Category Archives: biomimcry

Darwin’s barnacles become unglued

The world’s strongest glue comes from barnacles and those creatures have something to teach us. From a July 18, 2014 news item on Nanowerk,

Over a 150 years since it was first described by Darwin, scientists are finally uncovering the secrets behind the super strength of barnacle glue.

Still far better than anything we have been able to develop synthetically, barnacle glue – or cement – sticks to any surface, under any conditions.

But exactly how this superglue of superglues works has remained a mystery – until now.

An international team of scientists led by Newcastle University, UK, and funded by the US Office of Naval Research, have shown for the first time that barnacle larvae release an oily droplet to clear the water from surfaces before sticking down using a phosphoprotein adhesive.

A July 18, 2014 Newcastle University (UK) press release, which originated the news item, provides some context and describes the research,

“It’s over 150 years since Darwin first described the cement glands of barnacle larvae and little work has been done since then,” says Dr Aldred, a research associate in the School of Marine Science and Technology at Newcastle University, one of the world’s leading institutions in this field of research.

“We’ve known for a while there are two components to the bioadhesive but until now, it was thought they behaved a bit like some of the synthetic glues – mixing before hardening.  But that still left the question, how does the glue contact the surface in the first place if it is already covered with water?  This is one of the key hurdles to developing glues for underwater applications.

“Advances in imaging techniques, such as 2-photon microscopy, have allowed us to observe the adhesion process and characterise the two components. We now know that these two substances play very different roles – one clearing water from the surface and the other cementing the barnacle down.

“The ocean is a complex mixture of dissolved ions, the pH varies significantly across geographical areas and, obviously, it’s wet.  Yet despite these hostile conditions, barnacle glue is able to withstand the test of time.

“It’s an incredibly clever natural solution to this problem of how to deal with a water barrier on a surface it will change the way we think about developing bio-inspired adhesives that are safe and already optimised to work in conditions similar to those in the human body, as well as marine paints that stop barnacles from sticking.”

Barnacles have two larval stages – the nauplius and the cyprid.  The nauplius, is common to most crustacea and it swims freely once it hatches out of the egg, feeding in the plankton.

The final larval stage, however, is the cyprid, which is unique to barnacles.  It investigates surfaces, selecting one that provides suitable conditions for growth. Once it has decided to attach permanently, the cyprid releases its glue and cements itself to the surface where it will live out the rest of its days.

“The key here is the technology.  With these new tools we are able to study processes in living tissues, as they happen. We can get compositional and molecular information by other methods, but they don’t explain the mechanism.  There’s no substitute for seeing things with your own eyes. ” explains Dr Aldred.

“In the past, the strong lasers used for optically sectioning biological samples have typically killed the samples, but now technology allows us to study life processes exactly as they would happen in nature.”

The press release also notes some possible applications for these research findings (Note: Links have been removed),

Publishing their findings this week in the prestigious academic journal Nature Communications, author Dr Nick Aldred says the findings could pave the way for the development of novel synthetic bioadhesives for use in medical implants and micro-electronics.  The research will also be important in the production of new anti-fouling coatings for ships.

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

Synergistic roles for lipids and proteins in the permanent adhesive of barnacle larvae by Neeraj V. Gohad, Nick Aldred, Christopher M. Hartshorn, Young Jong Lee, Marcus T. Cicerone, Beatriz Orihuela, Anthony S. Clare, Dan Rittschof, & Andrew S. Mount. Nature Communications 5, Article number: 4414 doi:10.1038/ncomms5414 Published 11 July 2014

This paper is behind a paywall although a free preview is available via ReadCube Access.

Catch a falling gecko

While discussions of gecko lizards in the ‘nanotechnology world’ are almost always focused on the creature’s adhesive properties, a recent research article in Physical Review E explores the gecko’s ‘loss of grip’. From a July 9, 2014 news item on Nanowerk (Note: A link has been removed),

Geckos and spiders that seem to be able to sit still forever, and walk around upside down have fascinated researchers worldwide for many years. We will soon be able to buy smart new fasteners that hold the same way as the gecko’s foot. But the fact is, sooner or later the grip is lost, no matter how little force is acting on it. Stefan Lindström and Lars Johansson, researchers at the Division of Mechanics, Linköping University, together with Nils Karlsson, recent engineering graduate, have demonstrated this in an article just published in Physical Review E (“Metastable states and activated dynamics in thin-film adhesion to patterned surfaces”).

A June 24, 2014 Linköping University press release (also on EurekAlert but dated July 9, 2014), which originated the news item, describes how this ‘grip loss’ could have implications for graphene production,

…, it’s a phenomenon that can have considerable benefits, for instance in the production of graphene. Graphene consists only of one layer of atom, and which must be easily detached from the substrate.

In his graduation project at the Division of Mechanics, Nils Karlsson studied both the mechanics of the gecko’s leg as well as the adhesion of its foot to the substrate. The gecko’s foot has five toes, all with transverse lamellae. A scanning electron microscope shows that these lamellae consist of a number of small hair-like setae, each with a little film at the end, which resembles a small spatula. These spatulae, roughly 10 nm thick, are what adheres to the substrate.

”At the nano level, conditions are a bit different. The movement of the molecules is negligible in our macroscopic world, but it’s not in the nano world. Nils Karlsson’s graduation project suggested that heat, and consequently the movement of the molecules, has an effect on the adhesion of these spatulae. We wanted to do further analyses, and calculate what actually happens,” explains Stefan Lindström.

They refined the calculations, so they applied to a thin film in contact with an uneven surface (…). So, the film only contacts the uppermost parts of the uneven surface. The researchers also chose to limit the calculations to the type of weak forces that exist between all atoms and molecules – van der Waals forces.

