Tag Archives: goats

Australian peacock spiders, photonic nanostructures, and making money

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 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)

Goats, spider silk, and silkworms

A few years ago (2008), I attended the Cascadia Nanotech Symposium organized by the now defunct, Nanotech BC (British Columbia, Canada) and heard Dr. Frank Ko speak. He is a Canada Research Chair at the University of British Columbia (UBC) who leads the Advanced Fibrous Materials Laboratory and, in his talk, he mentioned that he had added spider genes to goats with the intention of easing the process of spinning goat’s milk thereby exploiting spider silk’s properties.

I’m never especially comfortable about mixing genes between species that, as far as I know, would never have occasion to mingle their genetic material together. It’s a little too close to ‘The Isle of Dr. Moreau’ (Victor Hugo’s novel which I have never read but have heard about). But there were people who had some similar concerns about electricity, which I take for granted, violating the natural order of things as per Carolyn Marvin’s book, When old technologies were new. Consequently, I’m willing to think about it but not terribly happy to do it.

Getting back to spider silk and Dr. Ko’s work, he and others are very interested in exploiting the strength inherent in spider silk. Here’s a description of that strength from an article by David Zax on Fast Company,

Oftentimes, nature is better at building stuff than we are. Spider silk is an example. The tiny threads spun by our eight-legged friends has a tensile strength comparable to high-grade steel. If humans could harness the spider and turn it into a manufacturing agent, the industrial and commercial potentials could be immense. One problem, though: Spidey hasn’t been cooperating. Spiders just don’t spin the stuff in great quantities, and there is no commercially viable way of mass-producing spider silk.

In looking at Dr. Ko’s webpage I see that adding a spider gene to goats may have been his solution to the problem of producing more spider silk (and perhaps other issues as well),

An internationally recognized expert in 3-D complex fiber architecture for structural toughening of composites Professor Ko’s pioneering work on the development of continuous nanocomposite fibrils by co-electrospinning has provided a new pathway to connect nanomaterials to macrostructural design. With an objective to understand the structural basis for the outstanding combination of strength and toughness in spider silk Professor Ko has played a leading role in the study of nanocomposite fibrils from recombinant spider silk. It was demonstrated that 10X increase in strength and 5X increase in modulus were attainable with the addition of 1-3 weight % of carbon nanotube to the recombinant spider silk. Research has been extended to various filler geometry that include graphite nanoplatelet (GNP); nanoparticles such as nanodiamonds and various functional particles.

Zax’s article highlights a different approach to producing greater quantities of spider silk,

There is, however, already a silkworm industry, which yields most of the silk–less strong than the spider’s–that we’re familiar with. A few scientists got a bright idea: what if you could make the silkworm, which is already equipped for industry, spin spider silk?

Notre Dame, the University of Wyoming, and Kraig Biocraft Laboratories, Inc. joined heads, and recently announced that they had succeeded in genetically engineering silkworms so that they produce artificial spider silks. Several biologists teamed up to splice certain DNA from spiders into the genomes of silkworms. The altered silkworms now spin cocoons that are a mixture of silkworm silk and spider silk. Though the tensile strength of the altered silk still falls well short of that of pure spider silk, it’s a step in the right direction.

I can certainly see benefits to this but I sometimes wonder if humans have enough humility and foresight as we embark on ever more subtle manipulations of life.

ETA October 29, 2010: If you are interested in the goat/spider issue, take a look at Andrew Manard’s October 27, 2010 posting on his 2020 Science blog. He’s running a poll on the question,

… why not take the gene responsible for making spider silk, and splice it into a goat [to produce more spider silk]?

Be sure to take a look at the comments, if you’re interested in the history of the technique, which apparently stretches back to the 1950s!