbohydrates). Yet the ways in which biomolecules meet and interact to define the symphony of life is exceedingly complex.

Scientists at the Bionanophotonic Systems Laboratory in EPFL’s School of Engineering have now developed a new biosensor that can be used to observe all major biomolecule classes of the nanoworld without disturbing them. Their innovative technique uses nanotechnology, metasurfaces, infrared light and artificial intelligence.

To each molecule its own melody

In this nano-sized symphony, perfect orchestration makes physiological wonders such as vision and taste possible, while slight dissonances can amplify into horrendous cacophonies leading to pathologies such as cancer and neurodegeneration.

An April 7, 2021 EPFL press release, which originated the news item, provides more detail,

“Tuning into this tiny world and being able to differentiate between proteins, lipids, nucleic acids and carbohydrates without disturbing their interactions is of fundamental importance for understanding life processes and disease mechanisms,” says Hatice Altug, the head of the Bionanophotonic Systems Laboratory. 

Light, and more specifically infrared light, is at the core of the biosensor developed by Altug’s team. Humans cannot see infrared light, which is beyond the visible light spectrum that ranges from blue to red. However, we can feel it in the form of heat in our bodies, as our molecules vibrate under the infrared light excitation.

Molecules consist of atoms bonded to each other and – depending on the mass of the atoms and the arrangement and stiffness of their bonds – vibrate at specific frequencies. This is similar to the strings on a musical instrument that vibrate at specific frequencies depending on their length. These resonant frequencies are molecule-specific, and they mostly occur in the infrared frequency range of the electromagnetic spectrum. 

“If you imagine audio frequencies instead of infrared frequencies, it’s as if each molecule has its own characteristic melody,” says Aurélian John-Herpin, a doctoral assistant at Altug’s lab and the first author of the publication. “However, tuning into these melodies is very challenging because without amplification, they are mere whispers in a sea of sounds. To make matters worse, their melodies can present very similar motifs making it hard to tell them apart.” 

Metasurfaces and artificial intelligence

The scientists solved these two issues using metasurfaces and AI. Metasurfaces are man-made materials with outstanding light manipulation capabilities at the nano scale, thereby enabling functions beyond what is otherwise seen in nature. Here, their precisely engineered meta-atoms made out of gold nanorods act like amplifiers of light-matter interactions by tapping into the plasmonic excitations resulting from the collective oscillations of free electrons in metals. “In our analogy, these enhanced interactions make the whispered molecule melodies more audible,” says John-Herpin.

AI is a powerful tool that can be fed with more data than humans can handle in the same amount of time and that can quickly develop the ability to recognize complex patterns from the data. John-Herpin explains, “AI can be imagined as a complete beginner musician who listens to the different amplified melodies and develops a perfect ear after just a few minutes and can tell the melodies apart, even when they are played together – like in an orchestra featuring many instruments simultaneously.” 

The first biosensor of its kind

When the scientists’ infrared metasurfaces are augmented with AI, the new sensor can be used to analyze biological assays featuring multiple analytes simultaneously from the major biomolecule classes and resolving their dynamic interactions. 

“We looked in particular at lipid vesicle-based nanoparticles and monitored their breakage through the insertion of a toxin peptide and the subsequent release of vesicle cargos of nucleotides and carbohydrates, as well as the formation of supported lipid bilayer patches on the metasurface,” says Altug.

This pioneering AI-powered, metasurface-based biosensor will open up exciting perspectives for studying and unraveling inherently complex biological processes, such as intercellular communication via exosomesand the interaction of nucleic acids and carbohydrates with proteins in gene regulation and neurodegeneration. 

“We imagine that our technology will have applications in the fields of biology, bioanalytics and pharmacology – from fundamental research and disease diagnostics to drug development,” says Altug. 