”It’s true, they are small, but they are always there and we know that they are extremely reliant on distance,” says Lars Johansson.

This means that the force is much stronger where the film is very close to a single high point, than when it is quite close to a number of high points. Then, when the film detaches, it does this point by point. This is because both contact surfaces are moving – vibrating. These are tiny movements, but at some stage the movements are in sync, so the surfaces actually lose contact. Then the van der Waals force is so small that the film releases.

”So in reality, we can detach a thin film from the substrate simply by waiting for the right moment. This doesn’t require a great deal of force. The part of the film that remains on the substrate vibrates constantly, and the harder I pull on this part, the faster the film will detach. But how long it takes for the film to detach also depends on the structure of the substrate and the film’s stiffness,” says Stefan Lindström.

In practice this means that even a small force over a long period will cause the film, or for that matter the gecko’s foot, to lose its grip. Which is fine for the gecko, who can scoot off, but maybe not so good for a fastening system. Still – in the right application, this knowledge can be of great industrial benefit.

This is what a gecko’s foot looks like when viewed through a scanning electron microscope,

The pictures of the gecko’s foot is taken by Oskar Geller, Lund University, with a scanning electron microscope.  Linköping University

The pictures of the gecko’s foot is taken by Oskar Geller, Lund University, with a scanning electron microscope. Linköping University

The image looks like a candidate for entry into a nano art show.

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

Metastable states and activated dynamics in thin-film adhesion to patterned surfaces by Stefan B. Lindström, Lars Johansson, and Nils R. Karlsson. DOI 10.1103/PhysRevE.89.062401 Phys. Rev. E 89, 062401 – Published 6 June 2014

This paper is behind a paywall.

Kudos to anyone who recognized the paraphrasing of the song title, ‘Catch a falling star’ in the head for this posting,

Nanocellulose and an intensity of structural colour

I love the topic of structural colour (or color, depending on your spelling preferences) and have covered it many times and in many ways. One of the best pieces I’ve encountered about structural colour (an article by Christina Luiggi for The Scientist provided an overview of structural colour as it’s found in plants and animals) was featured in my Feb. 7, 2013 posting. If you go to my posting, you’ll find a link to Luiggi’s article which I recommend reading in its entirety if you have the time.

As for this latest nanocellulose story, a June 13, 2014 news item on Nanowerk describes University of Cambridge (UK) research into films and structural colour,

Brightly-coloured, iridescent films, made from the same wood pulp that is used to make paper, could potentially substitute traditional toxic pigments in the textile and security industries. The films use the same principle as can be seen in some of the most vivid colours in nature, resulting in colours which do not fade, even after a century.

Some of the brightest and most colourful materials in nature – such as peacock feathers, butterfly wings and opals – get their colour not from pigments, but from their internal structure alone.

Researchers from the University of Cambridge have recreated a similar structure in the lab, resulting in brightly-coloured films which could be used for textile or security applications.

A June 13, 2014 University of Cambridge news release, which originated the news item, describe the phenomenon of structural colour as it applies to cellulose materials,

In plants such as Pollia condensata, striking iridescent and metallic colours are the result of cellulose fibres arranged in spiral stacks, which reflect light at specific wavelengths. [emphasis mine]

Cellulose is made up of long chains of sugar molecules, and is the most abundant biomass material in nature. It can be found in the cells of every plant and is the main compound that gives cell walls their strength.

The news release goes on to provide a brief description of the research,

The researchers used wood pulp, the same material that is used for producing paper, as their starting material. Through manipulating the structure of the cellulose contained in the wood pulp, the researchers were able to fabricate iridescent colour films without using pigments.

To make the films, the researchers extracted cellulose nanocrystals from the wood pulp. When suspended in water, the rod-like nanocrystals spontaneously assemble into nanostructured layers that selectively reflect light of a specific colour. The colour reflected depends on the dimensions of the layers. By varying humidity conditions during the film fabrication, the researchers were able to change the reflected colour and capture the different phases of the colour formation.

Cellulose nanocrystals (CNC) are also known as nanocrystalline cellulose (NCC).

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

Controlled, Bio-inspired Self-Assembly of Cellulose-Based Chiral Reflectors by Ahu Gumrah Dumanli, Gen Kamita, Jasper Landman, Hanne van der Kooij, Beverley J. Glover, Jeremy J. Baumberg, Ullrich Steiner, and Silvia Vignolini. Optical Materials Article first published online: 30 MAY 2014 DOI: 10.1002/adom.201400112

© 2014 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

While the researchers have supplied an image of the Pollia condensata, I prefer this one, which is also featured in my Feb. 7, 2013 posting,

AGELESS BRILLIANCE: Although the pigment-derived leaf color of this decades-old specimen of the African perennial Pollia condensata has faded, the fruit still maintains its intense metallic-blue iridescence.COURTESY OF P.J. RUDALL [downloaded from http://www.the-scientist.com/?articles.view/articleNo/34200/title/Color-from-Structure/]

AGELESS BRILLIANCE: Although the pigment-derived leaf color of this decades-old specimen of the African perennial Pollia condensata has faded, the fruit still maintains its intense metallic-blue iridescence.COURTESY OF P.J. RUDALL [downloaded from http://www.the-scientist.com/?articles.view/articleNo/34200/title/Color-from-Structure/]

Stunning, non?

Franky Shaw speaks out about the Lexis design on his nanotechnology-enabled men’s swim trunks

In a May 29, 2014 posting I featured a Kickstarter project for nanotechnology-enabled men’s swim trunks/shorts,

It seems like a pretty good idea, swimwear that doesn’t get wet, as noted in the Frank Anthony Kickstarter campaign (the comments about the design are after the technology descriptions),

We were tired of having to change shorts every time you leave the beach, having car seats soaked and not being able to go from the beach to a restaurant.

