Tag Archives: spider silk

Fashion, sustainability, and the protein threads that bind textiles and cosmetics

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I’m starting with a somewhat enthusiastic overview of the role synthetic biology is playing in the world of clothing and cosmetics in The Scientist and following it up with some stories about fish leather, no synthetic biology involved but all of these stories are about sustainability and fashion and, in one case, cosmetics.

Fashionable synthetic biology

Meenakshi Prabhune’s June 14, 2024 article in The Scientist, in addition to the overview, provides information that explains how some of the work on textiles and leather is being used in the production of cosmetics. She starts with a little history/mythology and then launches into the synthetic biology efforts to produce silk and leather suitable for consumer use, Note: Links have been removed,

Once upon a time, circa 2700 BC in China, empress Xi Ling Shi was enjoying her afternoon tea under a mulberry tree, when a silkworm cocoon fell from the tree into her tea. She noticed that on contact with the hot beverage, the cocoon unraveled into a long silky thread. This happy accident inspired her to acquire these threads in abundance and fashion them into an elegant fabric. 

So goes the legend, according to the writings of Confucius, about the discovery of silk and the development of sericulture in ancient China. Although archaeological evidence from Chinese ruins dates the presence of silk to 8500 years ago, hinting that the royal discovery story was spun just like the silk fabric, one part of the legend rings true.1 The Chinese royals played a pivotal role in popularizing silk as a symbol of status and wealth. By 130 BC, emperors in the Ancient Civilizations across the world desired to be clad in silken garments, paving the Silk Road that opened trade routes from China to the West. 

While silk maintained its high-society status over the next thousands of years, the demand for easy-to-use materials grew among mass consumers. In the early 20th century, textile developers applied their new-found technological prowess to make synthetic materials: petrochemical-based polymer blended textiles with improved durability, strength, and convenience. 

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In their quest to make silk powerful again, not by status but rather by thread strength, scientists turned to an arachnoid. Dragline silk, the thread by which the spider hangs itself from the web, is one of the strongest fibers; its tensile strength—a measure of how much a polymer deforms when strained—is almost thrice that of silkworm silk.2 

Beyond durable fashion garments, tough silk fibers are coveted in parachutes, military protective gear, and automobile safety belts, among other applications, so scientists are keen to pull on these threads. While traditional silk production relies on sericulture, arachnophobes can relax: spider farms are not a thing.

“Spiders make very little silk and are quite territorial. So, the only way to do it is to make microbes that make the protein,” said David Breslauer, cofounder and chief technology officer at Bolt Threads, a bio apparel company. 

For decades, researchers have coaxed microbes into churning their metabolites in large fermentation tanks, which they have harvested to solve dire crises in many areas. For instance, when pharmaceuticals struggled to meet the growing demand for insulin through the traditional methods of extraction from animal pancreas, researchers at Genentech sought the aid of E. coli to generate recombinant insulin for mass production in 1978.3  [emphases mine]

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Prabhune’s June 14, 2024 article notes some difficulties with spider silk, Note: Links have been removed,

… researchers soon realized that producing spider silk in microbes was no easy feat. The spider silk protein, spidroin, is larger than 300 kDa in size—a huge jump from the small 6 kDa recombinant insulin. Bulky proteins impose a heavy metabolic load on the microbes and their production yield tanks. Also, spidroin consists of repeating regions of glycine and alanine amino acids that impart strength and elasticity to the material, but the host microbes struggle with protein folding and overexpression of the corresponding tRNA molecules.4  

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… researchers had gotten close, but they hadn’t been able to synthesize the full spidroin protein. Since the molecular weight of the silk protein correlates with the strength of the silk thread, Zhang [Fuzhong Zhang, a synthetic biologist at Washington University in St. Louis] was determined to produce the entire protein to mimic the silk’s natural properties.5

To achieve this goal without pushing the metabolic limits of the bacteria, Zhang and his team literally broke down the problem. In 2018, they devised a recombinant spidroin by constructing two protein halves with split inteins—peptides known to catalyze ligation between proteins while splicing out their own residues—tagged at their ends. They synthesized the halves in separate E. coli cultures, mixed the two cultures, and ligated the proteins to yielded a recombinant spidroin of 556 kDa—a size that was previously considered unobtainable.6 The resulting silk fiber made from these recombinant spidroins matched the mechanical properties of natural spider silk fiber.

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While synthesizing the high molecular weight protein validated their technical prowess and strategy, Zhang knew that the yield with this approach was going to be unavoidably low. “It was not even enough to make a simple shirt,” he said.

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Zhang and his team did solve the problem of getting a higher yield but that led to another problem, from Prabhune’s June 14, 2024 article,

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Breslauer echoed the importance of this step. He recalled how scaling up was the biggest challenge when he and his cofounder Dan Widmaier, chief executive officer at Bolt Threads, first set up shop in 2009. The duo met during their graduate studies. Breslauer, a material science student at the University of California, Berkeley, was fascinated by spider silk and sought help for synthesizing the protein in microbes. Luckily, he met Widmaier, a synthetic biology graduate student who was optimizing systems to study complex proteins.

When their collaboration to produce recombinant spider silk proteins in yeast yielded promising results, the duo decided to challenge the status quo in the textile industry by commercially producing bio-silk apparel, and Bolt Threads was born. The market transition, however, was not as smooth as the threads they produced. 

“There was so little innovation in the textile space, and brands were really eager to talk about innovation. It felt like there was demand there. Turns out, the desire for storytelling outweighed the desire for actual innovation with those brands,” Breslauer said. “We didn’t realize how adverse [sic] people were going to be to the idea because it was so unfamiliar.”

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Prabhune’s June 14, 2024 article also covers leather and cosmetics, Note: Links have been removed,

David Williamson, a chemist and the chief operations officer at Modern Meadow and his team wanted to separate themselves from the herd. In their quest for sustainable alternatives, they went back to the basic biology and chemistry of the material. As leather is made from animal skin, it is rich in collagen, a structural protein abundant in the extracellular matrix of connective tissues. If the team could produce this primary component protein at scale, they would be able to process it into leather downstream. 

In about 2017, Williamson and his team developed a fermentation-based approach to produce collagen from yeast. While they achieved scalable production, there was one small hiccup. The protein properties of collagen alone did not yield the mechanical properties they needed for their leather-like material. 

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The team went to the drawing board and analyzed the amino acid residues that contributed to collagen’s characteristics to look for a substitute protein. They found an alternative that had the desirable functional elements of collagen but was also sustainable and cost effective for industrial scale up: soy protein isolate. While tinkering with their recipes, they found the perfect combination for material strength by mixing in a bio-based polyurethane polymer with the protein to yield a refined bioalloy called Bio-VERA. 