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

Infrared Metasurface Augmented by Deep Learning for Monitoring Dynamics between All Major Classes of Biomolecules by Aurelian John‐Herpin, Deepthy Kavungal. Lea von Mücke, Hatice Altug. Advanced Materials Volume 33, Issue 14 April 8, 2021 2006054 DOI: https://doi.org/10.1002/adma.202006054 First published: 22 February 2021

This paper is open access.

Superstar engineers and fantastic fiction writers podcast series

The ‘Inventive Podcast’ features the superstar engineers and fantastic fiction writers of the headline. The University of Salford (UK) launched the series on Wednesday, June 23, 2021or International Women in Engineering Day. Here’s more about the series from a June 21, 2021 University of Salford press release (Note: I liked the title so much I ‘borrowed’ it),

Superstar engineers and fantastic fiction writers collaborate on the brand-new Inventive Podcast

The University of Salford has announced the launch of the brand-new Inventive Podcast featuring the incredible stories of engineers whose innovative work is transforming the world we live in.

Professor Trevor Cox, Inventive Host and an Acoustical Engineer from the University of Salford said: “Engineering is so central to our lives, and yet as a subject it’s strangely hidden in plain sight. I came up with idea of Inventive to explore new ways of telling the story of engineering by mixing fact and fiction.”  He went on to comment, “Given the vast number of podcasts out there, it’s surprising how few shows focus on engineering (beyond tech).”

The project is funded by the Engineering and Physical Sciences [Research] Council (EPSRC) and brings together two Schools at the University: Science, Engineering and Environment & Arts, Media and Creative Technology.  The series will debut on Wednesday 23 June [2021], International Women in Engineering Day, with a further with 6 new episodes dropping across the summer.

Over the course of the eleven-episode series, Professor Cox meets incredible Inventive engineers. In the first episode he interviews: electronics engineer, Shrouk el Attar, a refugee and campaigner for LGBT rights, recently awarded the Women’s Engineering Society (WES) Prize for her work in femtech, smart tech that improves the lives of cis women and trans men, at the Institution of Engineering and Technology Young Woman Engineer of the Year Awards 2021; structural engineer Roma Agrawal designed the foundation and spire of London’s The Shard; and chemical engineer Askwar Hilonga who didn’t have access to clean water growing up in his village in Tanzania, but has gone on to win the Africa Prize for Engineering Innovation for his water purification nano filter.

This podcast is not just for engineers and techies! Engineering is typically represented in the media by historical narratives or ‘boy’s toys’ approach – biggest, longest, tallest. We know that has limited appeal, so we set ourselves a challenge to reach a wider audience. Engineering needs to tell better stories with people at the centre. So, we’ve interwoven factual interviews with stories commissioned from fantastic writers: C M Taylor’s piece The Night Builder, is inspired by structural engineer Roma Agrawal and includes a Banksy-like figure who works with concrete. Science Fiction writer Emma Newman’s Healing the Fractured is inspired by engineer Greg Bowie who makes trauma plates to treat broke bones and is set in a dystopian future, reminiscent of Handmaid’s Tale, with the engineer as an unexpected hero.

For more information and to sign-up for the latest episodes go to: www.inventivepodcast.com

I listened to Trevor Cox’s interview for the first and, so far, only Inventive episode, with engineer, Shrouk El-Attar, which includes award-winning writer and poet, Tania Hershman, performing her piece ‘Human Being As Circuit Board, Human Being as Dictionary‘ combining fiction, poetry and non-fiction based on El-Attar’s story. (Check out Shrouk El-Attar’s eponymous website here.)

I recognized one of the upcoming interview subjects, Askwar Hilonga, as his work with water filters in Tanzania has been featured here twice, notably in this June 16, 2015 posting.

Finally Tania Hershman (Twitter: @taniahershman) has an eponymous website here. (Note: In September 2021 she will be leading a 4-week online Science-Flavoured Writing course for the London Lit Lab. A science background isn’t necessary and, if you’re short on cash, there are some options.)