Single layer graphene as a solid lubricant

Graphite (from which graphene springs) has been used as a solid lubricant for many years but it has limitations which researchers at the US Dept. of Energy’s Argonne National Laboratory are attempting to overcome by possibly replacing it with graphene. An Oct. 14, 2014 news item on phys.org describes the research (Note: A link has been removed),

Nanoscientist Anirudha Sumant and his colleagues at Argonne’s Center for Nanoscale Materials and Argonne’s Energy Systems division applied a one-atom-thick layer of graphene, a two-dimensional form of carbon, in between a steel ball and a steel disk. They found that just the single layer of graphene lasted for more than 6,500 “wear cycles,” a dramatic improvement over conventional lubricants like graphite or molybdenum disulfide.

An Oct. 13, 2014 Argonne National Laboratory news release by Jared Sagoff, which originated the news item, provides more information about this research (Note: A link has been removed),

“For comparison,” Sumant said, “conventional lubricants would need about 1,000 layers to last for 1,000 wear cycles. That’s a huge advantage in terms of cost savings with much better performance.”

Graphite has been used as an industrial lubricant for more than 40 years, but not without certain drawbacks, Sumant explained.  “Graphite is limited by the fact that it really works only in humid environments. If you have a dry setting, it’s not going to be nearly as effective,” he said.

This limitation arises from the fact that graphite – unlike graphene – has a three-dimensional structure.  The water molecules in the moist air create slipperiness by weaving themselves in between graphite’s carbon sheets. When there are not enough water molecules in the air, the material loses its slickness.

Molybdenum disulfide, another common lubricant, has the reverse problem, Sumant said. It works in dry environments but not well in wet ones. “Essentially the challenge is to find a single all-purpose lubricant that works well for mechanical systems, no matter where they are,” he said.

Graphene’s two-dimensional structure gives it a significant advantage. “The material is able to bond directly to the surface of the stainless steel ball, making it so perfectly even that even hydrogen atoms are not able to penetrate it,” said Argonne materials scientist Ali Erdemir, a collaborator on the study who tested graphene-coated steel surfaces in his lab.

In a previous study in Materials Today, Sumant and his colleagues showed that a few layers of graphene works equally well in humid and dry environments as a solid lubricant, solving the 40-year-old puzzle of finding a flawless solid lubricant. However, the team wanted to go further and test just a single graphene layer.

While doing so in an environment containing molecules of pure hydrogen, they observed a dramatic improvement in graphene’s operational lifetime. When the graphene monolayer eventually starts to wear away, hydrogen atoms leap in to repair the lattice, like stitching a quilt back together. “Hydrogen can only get into the fabric where there is already an opening,” said Subramanian Sankaranarayanan, an Argonne computational scientist and co-author in this study. This means the graphene layer stays intact longer.

Researchers had previously done experiments to understand the mechanical strength of a single sheet of graphene, but the Argonne study is the first to explain the extraordinary wear resistance of one-atom-thick graphene.

Here’s a link to and a citation for the August 2014 study,

Extraordinary Macroscale Wear Resistance of One Atom Thick Graphene Layer by Diana Berman, Sanket A. Deshmukh, Subramanian K. R. S. Sankaranarayanan, Ali Erdemir, and Anirudha V. Sumant. Advanced Funtional Materials DOI: 10.1002/adfm.201401755 Article first published online: 26 AUG 2014

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This article is behind a paywall.

Silver nanoparticles: liquid on the outside, crystal on the inside

Research from the Massachusetts Institute of Technology (MIT) has revealed a new property of metal nanoparticles, in this case, silver. From an Oct. 12, 2014 news item on ScienceDaily,

A surprising phenomenon has been found in metal nanoparticles: They appear, from the outside, to be liquid droplets, wobbling and readily changing shape, while their interiors retain a perfectly stable crystal configuration.

The research team behind the finding, led by MIT professor Ju Li, says the work could have important implications for the design of components in nanotechnology, such as metal contacts for molecular electronic circuits.

The results, published in the journal Nature Materials, come from a combination of laboratory analysis and computer modeling, by an international team that included researchers in China, Japan, and Pittsburgh, as well as at MIT.

An Oct. 12, 2014 MIT news release (also on EurekAlert), which originated the news item, offers both more information about the research and a surprising comparison of nanometers to the width of a human hair,

The experiments were conducted at room temperature, with particles of pure silver less than 10 nanometers across — less than one-thousandth of the width of a human hair. [emphasis mine] But the results should apply to many different metals, says Li, senior author of the paper and the BEA Professor of Nuclear Science and Engineering.

Silver has a relatively high melting point — 962 degrees Celsius, or 1763 degrees Fahrenheit — so observation of any liquidlike behavior in its nanoparticles was “quite unexpected,” Li says. Hints of the new phenomenon had been seen in earlier work with tin, which has a much lower melting point, he says.

The use of nanoparticles in applications ranging from electronics to pharmaceuticals is a lively area of research; generally, Li says, these researchers “want to form shapes, and they want these shapes to be stable, in many cases over a period of years.” So the discovery of these deformations reveals a potentially serious barrier to many such applications: For example, if gold or silver nanoligaments are used in electronic circuits, these deformations could quickly cause electrical connections to fail.

It was a bit surprising to see the reference to 10 nanometers as being less than 1/1,000th (one/one thousandth) of the width of a human hair in a news release from MIT. Generally, a nanometer has been described as being anywhere from less than 1/50,000th to 1/120,000th of the width of a human hair with less than 1/100,000th being one of the most common descriptions. While it’s true that 10 nanometers is less than 1/1,000th of the width of a human hair, it seems a bit misleading when it could be described, in keeping with the more common description, as less than 1/10,000th.