I then went on to comment about one of the designs (there are several others), the Lexis desiign, which I’m not going to reproduce here (you can see it in the May 29, 2014 posting) but here’s a description,

I’m trying to imagine who’d wear this with an image placed so the model appears to be staring into his (the wearer’s) crotch, mouth held invitingly open.

I next related this example to a culture that regularly demeans women and included an extreme example of then recent mass killings in Isla Vista, California, where the shooter who committed suicide had produced a number of videos and a manifesto claiming that women owed him. A commenter for the May 29, 2014 posting later attempted to suggest that I had correlated shorts and a mass shooting. I guess that’s one way to look at it (I replied at some length to that comment).

In any event Mr. Shaw sent me a couple of emails outlining his position and with his permission I am reproducing them here. The first was dated June 2, 2014,

Hi Maryse,

I read your post with regards to my nanotechnology startup swimwear company based out of Toronto, Canada. It was a very interesting read and most of the things within the first few paragraphs I felt displayed what we’re trying to achieve as a company.

After reading your response with regards to objectifying women and relating our ‘Lexis’ shorts towards the mass murder which took place in Isla Vista, California I thought that an explanation was needed to be given.

The Lexis garment was never supposed to be taken as objectifying women in any way. The model is a very beautiful woman who is simply posing for an artistic photograph. I would be lying if I did infact say I didn’t position her on the garment to appear as if she was looking upwards towards the wearer but it was never intended to be taken as “sexually explicit”.

At Frank Anthony swimwear we believe in beauty, whether you are a male or a female we believe that you should embrace your inner sexuality and not be afraid of those who question it. This design is simply showcasing the beauty of a woman and capturing her admiring expression towards our wearer.

We understand it is a “risky” design but then again we are in the fashion industry. There are allot more sexually thought provoking advertisements shown which display both males and females as sexual objects in fashion, because in the end its fun to break the barriers of society once and awhile. It is not  meant to be taken as objectifying or disrespect, it is simply just pointing towards a direction that our users have to fill in the blanks mentally to conclude.

My thoughts go out to the victims of the attack in Isla Vista, California. Mental illness isn’t a funny subject nor should it be taken lightly. It was an extreme case of an untreated illness and we are sorry for the families of the victims.

Thank you for your article.

Regards,
Franky Shaw
CEO, Frank Anthony

Note: The man who killed those people in Isla Vista had been treated for mental illness for many years and was under treatment at the time of the killings.

I received later on June 2, 2014,

Hi Maryse,
At this time I would appreciate that our conversation remains respectful of both parties and that you kindly release my statement with regards to the Lexis design in a separate article.
I am not doing this for publicity nor do I expect anything in return, but I just really don’t tolerate when people call me out for something I don’t stand for such as sexism.

Regards,
Franky

Not having used the word ‘sexism’ in the May 29, 2014  posting, I’m not sure what he’s referring to but perhaps it’s this,

McDonough’s May 27, 2014 posting about Rodger has a title that allows me to take my commentary on the Lexis design from one of mere bad taste to an indication of something far more disturbing, “Rebecca Solnit on Elliot Rodger: “He fits into a culture of rage,” “a culture that considers women tools and playthings and property.”  Getting back to Lexis, she’s on a pair of swim shorts where she looks as if she’s perpetually ready to perform a sexual act. She is at once a tool, a plaything, and a piece of property.

The design sits there on the Frank Anthony Kickstarter campaign webpage and, at this time (June 13, 2014 1040 hours PDT), the company (Canadian, by the way) has raised over $61,000 ($51,000 more than the original goal) with 11 days still left before the campaign is ended. Many news outlets have featured the Frank Anthony Kickstarter campaign along with images of the designs. For example, Olivia Fleming’s June 9, 2014 article for the Daily Mail online focuses on the technology aspect, mentioning that Shaw is 19-year-old, while showcasing some of the designs but omitting the Lexis,

A high school graduate tired of having his car seats soaked after a day at the beach has created swimming shorts that stay dry – even while in the water.

Frank Shaw, from Toronto, Canada, is funding his Frank Anthony swimwear line through Kickstarter, and after 15 days he has already surpassed his $10,000 goal to raise $45,000.

‘We wanted to create a garment that could transition from a day at the beach, to a workout at the gym and a night on the town all without having to change,’ the 19-year-old told MailOnline.

As I understand it, the Daily Mail (a UK newspaper) is not known for its highbrow taste. In fact, I have not seen a single news outlet reproduce the Lexis design as an example of the product line. My guess is that I’m not the only one who thinks the design crosses a line.

Harvest water from desert air with carbon nanotube cups (competition for NBD Nano?)

It’s been a while since I’ve seen Pulickel Ajayan’s name in a Rice University (Texas) news release and I wonder if this is the beginning of a series. I’ve noticed that researchers often publish a series of papers within a few months and then become quiet for two or more years as they work in their labs to gather more information.

This time the research from Pulickel’s lab has focused on the use of carbon nanotubes to harvest water from desert air. From a June 12, 2014 news item on Azonano,

If you don’t want to die of thirst in the desert, be like the beetle. Or have a nanotube cup handy.

New research by scientists at Rice University demonstrated that forests of carbon nanotubes can be made to harvest water molecules from arid desert air and store them for future use.

The invention they call a “hygroscopic scaffold” is detailed in a new paper in the American Chemical Society journal Applied Materials and Interfaces.

Researchers in the lab of Rice materials scientist Pulickel Ajayan found a way to mimic the Stenocara beetle, which survives in the desert by stretching its wings to capture and drink water molecules from the early morning fog.