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As natural textiles are derived from animal skin, hair, or proteins, it is no surprise that many synthetic biologists in the textile space have also found a niche in cosmetics. Even as the Modern Meadow team transitioned away from their protein fermentation strategies to innovate Bio-VERA, they realized that they could still apply their expertise in skincare. While leathery is not an adjective one desires to associate with skin, collagen is an integral component in both. “When our bodies make collagen and build our extracellular matrices, one of the first proteins that they deposit is type three collagen. So, you can think of type three collagen almost like the structure or scaffold of a building,” explained Williamson.

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To cater to the increasing demand for solutions to achieve younger looking skin, Williamson and his team engineered a recombinant collagen type three protein containing part of the protein sequence that is rich in binding domains for fibroblast interactions.9,10  “After you expose the extracellular matrix to this protein, it stimulates the fibroblasts to make more type three collagen. That type three collagen lays down type one collagen and elastin and fibronectin in a way that actually helps to turn back time, so to speak, to increase the ratio of type three collagen relative to type one collagen,” Williamson said. 

The Modern Meadow team are not the only ones to weave their textile strands into cosmetic applications. When Artur Cavaco-Paulo, a biological engineer at the University of Minho [Portugal], was studying wool fibers, he was struck by their structural similarities to human hair. “We decided that it would be a really good idea to transfer some of the knowledge that we had in wool textiles to human hair,” said Cavaco-Paulo. Particularly, he was interested in investigating solutions to fix hair strands damaged by highly alkaline chemical products. 

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Over the next few years, Cavaco-Paulo developed […] shortlisted peptides into the K18 peptide product, which is now part of a commercially available leave-in conditioner. Cavaco-Paulo serves as the chief scientific officer at the biotech company K18. 

Although he started his career with textile research, Cavaco-Paulo favors the cosmetics sector with regards to returns on research and technology investment. “The personal care market is much more accustomed to innovation and has a much better and more fluid pipeline on innovation,” seconded Breslauer. “Whereas, [in] apparel, you really have to twist arms to get people to work with your material.” Bolt Threads ventured into the personal care space when Breslauer and his team serendipitously stumbled upon an alternative use for one of their textile proteins. 

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While it’s not mentioned in Prabhune’s June 14, 2024 article, sustainability is mentioned on two of the company websites,

Bolt Threads

Bolt Threads is a material solutions company. With nature as our inspiration, we invent cutting-edge materials for the fashion and beauty industries to put us on a path toward a more sustainable future.

Through innovative collaborations with world-class brands and supply chain partners, we are on a mission to create way better materials for a way better world. Join us.

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Modern Meadow

Modern Meadow is a climate-tech pioneer creating the future of materials through innovations in biology and material science.

​Our bio-materials technology platform with nature-inspired protein solutions delivers better performance, sustainability, scalability, and cost while reducing reliance on petrochemical and animal-based inputs.​

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K18 has not adopted a ‘sustainability’ approach to marketing its hair care products.

Sustainability without synthetic biology: fish leather

In a January 3, 2022 posting I featured fish leather/skin in a story about the “Futures exhibition/festival” held at the Smithsonian Institute from November 20, 2021 to July 6, 2022.

Before getting to Futures, here’s a brief excerpt from a June 11, 2021 Smithsonian Magazine exhibition preview article by Gia Yetikyel about one of the contributors, Elisa Palomino-Perez (Note: A link has been removed),

Elisa Palomino-Perez sheepishly admits to believing she was a mermaid as a child. Growing up in Cuenca, Spain in the 1970s and ‘80s, she practiced synchronized swimming and was deeply fascinated with fish. Now, the designer’s love for shiny fish scales and majestic oceans has evolved into an empowering mission, to challenge today’s fashion industry to be more sustainable, by using fish skin as a material.

Luxury fashion is no stranger to the artist, who has worked with designers like Christian Dior, John Galliano and Moschino in her 30-year career. For five seasons in the early 2000s, Palomino-Perez had her own fashion brand, inspired by Asian culture and full of color and embroidery. It was while heading a studio for Galliano in 2002 that she first encountered fish leather: a material made when the skin of tuna, cod, carp, catfish, salmon, sturgeon, tilapia or pirarucu gets stretched, dried and tanned.

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The history of using fish leather in fashion is a bit murky. The material does not preserve well in the archeological record, and it’s been often overlooked as a “poor person’s” material due to the abundance of fish as a resource. But Indigenous groups living on coasts and rivers from Alaska to Scandinavia to Asia have used fish leather for centuries. Icelandic fishing traditions can even be traced back to the ninth century. While assimilation policies, like banning native fishing rights, forced Indigenous groups to change their lifestyle, the use of fish skin is seeing a resurgence. Its rise in popularity in the world of sustainable fashion has led to an overdue reclamation of tradition for Indigenous peoples.

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Brendan Jones provides an update of sorts in his Alaska-forward take in his February 22, 2024 article “Fish Leather Is Incredibly Strong and Beautiful. Can Makers ‘Scale Up’? Meet artisans in Alaska and BC who are sustaining, and advancing, an ancient art.” for The Tyee,

Fish leather artist June Pardue began her journey into the craft not knowing where to start. Which was a problem, considering that she had been given the job of demonstrating for tourists how to tan fish skin at the Alaska Native Heritage Center in Anchorage. “I couldn’t find anyone to teach me,” Pardue said with a laugh.

“One day a guy from Mississippi noticed me fumbling around. He kindly waited until everyone had left. Then he said, ‘Do you want me to share my grandpappy’s recipe for tanning snake skins?’”

His cocktail of alcohol and glycerin allowed her to soften the skins — as tourists looked on — for future use in clothing and bags. This worked fine until she began to grow uncomfortable dumping toxins down the drain. Now she uses plant-based tannins like those found in willow branches after the season’s first snowmelt. She harvests the branches gingerly, allowing the trees to survive for the next generation of fish tanners.

Pardue, who teaches at the University of Alaska, was born on Kodiak Island, off the southern coast of the state, in Old Harbor village. Alutiiq and Iñupiaq, she was raised in Akhiok, population about 50, and Old Harbor.

Following her bumpy start at the heritage center, Pardue has since gone on to become one of Alaska’s and Canada’s most celebrated instructors and practitioners in the field of fish leather, lighting the way for others in Alaska and Canada.

Among the people Pardue has advised is CEO and founder of 7 Leagues tannery Tasha Nathanson, who is based in Vancouver. She met with Pardue to share her idea of creating a business built on making fish leather into boots and other items for a large customer base.

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Before making her move to open a business, Nathanson spent a year running the numbers, she said. In 2022, the global fish leather market was valued at US$36.22 million. As fish tanneries open their doors and fashion houses take notice, the number is expected to grow 16 per cent annually, topping $100 million by 2030.

“Salmon certainly don’t come to mind when you think of tanning, but people are catching on,” said Judith Lehmann, a Sitka-based expert in fish leather, who took Pardue’s class. (The Tyee reached Lehmann in Panama, where she was experimenting with skins of bonito and mahi mahi.)