Getting back to the research, the news release offers more details as to how it was conducted,

The researchers’ detailed imaging with a transmission electron microscope and atomistic modeling revealed that while the exterior of the metal nanoparticles appears to move like a liquid, only the outermost layers — one or two atoms thick — actually move at any given time. As these outer layers of atoms move across the surface and redeposit elsewhere, they give the impression of much greater movement — but inside each particle, the atoms stay perfectly lined up, like bricks in a wall.

“The interior is crystalline, so the only mobile atoms are the first one or two monolayers,” Li says. “Everywhere except the first two layers is crystalline.”

By contrast, if the droplets were to melt to a liquid state, the orderliness of the crystal structure would be eliminated entirely — like a wall tumbling into a heap of bricks.

Technically, the particles’ deformation is pseudoelastic, meaning that the material returns to its original shape after the stresses are removed — like a squeezed rubber ball — as opposed to plasticity, as in a deformable lump of clay that retains a new shape.

The phenomenon of plasticity by interfacial diffusion was first proposed by Robert L. Coble, a professor of ceramic engineering at MIT, and is known as “Coble creep.” “What we saw is aptly called Coble pseudoelasticity,” Li says.

Now that the phenomenon has been understood, researchers working on nanocircuits or other nanodevices can quite easily compensate for it, Li says. If the nanoparticles are protected by even a vanishingly thin layer of oxide, the liquidlike behavior is almost completely eliminated, making stable circuits possible.

There are some benefits to this insight (from the news release),

On the other hand, for some applications this phenomenon might be useful: For example, in circuits where electrical contacts need to withstand rotational reconfiguration, particles designed to maximize this effect might prove useful, using noble metals or a reducing atmosphere, where the formation of an oxide layer is destabilized, Li says.

The new finding flies in the face of expectations — in part, because of a well-understood relationship, in most materials, in which mechanical strength increases as size is reduced.

“In general, the smaller the size, the higher the strength,” Li says, but “at very small sizes, a material component can get very much weaker. The transition from ‘smaller is stronger’ to ‘smaller is much weaker’ can be very sharp.”

That crossover, he says, takes place at about 10 nanometers at room temperature — a size that microchip manufacturers are approaching as circuits shrink. When this threshold is reached, Li says, it causes “a very precipitous drop” in a nanocomponent’s strength.

The findings could also help explain a number of anomalous results seen in other research on small particles, Li says.

For more details about the various attempts to create smaller computer chips, you can read my July 11, 2014 posting about IBM and its proposed 7 nanometer chip where you will also find links to announcements and posts about Intel’s smaller chips and HP Labs’ attempt to recreate computers.

As for the research into liquid-like metallic (silver) nanoparticles, here’s a link to and a citation for the paper,

Liquid-like pseudoelasticity of sub-10-nm crystalline ​silver particle by Jun Sun, Longbing He, Yu-Chieh Lo, Tao Xu, Hengchang Bi, Litao Sun, Ze Zhang, Scott X. Mao, & Ju Li. Nature Materials (2014) doi:10.1038/nmat4105 Published online 12 October 2014

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

SLIPS (Slippery Liquid-Infused Porous Surfaces) technology repels blood and bacteria from medical devices

Researchers at Harvard University’s Wyss Institute for Biologically Inspired Engineering have developed a coating for medical devices that helps to address some of these devices’ most  troublesome aspects. From an Oct. 12, 2014 news item on ScienceDaily,

From joint replacements to cardiac implants and dialysis machines, medical devices enhance or save lives on a daily basis. However, any device implanted in the body or in contact with flowing blood faces two critical challenges that can threaten the life of the patient the device is meant to help: blood clotting and bacterial infection.

A team of Harvard scientists and engineers may have a solution. They developed a new surface coating for medical devices using materials already approved by the Food and Drug Administration (FDA). The coating repelled blood from more than 20 medically relevant substrates the team tested — made of plastic to glass and metal — and also suppressed biofilm formation in a study reported in Nature Biotechnology. But that’s not all.

The team implanted medical-grade tubing and catheters coated with the material in large blood vessels in pigs, and it prevented blood from clotting for at least eight hours without the use of blood thinners such as heparin. Heparin is notorious for causing potentially lethal side-effects like excessive bleeding but is often a necessary evil in medical treatments where clotting is a risk.

“Devising a way to prevent blood clotting without using anticoagulants is one of the holy grails in medicine,” said Don Ingber, M.D., Ph.D., Founding Director of Harvard’s Wyss Institute for Biologically Inspired Engineering and senior author of the study. Ingber is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Boston Children’s Hospital, as well as professor of bioengineering at Harvard School of Engineering and Applied Sciences (SEAS).

An Oct. 12, 2014 Wyss Institute news release (also on EurekAlert), which originated the news item, describes the inspiration for this work,

The idea for the coating evolved from SLIPS, a pioneering surface technology developed by coauthor Joanna Aizenberg, Ph.D., who is a Wyss Institute Core Faculty member and the Amy Smith Berylson Professor of Materials Science at Harvard SEAS. SLIPS stands for Slippery Liquid-Infused Porous Surfaces. Inspired by the slippery surface of the carnivorous pitcher plant, which enables the plant to capture insects, SLIPS repels nearly any material it contacts. The liquid layer on the surface provides a barrier to everything from ice to crude oil and blood.

“Traditional SLIPS uses porous, textured surface substrates to immobilize the liquid layer whereas medical surfaces are mostly flat and smooth – so we further adapted our approach by capitalizing on the natural roughness of chemically modified surfaces of medical devices,” said Aizenberg, who leads the Wyss Institute’s Adaptive Materials platform. “This is yet another incarnation of the highly customizable SLIPS platform that can be designed to create slippery, non-adhesive surfaces on any material.”