Here’s more about the research from a June 11, 2014 Rice University news release (by Mike Williams?), which originated the news item,

They modified carbon nanotube forests grown through a process created at Rice, giving the nanotubes a superhydrophobic (water-repelling) bottom and a hydrophilic (water loving) top. The forest attracts water molecules from the air and, because the sides are naturally hydrophobic, traps them inside.

“It doesn’t require any external energy, and it keeps water inside the forest,” said graduate student and first author Sehmus Ozden. “You can squeeze the forest to take the water out and use the material again.”

The forests grown via water-assisted chemical vapor deposition consist of nanotubes that measure only a few nanometers (billionths of a meter) across and about a centimeter long.

The Rice team led by Ozden deposited a superhydrophobic layer to the top of the forest and then removed the forest from its silicon base, flipped it and added a layer of hydrophilic polymer to the other side.

In tests, water molecules bonded to the hydrophilic top and penetrated the forest through capillary action and gravity. (Air inside the forest is compressed rather then expelled, the researchers assumed.) Once a little water bonds to the forest canopy, the effect multiplies as the molecules are drawn inside, spreading out over the nanotubes through van der Waals forces, hydrogen bonding and dipole interactions. The molecules then draw more water in.

The researchers tested several variants of their cup. With only the top hydrophilic layer, the forests fell apart when exposed to humid air because the untreated bottom lacked the polymer links that held the top together. With a hydrophilic top and bottom, the forest held together but water ran right through.

But with a hydrophobic bottom and hydrophilic top, the forest remained intact even after collecting 80 percent of its weight in water.

The amount of water vapor captured depends on the air’s humidity. An 8 milligram sample (with a 0.25-square-centimeter surface) pulled in 27.4 percent of its weight over 11 hours in dry air, and 80 percent over 13 hours in humid air. Further tests showed the forests significantly slowed evaporation of the trapped water.

If it becomes possible to grow nanotube forests on a large scale, the invention could become an efficient, effective water-collection device because it does not require an external energy source, the researchers said.

Ozden said the production of carbon nanotube arrays at a scale necessary to put the invention to practical use remains a bottleneck. “If it becomes possible to make large-scale nanotube forests, it will be a very easy material to make,” he said.

This is not the first time researchers have used the Stenocara beetle (also known as the Namib desert beetle) as inspiration for a water-harvesting material. In a Nov. 26, 2012 posting I traced the inspiration  back to 2001 while featuring the announcement of a new startup company,

… US startup company, NBD Nano, which aims to bring a self-filling water bottle based on Namib desert beetle to market,

NBD Nano, which consists of four recent university graduates and was formed in May [2012], looked at the Namib Desert beetle that lives in a region that gets about half an inch of rainfall per year.

Using a similar approach, the firm wants to cover the surface of a bottle with hydrophilic (water-attracting) and hydrophobic (water-repellent) materials.

The work is still in its early stages, but it is the latest example of researchers looking at nature to find inspiration for sustainable technology.

“It was important to apply [biomimicry] to our design and we have developed a proof of concept and [are] currently creating our first fully-functional prototype,” Miguel Galvez, a co-founder, told the BBC.

“We think our initial prototype will collect anywhere from half a litre of water to three litres per hour, depending on local environments.”

You can find out more about NBD Nano here although they don’t give many details about the material they’ve developed. Given that MIT (Massachusetts Institute of Technology) researchers published a  paper about a polymer-based material laced with silicon nanoparticles inspired by the Namib beetle in 2006 and that NBD Nano is based Massachusetts, I believe NBD Nano is attempting to commercialize the material or some variant developed at MIT.

Getting back to Rice University and carbon nanotubes, this is a different material attempting to achieve the same goal, harvesting water from desert air. Here’s a link to and a citation for the latest paper inspired by the Stenocara beetle (Namib beetle),

Anisotropically Functionalized Carbon Nanotube Array Based Hygroscopic Scaffolds by Sehmus Ozden, Liehui Ge , Tharangattu N. Narayanan , Amelia H. C. Hart , Hyunseung Yang , Srividya Sridhar , Robert Vajtai , and Pulickel M Ajayan. ACS Appl. Mater. Interfaces, DOI: 10.1021/am5022717 Publication Date (Web): June 4, 2014

Copyright © 2014 American Chemical Society

This paper is behind a paywall.

One final note, the research at MIT was funded by DARPA (US Defense Advanced Research Projects Agency). According to the news release the Rice University research held interest for similar agencies,

The U.S. Department of Defense and the U.S. Air Force Office of Scientific Research Multidisciplinary University Research Initiative supported the research.

Climb like a gecko (in DARPA’s [US Defense Advanced Research Projects Agency] Z-Man program)

I’m not entirely certain why DARPA (US Defense Advanced Research Projects Agency) has now issued a news release (h/t June 5, 2014 news item on Nanowerk) about this achievement (a human climbing like a Gecko) which seems to have first occurred in 2012 but perhaps they want to emphasize that this particular demonstration occurred on a glass wall. In any event, I’m happy to get more news about DARPA’s Z-Man program. From the June 5, 2014 DARPA news release,

DARPA’s Z-Man program has demonstrated the first known human climbing of a glass wall using climbing devices inspired by geckos. The historic ascent involved a 218-pound climber ascending and descending 25 feet of glass, while also carrying an additional 50-pound load in one trial, with no climbing equipment other than a pair of hand-held, gecko-inspired paddles. [emphasis mine] The novel polymer microstructure technology used in those paddles was developed for DARPA by Draper Laboratory of Cambridge, Mass. [Massachusetts]

Historically, gaining the high ground has always been an operational advantage for warfighters, but the climbing instruments on which they’re frequently forced to rely—tools such as ropes and ladders—have not advanced significantly for millennia. Not only can the use of such tools be overt and labor intensive, they also only allow for sequential climbing whereby the first climber often takes on the highest risk.