Growing numbers of buyers are willing to pay for not only the beauty but also the remarkable durability fish leather can offer. California-based eco-fashion designer Hailey Harmon’s company Aitch Aitch sells the Amelia, a teal backpack made of panelled salmon leather, for $795.

One company in France has started to collect fish skins from restaurants — material that would otherwise end up in trash cans — to make luxury watch bands and accessories. Designers like Prada, Louis Vuitton and Christian Dior have incorporated fish leather into their lines. Even Nike introduced running shoes made of perch skin.

Whether they know it or not, today’s trendsetters are rooted in ancient history. “People have been working with fish skins for thousands of years,” Pardue said. “Ireland, Iceland, Norway, China, Japan — it’s an age-old practice.”

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“On a molecular level, fibres in fish leather are cross-hatched, as opposed to cow leather, which is just parallel,” Nathanson explained. “So, pound for pound, this leather is stronger, which is great for shoes. And it’s more available, and eco-conscious. It’s a win across the board.”

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Jones’s February 22, 2024 article has some wonderful embedded pictures and Beth Timmins’s May 1, 2019 article for the BBC (British Broadcasting Corporation), while a little dated, offers more information about the international scene.

Synthetic biology is a scientific practice that I find disconcerting at times. That said, I’m glad to see more work on sustainable products however they are derived. On that note I have a couple of recent stories:

  • “Three century long development of a scientific idea: body armor made from silk” is the title of my July 11, 2024 posting
  • “Grown from bacteria: plastic-free vegan leather that dyes itself” is the title of my June 26, 2024 posting

Enjoy!

Three century long development of a scientific idea: body armor made from silk

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Credit: Unsplash/CC0 Public Domain [downloaded from https://phys.org/news/2024-04-body-armor-silk-apparently-edge.html]

Lloyd Strickland’s (professor of Philosophy and Intellectual History, Manchester Metropolitan University) fascinating April 9, 2024 essay on The Conversation (h/t April 10, 2024 news item on phys.org) illustrates the long and winding road to scientific and technological discoveries, Note: Links have been removed,

Separate teams of Chinese and American scientists are reported to be developing body armour using the silk from genetically modified silkworms. The researchers modified the genes of silkworms to make them produce spider silk instead of their own silk.

Harnessing the properties of spider silk has been a longstanding aim because the material is as strong as steel, yet also highly elastic. However, the idea of using silk to make bulletproof vests is not a new idea. Instead, it goes back centuries.

The invention of the silk bulletproof vest is often credited to the American physician George Emory Goodfellow (1855–1910), following his observation that silk was impenetrable to bullets.

But the idea was in fact proposed more than two centuries earlier by the German polymath Gottfried Wilhelm Leibniz (1646–1716), best known as inventor of calculus and binary arithmetic. …

You’ll notice it’s almost two centuries between the idea being proposed and someone working out a way to make a silk bulletproof vest. First, Liebniz (from Strickland’s April 9, 2024 essay), Note: Links have been removed,

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In one of these little-known writings, unassumingly entitled “Plan for a military manufacturing process”, Leibniz sought to identify a material suitable for making a lightweight, flexible, bulletproof fabric. He briefly considered metal wires, layered metal sheets, and layered “goldbeater’s skin”, which is a material made from ox intestine. However, he devoted most of his attention to silk.

Whereas Goodfellow had observed the impenetrability of silk by bullets, Leibniz never had. Instead, he thought silk was the most promising material for a bulletproof fabric due to being lightweight, flexible, and strong. “Of all the materials we use for fabrics, and which can be obtained in quantity, there is nothing firmer than a silk thread,” he wrote.

Noting that silk was never firmer than in the cocoon, “where the silk is still gathered in the way that nature produced it”, Leibniz proposed making a fabric formed of silkworm cocoons tightly pressed together with a little glue.

He realised that while such a sheet could not easily be pierced, due to the tightly-woven silk in the cocoons, it would be prone to tearing where one cocoon met the next. Thus, he inferred that a bullet would not make a hole in the fabric, but instead tear whatever cocoon it hit from the surrounding ones, and drive it into the body, similar to what Goodfellow would observe with the silk handkerchief two centuries later.

Leibniz’s solution to the tearing problem was to propose layering sheets of pressed silkworm cocoons on top of each other. He illustrated this with a rudimentary diagram of a row of circles stacked on top of one another in a lattice arrangement, where a small interstice is left between adjoining circles.

Layering cocoons in such a hexagonal packing arrangement ensures that the weak parts of one layer are covered by the strong parts of another. This way, the fabric would not tear or be pierced when hit by a bullet. The result, Leibniz claimed, would be a fabric suitable for covering almost the whole body, especially if it was made to be oversized, affording the wearer freedom of movement.

Leibniz never realised his proposal to create bulletproof clothing using silk.

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Strickland’s April 9, 2024 essay offers more about how Goodfellow’s field observations led to the invention of the first silk bulletproof vest by a Catholic priest.

Scott Burton’s undated article for bodyarmornews.com on spider silk and bulletproof body armour offers information about current efforts by US and Chinese scientists to incorporate spider proteins by gene editing silkworms capable of producing enough hybrid silk for enhanced body armour.

A century later, what appears to be the latest breakthrough was announced in a September 24, 2023 news item on chinadaily.com (and noted in Burton’s article),

Chinese scientists have developed the first whole full-length spider silk fiber obtained from genetically-engineered silkworms, exhibiting a six-fold toughness when compared to a bulletproof vest.

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The results pave the way for spider silk’s commercialization as a sustainable substitute for synthetic fibers, and it can be used in making surgical sutures and comfortable bulletproof vests, according to the study.

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

High-strength and ultra-tough whole spider silk fibers spun from transgenic silkworms by Junpeng Mi, Yizhong Zhou, Sanyuan Ma, Xingping Zhou, Shouying Xu, Yuchen Yang, Yuan Sun, Qingyou Xia, Hongnian Zhu, Suyang Wang, Luyang Tian, Qing Men. Matter Volume 6, ISSUE 10, P3661-3683, October 04, 2023 DOI: https://doi.org/10.1016/j.matt.2023.08.013 First published online: September 20, 2023

This paper is behind a paywall.

Winter jacket made with ‘brewed protein’ and enabled by synthetic biology

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It’s called a ‘Moon Parka’,

[downloaded from https://sp.spiber.jp/en/tnfsp/mp/]

Adele Peters in her October 31, 2019 article for Fast Company describes the technology used to make this jacket,

A typical waterproof winter jacket is made with nylon—a material that, like other plastics, is made from petroleum. But a new limited-edition jacket from The North Face Japan uses something called “brewed protein” instead. It’s a material inspired by spider silk that is fermented in giant vats, the same way that breweries make beer.