The Wyss team developed a super-repellent coating that can be adhered to existing, approved medical devices. In a two-step surface-coating process, they chemically attached a monolayer of perfluorocarbon, which is similar to Teflon. Then they added a layer of liquid perfluorocarbon, which is widely used in medicine for applications such as liquid ventilation for infants with breathing challenges, blood substitution, eye surgery, and more. The team calls the tethered perfluorocarbon plus the liquid layer a Tethered-Liquid Perfluorocarbon surface, or TLP for short.

In addition to working seamlessly when coated on more than 20 different medical surfaces and lasting for more than eight hours to prevent clots in a pig under relatively high blood flow rates without the use of heparin, the TLP coating achieved the following results:

  • TLP-treated medical tubing was stored for more than a year under normal temperature and humidity conditions and still prevented clot formation
  • The TLP surface remained stable under the full range of clinically relevant physiological shear stresses, or rates of blood flow seen in catheters and central lines, all the way up to dialysis machines
  • It repelled the components of blood that cause clotting (fibrin and platelets)
  • When bacteria called Pseudomonas aeruginosa were grown in TLP-coated medical tubing for more than six weeks, less than one in a billion bacteria were able to adhere. Central lines coated with TLP significantly reduce sepsis from Central-Line Mediated Bloodstream Infections (CLABSI). (Sepsis is a life-threatening blood infection caused by bacteria, and a significant risk for patients with implanted medical devices.)

Out of sheer curiosity, the researchers even tested a TLP-coated surface with a gecko – the superstar of sticking whose footpads contain many thousands of hairlike structures with tremendous adhesive strength. The gecko was unable to hold on.

“We were wonderfully surprised by how well the TLP coating worked, particularly in vivo without heparin,” said one of the co-lead authors, Anna Waterhouse, Ph.D., a Wyss Institute Postdoctoral Fellow. “Usually the blood will start to clot within an hour in the extracorporeal circuit, so our experiments really demonstrate the clinical relevance of this new coating.”

While most of the team’s demonstrations were performed on medical devices such as catheters and perfusion tubing using relatively simple setups, they say there is a lot more on the horizon.

“We feel this is just the beginning of how we might test this for use in the clinic,” said co-lead author Daniel Leslie, Ph.D., a Wyss Institute Staff Scientist, who aims to test it on more complex systems such as dialysis machines and ECMO, a machine used in the intensive care unit to help critically ill patients breathe.

I first featured SLIPS technology in a Jan. 15, 2014 post about its possible use for stain-free, self-cleaning clothing. This Wyss Institute video about the latest work featuring the use of  SLIPS technology in medical devices also describes its possible use in pipelines and airplanes,

You can find research paper with this link,

A bioinspired omniphobic surface coating on medical devices prevents thrombosis and biofouling by Daniel C Leslie, Anna Waterhouse, Julia B Berthet, Thomas M Valentin, Alexander L Watters, Abhishek Jain, Philseok Kim, Benjamin D Hatton, Arthur Nedder, Kathryn Donovan, Elana H Super, Caitlin Howell, Christopher P Johnson, Thy L Vu, Dana E Bolgen, Sami Rifai, Anne R Hansen, Michael Aizenberg, Michael Super, Joanna Aizenberg, & Donald E Ingber. Nature Biotechnology (2014) doi:10.1038/nbt.3020 Published online 12 October 2014

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

Ada Lovelace Day tomorrow: Tuesday, Oct. 14, 2014

Tomorrow you can celebrate Ada Lovelace Day 2014. A remarkable thinker, Lovelace (1815 – 1852) suggested computers could be used to create music and art, as well as, other practical activities. By the way, Her father was the ‘mad, bad, and dangerous to know’ poet, Lord Byron who called her mother, Anna Isabelle Millbank (she had a complex set of names and titles), the ‘princess of parallelograms’ due to her (Millbank’s) interest in mathematics.

Thanks to David Bruggeman and an Oct. 8, 2014 post on his Pasco Phronesis blog, I’ve found out about some events planned for this year’s Ada Lovelace Day before the fact rather than the ‘day of’ as I did last year (Oct. 15, 2013 post).

Here’s more from David’s Oct. 8, 2014 post (Note: Links have been removed),

In New York City, one of the commemorations of Ada Lovelace Day involves an opera on her life.  Called Ada, selections will be performed on October 14 [2014].

You can find out more about the opera and the performance on David’s blog post, which also includes video clips from a rehearsal for the opera and comments from the librettist and the composer.

Ada Lovelace Day was founded in 2009 by Suw Charman-Anderson and it’s been gaining momentum ever since. While Charman-Anderson’s Ada Lovelace website doesn’t offer an up-to-date history of the event, there is this about the 2012 celebration (from the History of Ada Lovelace Day page),

… In all, there were 25 independently-organised grassroots events in the UK, Brazil, Canada, Colombia, Italy, Slovenia, Sweden and the USA, as well as online.

This year’s event includes:

Tuesday 14 October 2014

Ada Lovelace Day is an international celebration of the achievements of women in science, technology, engineering and maths (STEM).

Write about an inspiring woman in STEM

Every year we encourage you to take part, no matter where you are, by writing something about a woman, or women, in STEM whose achievements you admire. When your blog post is ready, you can add it to our list, and once we’re properly underway, you’ll be able to browse our list to see who inspires other people!

Ada Lovelace Day Live!

Tickets are now on sale for our amazing evening event [in London, England], featuring mathematician Dr Hannah Fry, musician Caro C, structural engineer Roma Agrawal, geneticist Dr Turi King, TV presenter Konnie Huq, artist Naomi Kashiwagi, technologists Steph Troeth, physicist Dr Helen Czerski and hosted by our inimitable ALD [Ada Lovelace Day] Live producer, Helen Arney!