DARPA created the Z-Man program to overcome these limitations and deliver maximum safety and flexibility for maneuver and rapid response to warfighters operating in tight urban environments. The goal of the program is to develop biologically inspired climbing aids to enable warfighters carrying a full combat load to scale vertical walls constructed from typical building materials.

“The gecko is one of the champion climbers in the Animal Kingdom, so it was natural for DARPA to look to it for inspiration in overcoming some of the maneuver challenges that U.S. forces face in urban environments,” said Dr. Matt Goodman, the DARPA program manager for Z-Man. “Like many of the capabilities that the Department of Defense pursues, we saw with vertical climbing that nature had long since evolved the means to efficiently achieve it. The challenge to our performer team was to understand the biology and physics in play when geckos climb and then reverse-engineer those dynamics into an artificial system for use by humans.”

Geckos can climb on a wide variety of surfaces, including smooth surfaces like glass, with adhesive pressures of 15-30 pounds per square inch for each limb, meaning that a gecko can hang its entire body by one toe. The anatomy of a gecko toe consists of a microscopic hierarchical structure composed of stalk-like setae (100 microns in length, 2 microns in radius). From individual setae, a bundle of hundreds of terminal tips called spatulae (approximately 200 nanometers in diameter at their widest) branch out and contact the climbing surface.

A gecko is able to climb on glass by using physical bond interactions—specifically van der Waals intermolecular forces—between the spatulae and a surface to adhere reversibly, resulting in easy attachment and removal of the gecko’s toes from the surface. The van der Waals mechanism implied that it is the size and shape of the spatulae tips that affect adhesive performance, not specific surface chemistry. This suggested that there were design principles and physical models derived from nature that might enable scientists to fabricate an adhesive inspired by gecko toes.

Humans, of course, have much more weight to carry than a gecko. One of the initial challenges in developing a device to support human climbing was the issue of scaling: a typical Tokay gecko weighs 200 grams, while an average human male weighs 75 kilograms. To enable dynamic climbing like a gecko at this larger scale required that the engineers create climbing paddles capable of balancing sufficient adhesive forces in both the shear (parallel to the vertical surface) and normal (perpendicular to the vertical surface) directions. That feature is necessary for a climber to remain adhered on a surface without falling off while in the act of attaching and detaching the paddles with each movement.

The Draper Laboratory team was also challenged to create novel micro- and nanofabrication technologies to produce the high-aspect-ratio microstructures found in the gecko toe. In the process of achieving that capability, the Z-Man performers transformed the fundamental design and development of reversible adhesives for potential biomedical, industrial, and consumer applications.

The first human climbing demonstration occurred in February 2012 and tests of the technology are ongoing. [emphasis mine]

I’m guessing that glass is difficult to photograph because the image which accompanies the DARPA news release doesn’t highlight the achievement in quite the way one would expect,

During testing, an operator climbed 25 feet vertically on a glass surface using no climbing equipment other than a pair of hand-held, gecko-inspired paddles. The climber wore, but did not require, the use of a safety belay. Image: DARPA

During testing, an operator climbed 25 feet vertically on a glass surface using no climbing equipment other than a pair of hand-held, gecko-inspired paddles. The climber wore, but did not require, the use of a safety belay. Image: DARPA

I last wrote about Z-man in an April 3, 2012 posting highlighting some DARPA-funded work being done at the University of Massachusetts at Amherst while also mentioning work being done in other labs not associated (to my knowledge) with DARPA.

I was not successful in my attempts to find a video highlighting this ‘glass wall’ achievement but I did find this episode of Science Friction, where the host, Rusty Ward, does a very nice job of describing the technology (van der Waals forces, the nanostructures allowing spiders and geckos to climb all sorts of surfaces, etc.) along with some pop culture references (Spider-Man),

This runs for approximately 5 mins. 30 secs., a bit longer than usual for a video embedded here.

One last note, for anyone curious the laboratory referenced in the news release, you can find more here at the (Charles Stark) Draper Laboratory Wikipedia entry.

Protein nanomachines at the University of Washington

Scouring pad or protein nanomachine?

Caption: This is a computational model of a successfully designed two-component protein nanocage with tetrahedral symmetry. Credit: Dr. Vikram Mulligan

Caption: This is a computational model of a successfully designed two-component protein nanocage with tetrahedral symmetry.
Credit: Dr. Vikram Mulligan

This illustration of a protein nanocage reminded me of a type of scouring pad, which come to think of it, I haven’t seen in any stores for some years. Getting back on topic, this nanocage is a first step to building nanomachines according to a June 5, 2014 news item on Nanowerk,

A route for constructing protein nanomachines engineered for specific applications may be closer to reality.

Biological systems produce an incredible array of self-assembling, functional protein tools. Some examples of these nanoscale protein materials are scaffolds to anchor cellular activities, molecular motors to drive physiological events, and capsules for delivering viruses into host cells.

Scientists inspired by these sophisticated molecular machines want to build their own, with forms and functions customized to tackle modern-day challenges. The ability to design new protein nanostructures could have useful implications in targeted delivery of drugs, in vaccine development and in plasmonics, which is manipulating electromagnetic signals to guide light diffraction for information technologies, energy production or other uses.

A recently developed computational method may be an important step toward that goal. The project was led by the University of Washington’s [Washington state] Neil King, translational investigator; Jacob Bale, graduate student in Molecular and Cellular Biology; and William Sheffler in David Baker’s laboratory at the University of Washington Institute for Protein Design, in collaboration with colleagues at UCLA [University of California at Los Angeles] and Janelia Farm.