It’s one of the first uses of a material produced by the Japanese startup Spiber, a company that has spent more than a decade developing a new process to make high-performance textiles and other products that don’t rely on fossil fuels, animals, or natural fibers like cotton, all of which have environmental issues. …

The company designs genes that code for a specific protein—the first was an exact replica of natural spider silk, known for its extreme strength—and then introduces the genes into microorganisms that can produce the protein efficiently. Inside giant tanks, the microorganisms are fed sugar, grow and multiply, and produce the protein through fermentation. …

Spiber first started collaborating with Goldwin, a Japanese outdoor brand that owns the Japanese rights to The North Face, in 2015, and created an early prototype of a jacket then. But it quickly realized that an exact replica of spider silk wouldn’t work well for the application; the material sucks up water, and the jacket needed to be waterproof.

“We spent the last four years going back to the drawing board, redesigning our protein molecule—the very order of the amino acids in the molecule,” says Meyer [Daniel Meyer, Spiber’s head of corporate global marketing]. “And we created our own hydrophobic [water repellent] version of spider silk. It’s inspired by natural spider silk, but we have made our own design changes such that it would be more hydrophobic and meet the performance requirements of The North Face Japan.”

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The jacket is available for purchase but only by a lottery, which has now closed. According to Peters, a large, commercial production facility is being built in Thailand so that at some point a Moon Parka will be affordable. For reference, the lottery jackets were priced at ¥150,000 (about $1,377 US).

You can find Spiber here in mid-March [2020] according to the homepage.

Spider glue

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Caption: An orb spider, glue-maker extraordinaire, at work on a web. Credit: The University of Akron

Scientists are taking inspiration from spiders in their quest to develop better adhesives. (Are they abandoning the gecko? Usually when scientists study adhesiveness, there’s talk of geckos. From a June 5, 2018 news item on ScienceDaily,

Ever wonder why paint peels off the wall during summer’s high humidity? It’s the same reason that bandages separate from skin when we bathe or swim.

Interfacial water, as it’s known, forms a slippery and non-adhesive layer between the glue and the surface to which it is meant to stick, interfering with the formation of adhesive bonds between the two.

Overcoming the effects of interfacial water is one of the challenges facing developers of commercial adhesives.

To find a solution, researchers at The University of Akron (UA) are looking to one of the strongest materials found in nature: spider silk.

The sticky glue that coats the silk threads of spider webs is a hydrogel, meaning it is full of water. One would think, then, that spiders would have difficulty catching prey, especially in humid conditions — but they do not. In fact, their sticky glue, which has been a subject of intensive research for years, is one of the most effective biological glues in all of nature.

A June 4, 2018 University of Akron news release (also on EurekAlert published on June 5, 2018), which originated the news item, provides more detail,

So how is spider glue able to stick in highly humid conditions?

That question was the subject of investigation by UA graduate students Saranshu Singla, Gaurav Amarpuri and Nishad Dhopatkar, who have been working with Dr. Ali Dhinojwala, interim dean of the College of Polymer Science and Polymer Engineering, and Dr. Todd Blackledge, professor of biology in the Integrated Bioscience program. Both professors are principal investigators in UA’s Biomimicry Research Innovation Center [BRIC], which specializes in emulating biological forms, processes, patterns and systems to solve technical challenges.

The team’s findings, which may provide the clue to developing stronger commercial adhesives, can be read in a paper recently published in the journal Nature Communications.

Singla and her colleagues set out to examine the secret behind the success of the common orb spider (Larinioides cornutus) glue and uncover how it overcomes the primary obstacle of achieving good adhesion in the humid conditions where water could be present between the glue and the target surface.

To investigate the processes involved, the team took orb spider glue, set it on sapphire substrate, then examined it using a combination of interface-sensitive spectroscopy and infrared spectroscopy.

Spider glue is made of three elements: two specialized glycoproteins, a collection of low molecular mass organic and inorganic compounds (LMMCs), and water. The LMMCs are hygroscopic (water-attracting), which keeps the glue soft and tacky to stick.

Singla and her team discovered that these glycoproteins act as primary binding agents to the surface. Glycoprotein-based glues have been identified in several other biological glues, such as fungi, algae, diatoms, sea stars, sticklebacks and English ivy.

But why doesn’t the water present in the spider glue interfere with the adhesive contact the way it does with most synthetic adhesives?

The LMMCs, the team concluded, perform a previously unknown function of sequestering interfacial water, preventing adhesive failure.

Singla and colleagues determined that it is the interaction of glycoproteins and LMMCs that governs the adhesive quality of the glue produced, with the respective proportions varying across species, thus optimizing adhesive strength to match the relative humidity of spider habitat.

“The hygroscopic compounds – known as water-absorbers – in spider glue play a previously unknown role in moving water away from the boundary, thereby preventing failure of spider glue at high humidity,” explained Singla.

The ability of the spider glue to overcome the problem of interfacial water by effectively absorbing it is the key finding of the research, and the one with perhaps the strongest prospect for commercial development.

“Imagine a paint that is guaranteed for life, come rain or shine,” Singla remarked.

All thanks to your friendly neighborhood spider glue.

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

Hygroscopic compounds in spider aggregate glue remove interfacial water to maintain adhesion in humid conditions by Saranshu Singla, Gaurav Amarpuri, Nishad Dhopatkar, Todd A. Blackledge, & Ali Dhinojwala. Nature Communicationsvolume 9, Article number: 1890 (2018) Published 22 May 2018 DOI: https://doi.org/10.1038/s41467-018-04263-z

This paper is open access.

Australian peacock spiders, photonic nanostructures, and making money

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Researcher Bor-Kai Hsiung’s work has graced this blog before but the topic was tarantulas and their structural colour. This time, it’s all about Australian peacock spiders and their structural colour according to a December 22, 2017 news item on ScienceDaily,

Even if you are arachnophobic, you probably have seen pictures or videos of Australian peacock spiders (Maratus spp.). These tiny spiders are only 1-5 mm long but are famous for their flamboyant courtship displays featuring diverse and intricate body colorations, patterns, and movements.

The spiders extremely large anterior median eyes have excellent color vision and combine with their bright colors to make peacock spiders cute enough to cure most people of their arachnophobia. But these displays aren’t just pretty to look at, they also inspire new ways for humans to produce color in technology.

One species of peacock spider — the rainbow peacock spider (Maratus robinsoni) is particularly neat, because it showcases an intense rainbow iridescent signal in males’ courtship displays to the females. This is the first known instance in nature of males using an entire rainbow of colors to entice females. Dr. Bor-Kai Hsiung led an international team of researchers from the US (UAkron, Cal Tech, UC San Diego, UNL [University of Nebraska-Lincoln]), Belgium (Ghent University), Netherlands (UGroningen), and Australia to discover how rainbow peacock spiders produce this unique multi-color iridescent signal.