This event is free for Ri  [Royal Institution] Members and Fellows, £6 for Ri Associates, £8 for Concessions and £12 for everyone else. Buy your tickets nowfind out more about the event or see accessibility information for the venue.

Ada Lovelace Day for Schools

The support of the Ri has this year allowed us to put together an afternoon event for 11 – 16 year olds, exploring the role and work of women in STEM. Speakers include sustainability innovator Rachel Armstrong, neuroscientist Sophie Scott, mathematician Hannah Fry, roboticist and theremin player Sarah Angliss, engineer Roma Agrawal, and dwarf mammoth expert Victoria Herridge, and is hosted by our very own Helen Arney! Tickets cost £3 per person, and are on sale now! [London, England] Find out more about the event or see accessibility information for the venue.

The organizers are currently running an indiegogo crowdfunding campaign (Ada Lovelace Day Live! 2014) to raise £2,000 to cover costs for videography and photography of the events in London, England. They have progressed to a little over 1/2 way towards their goal. The last day to contribute is Oct. 27, 2014.

One last tidbit, James Essinger’s book, Ada’s Algorithm, is being released on Oct. 14, 2014 in the US. The book was published last year in the UK. Sophia Stuart, in an Oct. 10, 2014 article for PC Magazine about the upcoming US release of Essinger’s book, wrote this,

A natural affinity for computer programming requires an unusual blend of arts and sciences; from appreciating the beauty of mathematics and the architectural composition of language via a vision for engineering, coupled with a meticulous attention to detail (and an ability to subsist on little sleep).

Ada Lovelace, considered to be the world’s first computer programmer, fits the profile perfectly, and is the subject of James Essinger’s book Ada’s Algorithm. Ada’s mother was a gifted mathematician and her father was the poet Lord Byron. In 1828, at the age of 12, Ada was multi-lingual while also teaching herself geometry, sketching plans for self-powered flight by studying birds and their wingspan, and imagining the future of aviation 75 years before the Wright Brothers’ first flight.

“In the form of a horse with a steamengine in the inside so contrived as to move an immense pair of wings,” she wrote in an April 7, 1828 letter to her mother.

Don’t forget, Ada Lovelace Day is tomorrow and perhaps in honour of her you can give your imagination permission to fly free for at least a moment or two.

Happy Thanksgiving today, Oct. 13, 2014 for Canadians of all stripes, those who were born here, those who are citizens (past and present), and those who choose to be Canadian in spirit for a day.

Gold nanorods and mucus

Mucus can kill. Most of us are lucky enough to produce mucus appropriate for our bodies’ needs but people who have cystic fibrosis and other kinds of lung disease suffer greatly from mucus that is too thick to pass easily through the body. An Oct. 9, 2014 Optical Society of America (OSA) news release (also on EurekAlert) ‘shines’ a light on the topic of mucus and viscosity,

Some people might consider mucus an icky bodily secretion best left wrapped in a tissue, but to a group of researchers from the University of North Carolina at Chapel Hill, snot is an endlessly fascinating subject. The team has developed a way to use gold nanoparticles and light to measure the stickiness of the slimy substance that lines our airways.  The new method could help doctors better monitor and treat lung diseases such as cystic fibrosis and chronic obstructive pulmonary disease.

“People who are suffering from certain lung diseases have thickened mucus,” explained Amy Oldenburg, a physicist at the University of North Carolina at Chapel Hill whose research focuses on biomedical imaging systems. “In healthy adults, hair-like cell appendages called cilia line the airways and pull mucus out of the lungs and into the throat. But if the mucus is too viscous it can become trapped in the lungs, making breathing more difficult and also failing to remove pathogens that can cause chronic infections.”

Doctors can prescribe mucus-thinning drugs, but have no good way to monitor how the drugs affect the viscosity of mucus at various spots inside the body. This is where Oldenburg and her colleagues’ work may help.

The researchers placed coated gold nanorods on the surface of mucus samples and then tracked the rods’ diffusion into the mucus by illuminating the samples with laser light and analyzing the way the light bounced off the nanoparticles. The slower the nanorods diffused, the thicker the mucus. The team found this imaging method worked even when the mucus was sliding over a layer of cells—an important finding since mucus inside the human body is usually in motion.

“The ability to monitor how well mucus-thinning treatments are working in real-time may allow us to determine better treatments and tailor them for the individual,” said Oldenburg.

It will likely take five to 10 more years before the team’s mucus measuring method is tested on human patients, Oldenburg said. Gold is non-toxic, but for safety reasons the researchers would want to ensure that the gold nanorods would eventually be cleared from a patient’s system.

“This is a great example of interdisciplinary work in which optical scientists can meet a specific need in the clinic,” said Nozomi Nishimura, of Cornell University … . “As these types of optical technologies continue to make their way into medical practice, it will both expand the market for the technology as well as improve patient care.”

The team is also working on several lines of ongoing study that will some day help bring their monitoring device to the clinic. They are developing delivery methods for the gold nanorods, studying how their imaging system might be adapted to enter a patient’s airways, and further investigating how mucus flow properties differ throughout the body.

This work is being presented at:

The research team will present their work at The Optical Society’s (OSA) 98th Annual Meeting, Frontiers in Optics, being held Oct. 19-23 [2014] in Tucson, Arizona, USA.

Presentation FTu5F.2, “Imaging Gold Nanorod Diffusion in Mucus Using Polarization Sensitive OCT,” takes place Tuesday, Oct. 21 at 4:15 p.m. MST [Mountain Standard Time] in the Tucson Ballroom, Salon A at the JW Marriott Tucson Starr Pass Resort.