The work is based in the Rosetta macromolecular modeling package developed by Baker and his colleagues. The program was originally created to predict natural protein structures from amino acid sequences. Researchers in the Baker lab and around the world are increasingly using Rosetta to design new protein structures and sequences aimed at solving real-world problems.

A June 4 (?), 2014 University of Washington news release by Leila Gray (also on EurekAlert), which originated the news item, provides more detail about the models and what the scientists hope to accomplish,

“Proteins are amazing structures that can do remarkable things,” King said, “they can respond to changes in their environment. Exposure to a particular metabolite or a rise in temperature, for example, can trigger an alteration in a particular protein’s shape and function.” People often call proteins the building blocks of life.

“But unlike, say, a PVC pipe,” King said, “they are not simply construction material.” They are also construction (and demolition) workers — speeding up chemical reactions, breaking down food, carrying messages, interacting with each other, and performing countless other duties vital to life.

With the new software the scientists were able to create five novel, 24-subunit cage-like protein nanomaterials. Importantly, the actual structures, the researchers observed, were in very close agreement with their computer modeling.

Their method depends on encoding pairs of protein amino acid sequences with the information needed to direct molecular assembly through protein-protein interfaces. The interfaces not only provide the energetic forces that drive the assembly process, they also precisely orient the pairs of protein building blocks with the geometry required to yield the desired cage-like symmetric architectures.

Creating this cage-shaped protein, the scientists said, may be a first step towards building nano-scale containers. [emphasis mine] King said he looks forward to a time when cancer-drug molecules will be packaged inside of designed nanocages and delivered directly to tumor cells, sparing healthy cells.

“The problem today with cancer chemotherapy is that it hits every cell and makes the patient feel sick,” King said. Packaging the drugs inside customized nanovehicles with parking options restricted to cancer sites might circumvent the side effects.

The scientists note that combining just two types of symmetry elements, as in this study, can in theory give rise to a range of symmetrical shapes, such as cubic point groups, helices, layers, and crystals.

King explained that the immune system responds to repetitive, symmetric patterns, such as those on the surface of a virus or disease bacteria. Building nano-decoys may be a way train the immune system to attack certain types of pathogens.

“This concept may become the foundation for vaccines based on engineered nanomaterials,” King said. Further down the road, he and Bale anticipate that these design methods might also be useful for developing new clean energy technologies.

The scientists added in their report, “The precise control over interface geometry offered by our method enables the design of two-component protein nanomaterials with diverse nanoscale features, such as surfaces, pores, and internal volumes, with high accuracy.”

They went on to say that the combinations possible with two-component materials greatly expand the number and variety of potential nanomaterials that could be designed.

It may be possible to produce nanomaterials in a variety of sizes, shapes and arrangements, and also move on to construct increasingly more complex materials from more than two components.

The researchers emphasized that the long-term goal of such structures is not to be static. The hope is that they will mimic or go beyond the dynamic performance of naturally occurring protein assemblies, and that eventually novel molecular protein machines could be manufactured with programmable functions. [emphasis mine]

The researchers pointed out that although designing proteins and protein-based nanomaterials is very challenging due to the relative complexity of protein structures and interactions, there are now more than a handful of laboratories around the world making major strides in this field. Each of the leading contributors have key strengths, they said. The strengths of the UW team is in the accuracy of the match of the designed proteins to the computational models and the predictability of the results.

It seems like it’s going to be several years before we have protein nanomachines. Here’s a link to and a citation for the research paper,

Accurate design of co-assembling multi-component protein nanomaterials by Neil P. King, Jacob B. Bale, William Sheffler, Dan E. McNamara, Shane Gonen, Tamir Gonen, Todd O. Yeates, & David Baker. Nature 510, 103–108 (05 June 2014) doi:10.1038/nature13404 Published online 25 May 2014

This paper is behind a paywall but there is a free preview via ReadCube Access.

For anyone curious about the Rosetta macromolecular modeling package used in this work, you can find out more here at the Rosetta Commons website.  As for Janelia Farm, it is a research center in Virginia and is part of the Howard Hughes Medical Institute.

Dental implants with a surface that affects genetic cellular expression

Intra-Lock International is trumpeting in triumph in the wake  of a study noting their OSSEAN-surfaced dental implants promote better bone-healing than an alternative used for comparison. From the June 10, 2014 news item on Azonano,

As reported in the internationally renowned scientific journal, Bone [in press for Aug. 2014], a research team from New York University [NYU] has confirmed what scientific developers at Intra-Lock® International, Inc. have known for several years: the fractal, nano-rough OSSEAN® surface developed for their dental implants actually changes the cellular genetic expression – or the fate of stem cells – at the nano-level, which in turn induces faster healing of implants.

A June 9, 2014 Intra-Lock news release, which originated the new item, describes what usually occurs when an implant is first situated in the tissue (cellular confusion) and how the OSSEAN surface affects the ‘confusion’,

Typically, when an implant is surgically placed, there is a period of cellular “confusion” and chaos around the implant, and usually a little bone resorbs before being formed again. The implant is then at risk from the moment it is inserted through the time when the bone is healed around it – a time period Giorno [Thierry M. Giorno, DDS, director of research and development, and CEO of Intra-Lock®, International] refers to as “the window of negative opportunity.”

However, the NYU researchers found that bone cells immediately start clustering around the OSSEAN implants and begin accelerated healing, with little confusion whatsoever.

This occurs primarily due to the biomimetic structure of the OSSEAN surface, designed and classified as nanorough and fractalii. Mimicking nature at the nano-level, the OSSEAN surface repeats a similar structural pattern to that of natural bone over and over, essentially “tricking” the body into accepting the implant as a natural substance and igniting the healing process far sooner than would occur with an artificial substance, which is smooth at the nano-level and without natural-seeming pattern repetition.