A December 22, 2017 Ghent University (Belgium) press release on Alpha Galileo, which originated the news item, provides more technical detail,

Using a diverse array of research techniques, including light and electron microscopy, hyperspectral imaging, imaging scatterometry, nano 3D printing and optical modeling, the team found the origin of this intense rainbow iridescence emerged from specialized abdominal scales of the spiders. These scales have an airfoil-like microscopic 3D contour with nanoscale diffraction grating structures on the surface.

The interaction between the surface nano-diffraction grating and the microscopic curvature of the scales enables separation and isolation of light into its component wavelengths at finer angles and smaller distances than are possible with current manmade engineering technologies.

Inspiration from these super iridescent scales can be used to overcome current limitations in spectral manipulation, and to further reduce the size of optical spectrometers for applications where fine-scale spectral resolution is required in a very small package, notably instruments on space missions, or wearable chemical detection systems. And it could have a wide array of implications to fields ranging from life sciences and biotechnologies to material sciences and engineering.

Here’s a video of an Australian rainbow peacock spider,

Here’s more from the YouTube description published on April 13, 2017 by Peacockspiderman,

Scenes of Maratus robinsoni, a spider Peter Robinson discovered and David Hill and I named it after him in 2012. You can read our description on pages 36-41 in Peckhamia 103.2, which can be downloaded from the Peckhamia website http://peckhamia.com/peckhamia_number…. This is one of the two smallest species of peacock spider (2.5 mm long) and the only spider we know of in which colour changes occur every time it moves, this video was created to document this. Music: ‘Be Still’ by Johannes Bornlöf licensed through my MCN ‘Brave Bison’ from ‘Epidemic Sound’ For licensing inquiries please contact Brave Bison licensing@bravebison.io

The University of California at San Diego also published a December 22, 2017 news release about this work, which covers some of the same ground while providing a few new tidbits of information,

Brightly colored Australian peacock spiders (Maratus spp.) captivate even the most arachnophobic viewers with their flamboyant courtship displays featuring diverse and intricate body colorations, patterns, and movements – all packed into miniature bodies measuring less than five millimeters in size for many species. However, these displays are not just pretty to look at. They also inspire new ways for humans to produce color in technology.

One species of peacock spider – the rainbow peacock spider (Maratus robinsoni) – is particularly impressive, because it showcases an intense rainbow iridescent signal in males’ courtship displays to females. This is the first known instance in nature of males using an entire rainbow of colors to entice females to mate. But how do males make their rainbows? A new study published in Nature Communications looked to answer that question.

Figuring out the answers was inherently interdisciplinary so Bor-Kai Hsiung, a postdoctoral scholar at Scripps Institution of Oceanography at the University of California San Diego, assembled an international team that included biologists, physicists and engineers. Starting while he was a Ph.D. student at The University of Akron under the mentorship of Todd Blackledge and Matthew Shawkey, the team included researchers from UA, Scripps Oceanography, California Institute of Technology, and University of Nebraska-Lincoln, the University of Ghent in Belgium, University of Groningen in Netherlands, and Australia to discover how rainbow peacock spiders produce this unique iridescent signal.

The team investigated the spider’s photonic structures using techniques that included light and electron microscopy, hyperspectral imaging, imaging scatterometry and optical modeling to generate hypotheses about how the spider’s scale generate such intense rainbows. The team then used cutting-edge nano 3D printing to fabricate different prototypes to test and validate their hypotheses. In the end, they found that the intense rainbow iridescence emerged from specialized abdominal scales on the spiders. These scales combine an airfoil-like microscopic 3D contour with nanoscale diffraction grating structures on the surface. It is the interaction between the surface nano-diffraction grating and the microscopic curvature of the scales that enables separation and isolation of light into its component wavelengths at finer angles and smaller distances than are possible with current engineering technologies.

“Who knew that such a small critter would create such an intense iridescence using extremely sophisticated mechanisms that will inspire optical engineers,” said Dimitri Deheyn, Hsuing’s advisor at Scripps Oceanography and a coauthor of the study.

For Hsiung, the finding wasn’t quite so unexpected.

“One of the main questions that I wanted to address in my Ph.D. dissertation was ‘how does nature modulate iridescence?’ From a biomimicry perspective, to fully understand and address a question, one has to take extremes from both ends into consideration. I purposefully chose to study these tiny spiders with intense iridescence after having investigated the non-iridescent blue tarantulas,” said Hsiung.

The mechanism behind these tiny rainbows may inspire new color technology, but would not have been discovered without research combining basic natural history with physics and engineering, the researchers said.

“Nanoscale 3D printing allowed us to experimentally validate our models, which was really exciting,” said Shawkey. “We hope that these techniques will become common in the future.”

“As an engineer, what I found fascinating about these spider structural colors is how these long evolved complex structures can still outperform human engineering,” said Radwanul Hasan Siddique, a postdoctoral scholar at Caltech and study coauthor. “Even with high-end fabrication techniques, we could not replicate the exact structures. I wonder how the spiders assemble these fancy structural patterns in the first place!”

Inspiration from these super iridescent spider scales can be used to overcome current limitations in spectral manipulation, and to reduce the size of optical spectrometers for applications where fine-scale spectral resolution is required in a very small package, notably instruments on space missions, or wearable chemical detection systems.

In the end, peacock spiders don’t just produce nature’s smallest rainbows.They could also have implications for a wide array of fields ranging from life sciences and biotechnologies to material sciences and engineering.

Before citing the paper and providing a link, here’s a story by Robert F. Service for Science (October 18, 2017 article*) magazine about attempts to capitalize on ‘spider technology’, in this case spider silk,

The hype over spider silk has been building since 1710. That was the year François Xavier Bon de Saint Hilaire, president of the Royal Society of Sciences in Montpellier, France, wrote to his colleagues, “You will be surpriz’d to hear, that Spiders make a Silk, as beautiful, strong and glossy, as common Silk.” Modern pitches boast that spider silk is five times stronger than steel yet more flexible than rubber. If it could be made into ropes, a macroscale web would be able to snare a jetliner.

The key word is “if.” Researchers first cloned a spider silk gene in 1990, in hopes of incorporating it into other organisms to produce the silk. (Spiders can’t be farmed like silkworms because they are territorial and cannibalistic.) Today, Escherichia coli bacteria, yeasts, plants, silkworms, and even goats have been genetically engineered to churn out spider silk proteins, though the proteins are often shorter and simpler than the spiders’ own. Companies have managed to spin those proteins into enough high-strength thread to produce a few prototype garments, including a running shoe by Adidas and a lightweight parka by The North Face. But so far, companies have struggled to mass produce these supersilks.