People with cystic fibrosis tend to have short lives (from the US National Library of Medicine MedLine Plus webpage on cystic fibrosis),

Most children with cystic fibrosis stay in good health until they reach adulthood. They are able to take part in most activities and attend school. Many young adults with cystic fibrosis finish college or find jobs.

Lung disease eventually worsens to the point where the person is disabled. Today, the average life span for people with CF who live to adulthood is about 37 years.

Death is most often caused by lung complications.

I hope this work proves helpful.

Mind-controlled prostheses ready for real world activities

There’s some exciting news from Sweden’s Chalmers University of Technology about prosthetics. From an Oct. 8, 2014 news item on ScienceDaily,

For the first time, robotic prostheses controlled via implanted neuromuscular interfaces have become a clinical reality. A novel osseointegrated (bone-anchored) implant system gives patients new opportunities in their daily life and professional activities.

In January 2013 a Swedish arm amputee was the first person in the world to receive a prosthesis with a direct connection to bone, nerves and muscles. …

An Oct. 8, 2014 Chalmers University press release (also on EurekAlert), which originated the news item, provides more details about the research and this ‘real world’ prosthetic device,

“Going beyond the lab to allow the patient to face real-world challenges is the main contribution of this work,” says Max Ortiz Catalan, research scientist at Chalmers University of Technology and leading author of the publication.

“We have used osseointegration to create a long-term stable fusion between man and machine, where we have integrated them at different levels. The artificial arm is directly attached to the skeleton, thus providing mechanical stability. Then the human’s biological control system, that is nerves and muscles, is also interfaced to the machine’s control system via neuromuscular electrodes. This creates an intimate union between the body and the machine; between biology and mechatronics.”

The direct skeletal attachment is created by what is known as osseointegration, a technology in limb prostheses pioneered by associate professor Rickard Brånemark and his colleagues at Sahlgrenska University Hospital. Rickard Brånemark led the surgical implantation and collaborated closely with Max Ortiz Catalan and Professor Bo Håkansson at Chalmers University of Technology on this project.

The patient’s arm was amputated over ten years ago. Before the surgery, his prosthesis was controlled via electrodes placed over the skin. Robotic prostheses can be very advanced, but such a control system makes them unreliable and limits their functionality, and patients commonly reject them as a result.

Now, the patient has been given a control system that is directly connected to his own. He has a physically challenging job as a truck driver in northern Sweden, and since the surgery he has experienced that he can cope with all the situations he faces; everything from clamping his trailer load and operating machinery, to unpacking eggs and tying his children’s skates, regardless of the environmental conditions (read more about the benefits of the new technology below).

The patient is also one of the first in the world to take part in an effort to achieve long-term sensation via the prosthesis. Because the implant is a bidirectional interface, it can also be used to send signals in the opposite direction – from the prosthetic arm to the brain. This is the researchers’ next step, to clinically implement their findings on sensory feedback.

“Reliable communication between the prosthesis and the body has been the missing link for the clinical implementation of neural control and sensory feedback, and this is now in place,” says Max Ortiz Catalan. “So far we have shown that the patient has a long-term stable ability to perceive touch in different locations in the missing hand. Intuitive sensory feedback and control are crucial for interacting with the environment, for example to reliably hold an object despite disturbances or uncertainty. Today, no patient walks around with a prosthesis that provides such information, but we are working towards changing that in the very short term.”

The researchers plan to treat more patients with the novel technology later this year.

“We see this technology as an important step towards more natural control of artificial limbs,” says Max Ortiz Catalan. “It is the missing link for allowing sophisticated neural interfaces to control sophisticated prostheses. So far, this has only been possible in short experiments within controlled environments.”

The researchers have provided an image of the patient using his prosthetic arm in the context of his work as a truck driver,

[downloaded from http://www.chalmers.se/en/news/Pages/Mind-controlled-prosthetic-arms-that-work-in-daily-life-are-now-a-reality.aspx]

[downloaded from http://www.chalmers.se/en/news/Pages/Mind-controlled-prosthetic-arms-that-work-in-daily-life-are-now-a-reality.aspx]

The news release offers some additional information about the device,

The new technology is based on the OPRA treatment (osseointegrated prosthesis for the rehabilitation of amputees), where a titanium implant is surgically inserted into the bone and becomes fixated to it by a process known as osseointegration (Osseo = bone). A percutaneous component (abutment) is then attached to the titanium implant to serve as a metallic bone extension, where the prosthesis is then fixated. Electrodes are implanted in nerves and muscles as the interfaces to the biological control system. These electrodes record signals which are transmitted via the osseointegrated implant to the prostheses, where the signals are finally decoded and translated into motions.

There are also some videos of the patient demonstrating various aspects of this device available here (keep scrolling) along with more details about what makes this device so special.

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

An osseointegrated human-machine gateway for long-term sensory feedback and motor control of artificial limbs by Max Ortiz-Catalan, Bo Håkansson, and Rickard Brånemark. Sci Transl Med 8 October 2014: Vol. 6, Issue 257, p. 257re6 Sci. Transl. Med. DOI: 10.1126/scitranslmed.3008933

This article is behind a paywall and it appears to be part of a special issue or a special section in an issue, so keep scrolling down the linked to page to find more articles on this topic.

I have written about similar research in the past. Notably, there’s a July 19, 2011 post about work on Intraosseous Transcutaneous Amputation Prosthesis (ITAP) and a May 17, 2012 post featuring a video of a woman reaching with a robotic arm for a cup of coffee using her thoughts alone to control the arm.

Nanoparticle-based radiogenetics to control brain cells

While the title for this post sounds like an opening for a zombie-themed story, this Oct. 8, 2014 news item on Nanowerk actually concerns brain research at Rockefeller University (US), Note: A link has been removed,

A proposal to develop a new way to remotely control brain cells from Sarah Stanley, a Research Associate in Rockefeller University’s Laboratory of Molecular Genetics, headed by Jeffrey M. Friedman, is among the first to receive funding from the BRAIN initiative. The project will make use of a technique called radiogenetics that combines the use of radio waves or magnetic fields with nanoparticles to turn neurons on or off.