Typically, with an implant of any sort, whether it’s a dental implant in your jaw or a titanium rod in your leg, several weeks will pass before the bone begins to grow around it. During this time lapse, known as the “catabolic phase,” there can be great risk and instability with the implant.

Naturally, compressing the healing time and accelerating the degree of osseointegration – the merging of implant and bone – are highly desirable outcomes, and implants with an OSSEAN can provide a faster healing process, which thereby reduces patient discomfort and provides a higher potential for successful long-term results with the implant.

“If you’ve ever had dental implants, you can appreciate the outcomes the OSSEAN surface provides,” said Giorno. “The healing process has changed forever, and future patients with an OSSEAN surface implant can look forward to reduced complications, overall.”

Looking further into the future, Giorno said, “I believe the effects of OSSEAN can potentially revolutionize the implant industry beyond dentistry and into all types of orthopedics where patients must wait for their bodies to accept a foreign substance. With OSSEAN, the wait is over.”

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

Nanometer-scale features on micrometer-scale surface texturing: A bone histological, gene expression, and nanomechanical study by Paulo G. Coelho, Tadahiro Takayama, Daniel Yoo, Ryo Jimboemail, Sanjay Karunagaran, Nick Tovar, Malvin N. Janal, and Seiichi Yamano. Bone, Issue 65, Aug. 2014. Bone (2014) DOI: http://dx.doi.org/10.1016/j.bone.2014.05.004 Published Online: May 07, 2014

This article is behind a paywall. You can find out more about Intra-Lock and OSSEAN here.

Music on the web, a spider’s web, that is

I was expecting to see Markus Buehler and MIT (Massachusetts Institute of Technology) mentioned in this latest work on spiderwebs and music. Surprise! This latest research is from three universities in the UK as per a June 3, 2014 news item on ScienceDaily,

Spider silk transmits vibrations across a wide range of frequencies so that, when plucked like a guitar string, its sound carries information about prey, mates, and even the structural integrity of a web.

The discovery was made by researchers from the Universities of Oxford, Strathclyde, and Sheffield who fired bullets and lasers at spider silk to study how it vibrates. They found that, uniquely, when compared to other materials, spider silk can be tuned to a wide range of harmonics. The findings, to be reported in the journal Advanced Materials, not only reveal more about spiders but could also inspire a wide range of new technologies, such as tiny light-weight sensors.

A June 3, 2014 University of Oxford news release (also on EurekAlert), which originated the news item, explains the research and describes how it was conducted (firing bullets?),

‘Most spiders have poor eyesight and rely almost exclusively on the vibration of the silk in their web for sensory information,’ said Beth Mortimer of the Oxford Silk Group at Oxford University, who led the research. ‘The sound of silk can tell them what type of meal is entangled in their net and about the intentions and quality of a prospective mate. By plucking the silk like a guitar string and listening to the ‘echoes’ the spider can also assess the condition of its web.’

‘Most spiders have poor eyesight and rely almost exclusively on the vibration of the silk in their web for sensory information,’ said Beth Mortimer of the Oxford Silk Group at Oxford University, who led the research. ‘The sound of silk can tell them what type of meal is entangled in their net and about the intentions and quality of a prospective mate. By plucking the silk like a guitar string and listening to the ‘echoes’ the spider can also assess the condition of its web.’

This quality is used by the spider in its web by ‘tuning’ the silk: controlling and adjusting both the inherent properties of the silk, and the tensions and interconnectivities of the silk threads that make up the web. To study the sonic properties of the spider’s gossamer threads the researchers used ultra-high-speed cameras to film the threads as they responded to the impact of bullets. [emphasis mine] In addition, lasers were used to make detailed measurements of even the smallest vibration.

‘The fact that spiders can receive these nanometre vibrations with organs on each of their legs, called slit sensillae, really exemplifies the impact of our research about silk properties found in our study,’ said Dr Shira Gordon of the University of Strathclyde, an author involved in this research.

‘These findings further demonstrate the outstanding properties of many spider silks that are able to combine exceptional toughness with the ability to transfer delicate information,’ said Professor Fritz Vollrath of the Oxford Silk Group at Oxford University, an author of the paper. ‘These are traits that would be very useful in light-weight engineering and might lead to novel, built-in ‘intelligent’ sensors and actuators.’

Dr Chris Holland of the University of Sheffield, an author of the paper, said: ‘Spider silks are well known for their impressive mechanical properties, but the vibrational properties have been relatively overlooked and now we find that they are also an awesome communication tool. Yet again spiders continue to impress us in more ways than we can imagine.’

Beth Mortimer said: ‘It may even be that spiders set out to make a web that ‘sounds right’ as its sonic properties are intimately related to factors such as strength and flexibility.’

The research paper has not yet been published in Advanced Materials (I checked this morning, June 4, 2014).

However, there is this video from the researchers,

As for Markus Buehler’s work at MIT, you can find out more in my Nov. 28, 2012 posting, Producing stronger silk musically.

Forever dry, nanotechnology-enabled swim shorts for men and a design that intentionally or not is demeaning

It seems like a pretty good idea, swimwear that doesn’t get wet, as noted in the Frank Anthony Kickstarter campaign (the comments about the design are after the technology descriptions),

We were tired of having to change shorts every time you leave the beach, having car seats soaked and not being able to go from the beach to a restaurant. We decided to look at different topical applications for use but shortly found out they changed the texture of the fabric and had no way of being used on garments. We decided to scrap the idea and look for the perfect alternative. We found the leading textile manufacturer who specializes in high performance nanotechnology fabrics operating out of Switzerland, and focused extensively on creating the most visually appealing and scientifically advanced pair of swim shorts in the world.