Some executives say that may finally be about to change. One Emeryville, California-based startup, Bolt Threads, says it has perfected growing spider silk proteins in yeast and is poised to turn out tons of spider silk thread per year. In Lansing, Michigan, Kraig Biocraft Laboratories says it needs only to finalize negotiations with silkworm farms in Vietnam to produce mass quantities of a combination spider/silkworm silk, which the U.S. Army is now testing for ballistics protection. …

I encourage you to read Service’s article in its entirety if the commercialization prospects for spider silk interest you as it includes gems such as this,

Spider silk proteins are already making their retail debut—but in cosmetics and medical devices, not high-strength fibers. AMSilk grows spider silk proteins in E. coli and dries the purified protein into powders or mixes it into gels, for use as additives for personal care products, such as moisture-retaining skin lotions. The silk proteins supposedly help the lotions form a very smooth, but breathable, layer over the skin. Römer says the company now sells tons of its purified silk protein ingredients every year.

…

Finally, here’s a citation for and a link to the paper about Australian peacock spiders and nanophotonics,

Rainbow peacock spiders inspire miniature super-iridescent optics by Bor-Kai Hsiung, Radwanul Hasan Siddique, Doekele G. Stavenga, Jürgen C. Otto, Michael C. Allen, Ying Liu, Yong-Feng Lu, Dimitri D. Deheyn, Matthew D. Shawkey, & Todd A. Blackledge. Nature Communications 8, Article number: 2278 (2017) doi:10.1038/s41467-017-02451-x Published online: 22 December 2017

This paper is open access.

As for Bor-Kai Hsiung’s other mentions here:

How tarantulas get blue (December 7, 2015 posting)

Noniridescent photonics inspired by tarantulas (October 19, 2016 posting)

More on the blue tarantula noniridescent photonics (December 28, 2016 posting)

*Link to Robert F. Service’s October 18, 2017 article added July 19, 2024

Making spider silk stronger by feeding graphene and carbon nanotubes to spiders

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Spider silk is already considered a strong and tough material but now scientists have found a way to enhance those properties. From an August 15, 2017 Institute of Physics Publishing press release (also on EurekAlert),

…  researchers in Italy and the UK have found a way to make Spidey’s silk a lot stronger, using various different spider species and carbon nanotubes or graphene.

The research team, led by Professor Nicola Pugno at the University of Trento, Italy, succeeded in having their spiders produce silk with up to three times the strength and ten times the toughness of the regular material.

Their discovery, published today in the journal 2D Materials, could pave the way for a new class of bionicomposites, with a wide variety of uses.

Professor Pugno said: “Humans have used silkworm silks widely for thousands of years, but recently research has focussed on spider silk, as it has extremely promising mechanical properties. It is among the best spun polymer fibres in terms of tensile strength, ultimate strain, and especially toughness, even when compared to synthetic fibres such as Kevlar.

“We already know that there are biominerals present in in the protein matrices and hard tissues of insects, which gives them high strength and hardness in their jaws, mandibles and teeth, for example. So our study looked at whether spider silk’s properties could be ‘enhanced’ by artificially incorporating various different nanomaterials into the silk’s biological protein structures.”

To do this, the team exposed three different spider species to water dispersions containing carbon nanotubes or graphene.

After collecting the spiders’ silk, the team tested its tensile strength and toughness.

Professor Pugno said: “We found that the strongest silk the spiders spun had a fracture strength up to 5.4 gigapascals (GPa), and a toughness modulus up to 1,570 joules per gram (J/g). Normal spider silk, by comparison, has a fracture strength of around 1.5 GPa and a toughness modulus of around 150 J/g.

“This is the highest fibre toughness discovered to date, and a strength comparable to that of the strongest carbon fibres or limpet teeth. These are still early days, but our results are a proof of concept that paves the way to exploiting the naturally efficient spider spinning process to produce reinforced bionic silk fibres, thus further improving one of the most promising strong materials.

“These silks’ high toughness and resistance to ultimate strain could have applications such as parachutes.”

“Furthermore, this process of the natural integration of reinforcements in biological structural materials could also be applied to other animals and plants, leading to a new class of “bionicomposites” for innovative applications.”

Remember this? “You are what you eat.” If you’ve ever had doubts about that saying, these spiders should be laying them to rest.

Sadly, this news release doesn’t explain much about the decision to feed the spiders graphene or carbon nanotubes, which are identical other than in their respective shapes (sheet vs tube)  and whether those shapes did or did not affect the strength of the silk.

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

Spider silk reinforced by graphene or carbon nanotubes by Emiliano Lepore, Federico Bosia, Francesco Bonaccorso, Matteo Bruna, Simone Taioli, Giovanni Garberoglio, Andrea C Ferrari, and Nicola Maria Pugno. 2D Materials, Volume 4, Number 3 DOI: https://doi.org/10.1088/2053-1583/aa7cd3 Published 14 August 2017

© 2017 IOP Publishing Ltd

This paper is behind a paywall.

Pugno was most recently mentioned here in a May 29, 2015 posting where he was listed as an author for a paper on synthesizing spider silk. Prior to 2015 I was familiar with Pugno’s name due to his work on adhesiveness in geckos.

Antibiotic synthetic spider silk

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I have a couple of questions, what is ‘click’ chemistry and how does a chance meeting lead to a five-year, interdisciplinary research project on synthetic spider silk? From a Jan. 4, 2017 news item on ScienceDaily,

A chance meeting between a spider expert and a chemist has led to the development of antibiotic synthetic spider silk.

After five years’ work an interdisciplinary team of scientists at The University of Nottingham has developed a technique to produce chemically functionalised spider silk that can be tailored to applications used in drug delivery, regenerative medicine and wound healing.

The Nottingham research team has shown for the first time how ‘click-chemistry’ can be used to attach molecules, such as antibiotics or fluorescent dyes, to artificially produced spider silk synthesised by E.coli bacteria. The research, funded by the Biotechnology and Biological Sciences Research Council (BBSRC) is published today in the online journal Advanced Materials.

A Jan. 3, 2016 University of Nottingham press release (also on EurekAlert), which originated the news item, provides a few more details about ‘click’ chemistry (not enough for me) and more information about the research,

The chosen molecules can be ‘clicked’ into place in soluble silk protein before it has been turned into fibres, or after the fibres have been formed. This means that the process can be easily controlled and more than one type of molecule can be used to ‘decorate’ individual silk strands.

Nottingham breakthrough

In a laboratory in the Centre of Biomolecular Sciences, Professor Neil Thomas from the School of Chemistry in collaboration with Dr Sara Goodacre from the School of Life Sciences, has led a team of BBSRC DTP-funded PhD students starting with David Harvey who was then joined by Victor Tudorica, Leah Ashley and Tom Coekin. They have developed and diversified this new approach to functionalising ‘recombinant’ — artificial — spider silk with a wide range of small molecules.