An Oct. 7, 2014 Rockefeller University news release, which originated the news item, further describes the BRAIN initiative and the research (Note: Links have been removed),

The NIH [National Institutes of Health]  is one of four federal agencies involved in the BRAIN (Brain Research through Advancing Innovative Neurotechnologies) initiative. Following in the ambitious footsteps of the Human Genome Project, the BRAIN initiative seeks to create a dynamic map of the brain in action, a goal that requires the development of new technologies. The BRAIN initiative working group, which outlined the broad scope of the ambitious project, was co-chaired by Rockefeller’s Cori Bargmann, head of the Laboratory of Neural Circuits and Behavior.

Stanley’s grant, for $1.26 million over three years, is one of 58 projects to get BRAIN grants, the NIH announced. The NIH’s plan for its part of this national project, which has been pitched as “America’s next moonshot,” calls for $4.5 billion in federal funds over 12 years.

The technology Stanley is developing would enable researchers to manipulate the activity of neurons, as well as other cell types, in freely moving animals in order to better understand what these cells do. Other techniques for controlling selected groups of neurons exist, but her new nanoparticle-based technique has a unique combination of features that may enable new types of experimentation. For instance, it would allow researchers to rapidly activate or silence neurons within a small area of the brain or dispersed across a larger region, including those in difficult-to-access locations. Stanley also plans to explore the potential this method has for use treating patients.

“Francis Collins, director of the NIH, has discussed the need for studying the circuitry of the brain, which is formed by interconnected neurons. Our remote-control technology may provide a tool with which researchers can ask new questions about the roles of complex circuits in regulating behavior,” Stanley says.

Here’s an image that Rockefeller University has used to illustrate the concept of radio-controlled brain cells,

 

BRAIN control: The new technology uses radio waves to activate or silence cells remotely. The bright spots above represent cells with increased calcium after treatment with radio waves, a change that would allow neurons to fire. [downloaded from: http://newswire.rockefeller.edu/2014/10/07/rockefeller-neurobiology-lab-is-awarded-first-round-brain-initiative-grant/]

BRAIN control: The new technology uses radio waves to activate or silence cells remotely. The bright spots above represent cells with increased calcium after treatment with radio waves, a change that would allow neurons to fire. [downloaded from: http://newswire.rockefeller.edu/2014/10/07/rockefeller-neurobiology-lab-is-awarded-first-round-brain-initiative-grant/]

You can find out more about the US BRAIN initiative here.

Nanotechnology for better treatment of eye conditions and a perspective on superhuman sight

There are three ‘eye’-related items in this piece, two of them concerning animal eyes and one concerning a camera-eye or the possibility of superhuman sight.

Earlier this week researchers at the University of Reading (UK) announced they have achieved a better understanding of how nanoparticles might be able to bypass some of the eye’s natural barriers in the hopes of making eye drops more effective in an Oct. 7, 2014 news item on Nanowerk,

Sufferers of eye disorders have new hope after researchers at the University of Reading discovered a potential way of making eye drops more effective.

Typically less than 5% of the medicine dose applied as drops actually penetrates the eye – the majority of the dose will be washed off the cornea by tear fluid and lost.

The team, led by Professor Vitaliy Khutoryanskiy, has developed novel nanoparticles that could attach to the cornea and resist the wash out effect for an extended period of time. If these nanoparticles are loaded with a drug, their longer attachment to the cornea will ensure more medicine penetrates the eye and improves drop treatment.

An Oct. 6, 2014 University of Reading press release, which originated the news item, provides more information about the hoped for impact of this work while providing few details about the research (Note: A link has been removed),

The research could also pave the way for new treatments of currently incurable eye-disorders such as Age-related Macular Degeneration (AMD) – the leading cause of visual impairment with around 500,000 sufferers in the UK.

There is currently no cure for this condition but experts believe the progression of AMD could be slowed considerably using injections of medicines into the eye. However, eye-drops with drug-loaded nanoparticles could be a potentially more effective and desirable course of treatment.

Professor Vitaliy Khutoryanskiy, from the University of Reading’s School of Pharmacy, said: “Treating eye disorders is a challenging task. Our corneas allow us to see and serve as a barrier that protects our eyes from microbial and chemical intervention. Unfortunately this barrier hinders the effectiveness of eye drops. Many medicines administered to the eye are inefficient as they often cannot penetrate the cornea barrier. Only the very small molecules in eye drops can penetrate healthy cornea.

“Many recent breakthroughs to treat eye conditions involve the use of drugs incorporated into nano-containers; their role being to promote drug penetration into the eye.  However the factors affecting this penetration remain poorly understood. Our research also showed that penetration of small drug molecules could be improved by adding enhancers such as cyclodextrins. This means eye drops have the potential to be a more effective, and a more comfortable, future treatment for disorders such as AMD.”

The finding is one of a number of important discoveries highlighted in a paper published today in the journal Molecular Pharmaceutics. The researchers revealed fascinating insights into how the structure of the cornea prevents various small and large molecules, as well as nanoparticles, from entering into the eye. They also examined the effects any damage to the eye would have in allowing these materials to enter the body.

Professor Khutoryanskiy continued: “There is increasing concern about the safety of environmental contaminants, pollutants and nanoparticles and their potential impacts on human health. We tested nanoparticles whose sizes ranged between 21 – 69 nm, similar to the size of viruses such as polio, or similar to airborn particles originating from building industry and found that they could not penetrate healthy and intact cornea irrespective of their chemical nature.