The technical description leaves a little to be desired, from the campaign page,

The fabric we use has a hydrophobic nanostructure inside the actual fabric itself, making it breathable and completely safe for use. We are currently the only swimwear company on the market using this hydrophobic nanotechnology fabric. This fabric has proven to drastically reduce dry-times by up to 95% in contrast to regular 100% polyester swim shorts.

The shorts are manufactured in Italy with Swiss Fabric.

What is Swiss fabric? There are synthetics, cotton, linen, etc.  There’s even a ‘dotted Swiss’ but that’s a sheer cotton. Perhaps the writer meant Swiss-made fabric. As for the “hydrophobic nanostructure [i.e., water-repelling like a lotus leaf],” does this mean some Swiss manufacturer has developed a new technique? This is possible, Teijin, a Japanese multinational, claimed they’d produced a fabric having nanoscale properties that were carried over to the macroscale in a July 19, 2010 about a fabric based on the nanostructures found on a Morpho butterfly’s wing.

Getting back to the swimshorts, they can be washed (how do you clean something with water when it repels water?),

Yes, they should be washed with like colours and there is no need to iron or dry clean them. The Hydrophobic Nanotechnology is not affected by any form of washing and will not deteriorate.

I found a possible answer to the ‘washing question from the comments section of this Kickstarter campaign,

… our shorts are made up of billions of nanoscale whisker like barriers preventing any water based liquid from absorption. When the shorts are fully submerged underwater you will see a silver appearance on the exterior. This is [sic] the air bubbles the nanotechnology is creating around the garment protecting it from the water surrounding the short. When you come out of the water, the most our users will experience are droplets on the exterior of the short, there will be no actual water absorbed within the fabric itself due to it’s nano structure. We’ve found this makes our shorts dry on average 95% faster then any other swim short on the market using polyester or nylon. I hope this helps clear things up. Thanks for your support!

So, the shorts do get wet but dry very, very quickly.

There is a May 23, 2014 article by Amanda Kooser for CNET.com which features an interview with Franky Shaw, CEO (chief executive officer) of the start-up company producing the swim shorts,

“We have created a unique polyester blend that incorporates hydrophobic nanotechnology within the fabric, making it completely free of any hazardous effects topical nanotechnology coatings may possess. With the nanotechnology inside the fabric preventing all water-based substances from absorption, you are able to freely wash our shorts just like any other clothing item, without the fear of reducing its hydrophobic capabilities,” says Shaw.

Interestingly, while this news is making a bit of splash and is being featured on a number of site along with pictures, no one is including this Lexis design,

[downloaded from http://www.frankanthonyshorts.com/collections/all]

[downloaded from http://www.frankanthonyshorts.com/collections/all]

I’m trying to imagine who’d wear this with an image placed so the model appears to be staring into his (the wearer’s) crotch, mouth held invitingly open.

Given the May 23, 2014 killings in Isla Vista, California (you can find an accounting of this extended killing spree in a May 25, 2014 article in the National Post), the Lexis design provides an unexpected (I don’t usually see this sort of thing in nanotechnology-enabled product marketing) example of the pervasive nature of the disrespect offered to women.

From a May 25, 2014 essay by Katie McDonough on Salon.com, Note: Links have been removed,

We don’t yet know much about the six innocent women and men who were killed in Isla Vista, California late Friday night [May 23, 2014], but we have come to know a few things about the man who is alleged to have murdered them. Hours before he is believed to have fatally stabbed and shot six people and wounded 13 others in that coastal college town, Elliot Rodger filmed a video of himself — palm trees behind him, the glow of an orange sun highlighting his young face — and vowed to get “revenge against humanity.”

There’s a lot more in the video, and the 140-page “manifesto” he left in his apartment. Rodger felt victimized by women, whom he appeared to desire and loathe simultaneously. He expressed anger and resentment toward other men, often because of their relationships with women. …

It would be irresponsible to lay this violence at the feet of the men’s rights activists with whom Rodger seemed to find support for his rage. Rodger is alleged to have murdered six women and men. No amount of Internet vitriol — no unfulfilled threats of violence — can equal that. But it also denies reality to pretend that Rodger’s sense of masculine entitlement and views about women didn’t matter or somehow existed in a vacuum. The horror of Rodger’s alleged crimes is unique, but the distorted way he understood himself as a man and the violence with which he discussed women — the bleak and dehumanizing way he judged them — is not. Just as we examine our culture of guns once again in the wake of yet another mass shooting, we must also examine our culture of misogyny and toxic masculinity, which devalues both women’s and men’s lives and worth, and inflicts real and daily harm. We must examine the dangerous normative values that treat women as less than human, and that make them — according to Elliot Rodger — deserving of death. [emphasis mine]

McDonough’s May 27, 2014 posting about Rodger has a title that allows me to take my commentary on the Lexis design from one of mere bad taste to an indication of something far more disturbing, “Rebecca Solnit on Elliot Rodger: “He fits into a culture of rage,” “a culture that considers women tools and playthings and property.”  Getting back to Lexis, she’s on a pair of swim shorts where she looks as if she’s perpetually ready to perform a sexual act. She is at once a tool, a plaything, and a piece of property.

This is a Canadian (based in Toronto, Ontario according to the Kickstarter page) company and their Frank Anthony swim short Kickstarter campaign is doing well having achieved over $20,000 in pledges towards at $10,000 goal and with 26 days left.

Final questions, did the model know how her image was going to be used? Is the company getting orders for the Lexis design? If so, how many? And, why in God’s name hasn’t the company removed that design from its marketing collateral and from production?

I think that bit in McDonough’s essay where she notes that both men’s and women’s lives are devalued by misogyny and objectification is in that category of observations that is least understood by the people who most need it. I offer my sympathies to all those affected by the killings and injuries in Isla Vista.