They have shown that when these ‘silk’ fibres are ‘decorated’ with the antibiotic levofloxacin it is slowly released from the silk, retaining its anti-bacterial activity for at least five days.

Neil Thomas, a Professor of Medicinal and Biological Chemistry, said: “Our technique allows the rapid generation of biocompatible, mono or multi-functionalised silk structures for use in a wide range of applications. These will be particularly useful in the fields of tissue engineering and biomedicine.”

Remarkable qualities of spider silk

Spider silk is strong, biocompatible and biodegradable. It is a protein-based material that does not appear to cause a strong immune, allergic or inflammatory reaction. With the recent development of recombinant spider silk, the race has been on to find ways of harnessing its remarkable qualities.

The Nottingham research team has shown that their technique can be used to create a biodegradable mesh which can do two jobs at once. It can replace the extra cellular matrix that our own cells generate, to accelerate growth of the new tissue. It can also be used for the slow release of antibiotics.

Professor Thomas said: “There is the possibility of using the silk in advanced dressings for the treatment of slow-healing wounds such as diabetic ulcers. Using our technique infection could be prevented over weeks or months by the controlled release of antibiotics. At the same time tissue regeneration is accelerated by silk fibres functioning as a temporary scaffold before being biodegraded.”

The medicinal properties of spider silk recognised for centuries.

The medicinal properties of spider silk have been recognised for centuries but not clearly understood. The Greeks and Romans treated wounded soldiers with spider webs to stop bleeding. It is said that soldiers would use a combination of honey and vinegar to clean deep wounds and then cover the whole thing with balled-up spider webs.

There is even a mention in Shakespeare’s Midsummer Night’s Dream: “I shall desire you of more acquaintance, good master cobweb,” the character ‘Bottom’ said. “If I cut my finger, I shall make bold of you.”

The press release goes on to describe the genesis of the project and how this multidisciplinary team was formed in more detail,

The idea came together at a discipline bridging university ‘sandpit’ meeting five years ago. Dr Goodacre says her chance meeting at that event with Professor Thomas proved to be one of the most productive afternoons of her career.

Dr Goodacre, who heads up the SpiderLab in the School of Life Sciences, said: “I got up at that meeting and showed the audience a picture of some spider silk. I said ‘I want to understand how this silk works, and then make some.’

“At the end of the session Neil came up to me and said ‘I think my group could make that.’ He also suggested that there might be more interesting ‘tweaks’ one could make so that the silk could be ‘decorated’ with different, useful, compounds either permanently or which could be released over time due to a change in the acidity of the environment.”

The approach required the production of the silk proteins in a bacterium where an amino acid not normally found in proteins was included. This amino acid contained an azide group which is widely used in ‘click’ reactions that only occur at that position in the protein. It was an approach that no-one had used before with spider silk — but the big question was — would it work?

Dr Goodacre said: “It was the start of a fascinating adventure that saw a postdoc undertake a very preliminary study to construct the synthetic silks. He was a former SpiderLab PhD student who had previously worked with our tarantulas. Thanks to his ground work we showed we could produce the silk proteins in bacteria. We were then joined by David Harvey, a new PhD student, who not only made the silk fibres, incorporating the unusual amino acid, but also decorated it and demonstrated its antibiotic activity. He has since extended those first ideas far beyond what we had thought might be possible.”

David Harvey’s work is described in this paper but Professor Thomas and Dr Goodacre say this is just the start. There are other joint SpiderLab/Thomas lab students working on uses for this technology in the hope of developing it further.

David Harvey, the lead author on this their first paper, has just been awarded his PhD and is now a postdoctoral researcher on a BBSRC follow-on grant so is still at the heart of the research. His current work is focused on driving the functionalised spider silk technology towards commercial application in wound healing and tissue regeneration.

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

Antibiotic Spider Silk: Site-Specific Functionalization of Recombinant Spider Silk Using “Click” Chemistry by David Harvey, Philip Bardelang, Sara L. Goodacre, Alan Cockayne, and Neil R. Thomas. Advanced Materials DOI: 10.1002/adma.201604245 Version of Record online: 28 DEC 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

I imagine Mr. Cockayne’s name has led to much teasing over the years. People who have names with that kind of potential tend to either change them or double down and refuse to compromise.

Spider silk as a bio super-lens

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Bangor University (Wales, UK) is making quite the impact these days. I’d never heard of the institution until their breakthrough with nanobeads (Sept. 7, 2016 posting) to break through a resolution barrier and now there’s a second breakthrough with their partners at Oxford University (England, UK). From an Aug. 19, 2016 news item on ScienceDaily (Note: A link has been removed),

Scientists at the UK’s Bangor and Oxford universities have achieved a world first: using spider-silk as a superlens to increase the microscope’s potential.

Extending the limit of classical microscope’s resolution has been the ‘El Dorado’ or ‘Holy Grail’ of microscopy for over a century. Physical laws of light make it impossible to view objects smaller than 200 nm — the smallest size of bacteria, using a normal microscope alone. However, superlenses which enable us to see beyond the current magnification have been the goal since the turn of the millennium.

Hot on the heels of a paper (Sci. Adv. 2 e1600901,2016) revealing that a team at Bangor University’s School of Electronic Engineering has used a nanobead-derived superlens to break the perceived resolution barrier, the same team has achieved another world first.

Now the team, led by Dr Zengbo Wang and in colloboration with Prof. Fritz Vollrath’s silk group at Oxford University’s Department of Zoology, has used a naturally occurring material — dragline silk of the golden web spider, as an additional superlens, applied to the surface of the material to be viewed, to provide an additional 2-3 times magnification.

This is the first time that a naturally occurring biological material has been used as a superlens.

An Aug. 19, 2016 Bangor University press release (also on EurekAlert), which originated the news item, provides more information about the new work,

In the paper in Nano Letters (DOI: 10.1021/acs.nanolett.6b02641, Aug 17 2016), the joint team reveals how they used a cylindrical piece of spider silk from the thumb sized Nephila spider as a lens.

Dr Zengbo Wang said:

“We have proved that the resolution barrier of microscope can be broken using a superlens, but production of manufactured superlenses invovles some complex engineering processes which are not widely accessible to other reserchers. This is why we have been interested in looking for naturally occurring superlenses provided by ‘Mother Nature’, which may exist around us, so that everyone can access superlenses.”

Prof Fritz Vollrath adds:

“It is very exciting to find yet another cutting edge and totally novel use for a spider silk, which we have been studying for over two decades in my laboratory.”

These lenses could be used for seeing and viewing previously ‘invisible’ structures, including engineered nano-structures and biological micro-structures as well as, potentially, native germs and viruses.

The natural cylindrical structure at a micron- and submicron-scale make silks ideal candidates, in this case, the individual filaments had diameters of one tenth of a thin human hair.

The spider filament enabled the group to view details on a micro-chip and a blue- ray disk which would be invisible using the unmodified optical microscope.