“However if the top layer of the cornea is damaged, either after surgical operation or accidentally, then the eye’s natural defence may be compromised and it becomes susceptible to viral attack which could result in eye infections.

“The results show that our eyes are well-equipped to defend us against potential airborne threats that exist in a fast-developing industrialised world. However we need to be aware of the potential complications that may arise if the cornea is damaged, and not treated quickly and effectively.”

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

On the Barrier Properties of the Cornea: A Microscopy Study of the Penetration of Fluorescently Labeled Nanoparticles, Polymers, and Sodium Fluorescein by Ellina A. Mun, Peter W. J. Morrison, Adrian C. Williams, and Vitaliy V. Khutoryanskiy. Mol. Pharmaceutics, 2014, 11 (10), pp 3556–3564 DOI: 10.1021/mp500332m Publication Date (Web): August 28, 2014

Copyright © 2014 American Chemical Society

There’s a little more information to be had in the paper’s abstract, which is, as these things go, is relatively accessible,

[downloaded from http://pubs.acs.org/doi/abs/10.1021/mp500332m]

[downloaded from http://pubs.acs.org/doi/abs/10.1021/mp500332m]

Overcoming the natural defensive barrier functions of the eye remains one of the greatest challenges of ocular drug delivery. Cornea is a chemical and mechanical barrier preventing the passage of any foreign bodies including drugs into the eye, but the factors limiting penetration of permeants and nanoparticulate drug delivery systems through the cornea are still not fully understood. In this study, we investigate these barrier properties of the cornea using thiolated and PEGylated (750 and 5000 Da) nanoparticles, sodium fluorescein, and two linear polymers (dextran and polyethylene glycol). Experiments used intact bovine cornea in addition to bovine cornea de-epithelialized or tissues pretreated with cyclodextrin. It was shown that corneal epithelium is the major barrier for permeation; pretreatment of the cornea with β-cyclodextrin provides higher permeation of low molecular weight compounds, such as sodium fluorescein, but does not enhance penetration of nanoparticles and larger molecules. Studying penetration of thiolated and PEGylated (750 and 5000 Da) nanoparticles into the de-epithelialized ocular tissue revealed that interactions between corneal surface and thiol groups of nanoparticles were more significant determinants of penetration than particle size (for the sizes used here). PEGylation with polyethylene glycol of a higher molecular weight (5000 Da) allows penetration of nanoparticles into the stroma, which proceeds gradually, after an initial 1 h lag phase.

The paper is behind a paywall. No mention is made in the abstract or in the press release as to how the bovine (ox, cow, or buffalo) eyes were obtained but I gather these body parts are often harvested from animals that have been previously slaughtered for food.

This next item also concerns research about eye drops but this time the work comes from the University of Waterloo (Ontario, Canada). From an Oct. 8, 2014 news item on Azonano,

For the millions of sufferers of dry eye syndrome, their only recourse to easing the painful condition is to use drug-laced eye drops three times a day. Now, researchers from the University of Waterloo have developed a topical solution containing nanoparticles that will combat dry eye syndrome with only one application a week.

An Oct. 8, 2014 University of Waterloo news release (also on EurekAlert), which originated the news item, describes the results of the work without providing much detail about the nanoparticles used to deliver the treatment via eye drops,

The eye drops progressively deliver the right amount of drug-infused nanoparticles to the surface of the eyeball over a period of five days before the body absorbs them.  One weekly dose replaces 15 or more to treat the pain and irritation of dry eyes.

The nanoparticles, about 1/1000th the width of a human hair, stick harmlessly to the eye’s surface and use only five per cent of the drug normally required.

“You can’t tell the difference between these nanoparticle eye drops and water,” said Shengyan (Sandy) Liu, a PhD candidate at Waterloo’s Faculty of Engineering, who led the team of researchers from the Department of Chemical Engineering and the Centre for Contact Lens Research. “There’s no irritation to the eye.”

Dry eye syndrome is a more common ailment for people over the age of 50 and may eventually lead to eye damage. More than six per cent of people in the U.S. have it. Currently, patients must frequently apply the medicine three times a day because of the eye’s ability to self-cleanse—a process that washes away 95 per cent of the drug.

“I knew that if we focused on infusing biocompatible nanoparticles with Cyclosporine A, the drug in the eye drops, and make them stick to the eyeball without irritation for longer periods of time, it would also save patients time and reduce the possibility of toxic exposure due to excessive use of eye drops,” said Liu.

The research team is now focusing on preparing the nanoparticle eye drops for clinical trials with the hope that this nanoparticle therapy could reach the shelves of drugstores within five years.

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

Phenylboronic acid modified mucoadhesive nanoparticle drug carriers facilitate weekly treatment of experimentallyinduced dry eye syndrome by Shengyan Liu, Chu Ning Chang, Mohit S. Verma, Denise Hileeto, Alex Muntz, Ulrike Stahl, Jill Woods, Lyndon W. Jones, and Frank X. Gu. Nano Research (October 2014) DOI: 10.1007/s12274-014-0547-3

This paper is behind a paywall. There is a partial preview available for free. As per the paper’s abstract, research was performed on healthy rabbit eyes.

The last ‘sight’ item I’m featuring here comes from the Massachusetts Institute of Technology (MIT) and does not appear to have been occasioned by the publication of a research paper or some other event. From an Oct. 7, 2014 news item on Azonano,

All through his childhood, Ramesh Raskar wished fervently for eyes in the back of his head. “I had the notion that the world did not exist if I wasn’t looking at it, so I would constantly turn around to see if it was there behind me.” Although this head-spinning habit faded during his teen years, Raskar never lost the desire to possess the widest possible field of vision.