In much the same was as when you look through a cylindrical glass or bottle, the clearest image only runs along the narrow strip directly opposite your line of vision, or resting on the surface being viewed, the single filament provides a one dimensional viewing image along its length.

Wang explains:

“The cylindrical silk lens has advantages in the larger field-of-view when compared to a microsphere superlens. Importantly for potential commercial applications, a spider silk nanoscope would be robust and economical, which in turn could provide excellent manufacturing platforms for a wide range of applications.”

James Monks, a co-author on the paper comments: “it has been an exciting time to be able to develop this project as part of my honours degree in electronic engineering at Bangor University and I am now very much looking forward to joining Dr Wang’s team as a PhD student in nano-photonics.”

The researchers have provided a close up image with details,

Caption: (a) Nephila edulis spider in its web. (b) Schematic drawing of reflection mode silk biosuperlens imaging. The spider silk was placed directly on top of the sample surface by using a soft tape, which magnify underlying nano objects 2-3 times (c) SEM image of Blu-ray disk with 200/100 nm groove and lines (d) Clear magnified image (2.1x) of Blu-ray disk under spider silk superlens. Credit: Bangor University/ University of Oxford

Caption: (a) Nephila edulis spider in its web. (b) Schematic drawing of reflection mode silk biosuperlens imaging. The spider silk was placed directly on top of the sample surface by using a soft tape, which magnify underlying nano objects 2-3 times (c) SEM image of Blu-ray disk with 200/100 nm groove and lines (d) Clear magnified image (2.1x) of Blu-ray disk under spider silk superlens. Credit: Bangor University/ University of Oxford

Here’s a link to and a citation for the ‘spider silk’ superlens paper,

Spider Silk: Mother Nature’s Bio-Superlens by James N. Monks, Bing Yan, Nicholas Hawkins, Fritz Vollrath, and Zengbo Wang. Nano Lett., Article ASAP DOI: 10.1021/acs.nanolett.6b02641 Publication Date (Web): August 17, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Congratulations to Markus Buehler on his Foresight Institute Feynman Prize for advances in nanotechnology

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A May 24, 2016 Massachusetts Institute of Technology (MIT) news release celebrates Markus Buehler’s latest award,

On May 21 [2016], Department of Civil and Environmental Engineering head and McAfee Professor of Engineering Markus J. Buehler received the 2015 Foresight Institute Feynman Prize in Theoretical Molecular Nanotechnology. Buehler’s award was one of three prizes presented by the Foresight Institute, a leading think tank and public interest organization, at its annual conference in Palo Alto, California. …

…

The Foresight Institute recognized Buehler for his important contributions to making nanotechnology scalable for large-scale materials applications, enabled by bottom-up multiscale computational methods, and linking new manufacturing and characterization methods.

Focusing on mechanical properties — especially deformation and failure — and translation from biological materials and structures to bio-inspired synthetic materials, his work has led to the development and application of new modeling, design, and manufacturing approaches for advanced materials that offer greater resilience and a wide range of controllable properties from the nano- to the macroscale.

Buehler’s signature achievement, according to the Institute, is the application of molecular and chemical principles in the analysis of mechanical systems, with the aim to design devices and materials that provide a defined set of functions.

“It’s an incredible honor to receive such an esteemed award. I owe this to the outstanding students and postdocs whom I had a pleasure to work with over the years, my colleagues, as well my own mentors,” Buehler said. “Richard Feynman was a revolutionary scientist of his generation. It’s a privilege to share his goals of researching molecular technology at very small scale to create new, more efficient, and better lasting materials at much larger scale that will help transform lives and industries.”

The two other award winners are Professor Michelle Y. Simmons of the University of New South Wales [Australia], who won the Feynman Prize for Experimental Molecular Nanotechnology, and Northwestern University graduate student Chuyang Cheng, who won the Distinguished Student Award.

I have featured Buehler’s work here a number of times. The most recent appearance was in  a May 29, 2015 posting about synthesizing spider’s silk.

Spider webs inspire liquid wire

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Courtesy University of Oxford

Courtesy University of Oxford

Usually, when science talk runs to spider webs the focus is on strength but this research from the UK and France is all about resilience. From a May 16, 2016 news item on phys.org,

Why doesn’t a spider’s web sag in the wind or catapult flies back out like a trampoline? The answer, according to new research by an international team of scientists, lies in the physics behind a ‘hybrid’ material produced by spiders for their webs.

Pulling on a sticky thread in a garden spider’s orb web and letting it snap back reveals that the thread never sags but always stays taut—even when stretched to many times its original length. This is because any loose thread is immediately spooled inside the tiny droplets of watery glue that coat and surround the core gossamer fibres of the web’s capture spiral.

This phenomenon is described in the journal PNAS by scientists from the University of Oxford, UK and the Université Pierre et Marie Curie, Paris, France.

The researchers studied the details of this ‘liquid wire’ technique in spiders’ webs and used it to create composite fibres in the laboratory which, just like the spider’s capture silk, extend like a solid and compress like a liquid. These novel insights may lead to new bio-inspired technology.

A May 16, 2016 University of Oxford press release (also on EurekAlert), which originated the news item, provides more detail,

Professor Fritz Vollrath of the Oxford Silk Group in the Department of Zoology at Oxford University said: ‘The thousands of tiny droplets of glue that cover the capture spiral of the spider’s orb web do much more than make the silk sticky and catch the fly. Surprisingly, each drop packs enough punch in its watery skins to reel in loose bits of thread. And this winching behaviour is used to excellent effect to keep the threads tight at all times, as we can all observe and test in the webs in our gardens.’

The novel properties observed and analysed by the scientists rely on a subtle balance between fibre elasticity and droplet surface tension. Importantly, the team was also able to recreate this technique in the laboratory using oil droplets on a plastic filament. And this artificial system behaved just like the spider’s natural winch silk, with spools of filament reeling and unreeling inside the oil droplets as the thread extended and contracted.

Dr Hervé Elettro, the first author and a doctoral researcher at Institut Jean Le Rond D’Alembert, Université Pierre et Marie Curie, Paris, said: ‘Spider silk has been known to be an extraordinary material for around 40 years, but it continues to amaze us. While the web is simply a high-tech trap from the spider’s point of view, its properties have a huge amount to offer the worlds of materials, engineering and medicine.

‘Our bio-inspired hybrid threads could be manufactured from virtually any components. These new insights could lead to a wide range of applications, such as microfabrication of complex structures, reversible micro-motors, or self-tensioned stretchable systems.’

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

In-drop capillary spooling of spider capture thread inspires hybrid fibers with mixed solid–liquid mechanical properties by Hervé Elettro, Sébastien Neukirch, Fritz Vollrath, and Arnaud Antkowiak. PNAS doi: 10.1073/pnas.1602451113

This paper appears to be open access.