Today, as director of the Camera Culture research group and associate professor of Media Arts and Sciences at the MIT Media Lab, Raskar is realizing his childhood fantasy, and then some. His inventions include a nanocamera that operates at the speed of light and do-it-yourself tools for medical imaging. His scientific mission? “I want to create not just a new kind of vision, but superhuman vision,” Raskar says.

An Oct. 6, 2014 MIT news release, which originated the news item, provides more information about Raskar and his research,

He avoids research projects launched with a goal in mind, “because then you only come up with the same solutions as everyone else.” Discoveries tend to cascade from one area into another. For instance, Raskar’s novel computational methods for reducing motion blur in photography suggested new techniques for analyzing how light propagates. “We do matchmaking; what we do here can be used over there,” says Raskar.

Inspired by the famous microflash photograph of a bullet piercing an apple, created in 1964 by MIT professor and inventor Harold “Doc” Edgerton, Raskar realized, “I can do Edgerton millions of times faster.” This led to one of the Camera Culture group’s breakthrough inventions, femtophotography, a process for recording light in flight.

Manipulating photons into a packet resembling Edgerton’s bullet, Raskar and his team were able to “shoot” ultrashort laser pulses through a Coke bottle. Using a special camera to capture the action of these pulses at half a trillion frames per second with two-trillionths of a second exposure times, they captured moving images of light, complete with wave-like shadows lapping at the exterior of the bottle.

Femtophotography opened up additional avenues of inquiry, as Raskar pondered what other features of the world superfast imaging processes might reveal. He was particularly intrigued by scattered light, the kind in evidence when fog creates the visual equivalent of “noise.”

In one experiment, Raskar’s team concealed an object behind a wall, out of camera view. By firing super-short laser bursts onto a surface nearby, and taking millions of exposures of light bouncing like a pinball around the scene, the group rendered a picture of the hidden object. They had effectively created a camera that peers around corners, an invention that might someday help emergency responders safely investigate a dangerous environment.

Raskar’s objective of “making the invisible visible” extends as well to the human body. The Camera Culture group has developed a technique for taking pictures of the eye using cellphone attachments, spawning inexpensive, patient-managed vision and disease diagnostics. Conventional photography has evolved from time-consuming film development to instantaneous digital snaps, and Raskar believes “the same thing will happen to medical imaging.” His research group intends “to break all the rules and be at the forefront. I think we’ll get there in the next few years,” he says.

Ultimately, Raskar predicts, imaging will serve as a catalyst of transformation in all dimensions of human life — change that can’t come soon enough for him. “I hate ordinary cameras,” he says. “They record only what I see. I want a camera that gives me a superhuman perspective.”

Following the link to the MIT news release will lead you to more information about Raskar and his work. You can also see and hear Raskar talk about his femtophotography in a 2012 TEDGlobal talk here.

Female triathlete from Iran and a nanotechnology solution to water repellent gear

The style is a bit breathless, i.e., a high level of hype with very little about the technology, but it features an interesting partnership in the world of sport and a nanotechnology-enabled product (from an Oct. 7, 2014 news item on Azonano; Note: A link has been removed),

Shirin Gerami’s story is one which will go down in history. Shirin is the first Iranian female to represent her country in a triathlon and is paving the way for setting gender equality both in Iran and across the world.

In order to race for Iran, it was essential that Shirin respected the rules of her country, and raced in clothes that covered her body and hair. It was necessary to design clothes those both adhered to these conditions, whilst ensuring her performance was not affected.

An Oct. 7, 2014 P2i press release, which originated the news item, goes on to describe it role in Shirin Gerami athletic career,

Previously, waterproof fabrics Shirin had tried were uncomfortable, lacked breathability and slowed down her performance. Shirin contacted P2i upon hearing of the liquid repellent qualities of our patented nano-technology. Our nano-technology, a thousand times thinner than a human hair, has no effect on the look or feel of a product. This means we can achieve the highest levels of water repellency without affecting the quality of a fabric. A P2i coating on the kit meant it was water repellent whilst remaining highly breathable and light – essential when trying to remain as streamlined as possible!

Here’s a picture of Gerami wearing her new gear at a recently held triathlete event held in Edmonton, Alberta, Canada,

[downloaded from http://www.p2i.com/news/articles/P2i_and_Shirin_Gerami_A_partnership_changing_history]

[downloaded from http://www.p2i.com/news/articles/P2i_and_Shirin_Gerami_A_partnership_changing_history]

The press release describes her first experience with her P2i-enabled running gear (Note: A link has been removed),

Shirin only received approval for her race kit from the Iranian government days before the race, so it was quite literally a race to the starting line. Consequently, Shirin did not have time to test the P2i coated kit before she began the World Triathlon Grand Final in Edmonton, Canada. Shirin explains, ‘I cannot tell you how relieved and happy I am that the coating worked exactly as I hoped it would. It was bone dry when I took my wetsuit off!’

I believe Gerami is using the term ‘wetsuit’ as a way of identifying the kit’s skintight properties similar to the ‘wetsuits’ that divers wear.

The press release concludes (Note: A link has been removed),

You can find out more about UK-based P2i on its website. I was not able to find more information about its products designed for use in sports gear but was able to find a May 11, 2012 press release about its partnership with UK Sport.

As for the Aug. 25 – Sept. 1, 2014 TransCanada Corp. World Triathlon Grand Final where Gerami tested her suit, you can find out more about the event here (scroll down).

Nanoscopy and a 2014 Nobel Prize for Chemistry

An Oct. 8, 2014 news item on Nanowerk features the 2014 Nobel Prize in Chemistry honourees,

 For a long time optical microscopy was held back by a presumed limitation: that it would never obtain a better resolution than half the wavelength of light. Helped by fluorescent molecules the Nobel Laureates in Chemistry 2014 ingeniously circumvented this limitation.

Their ground-breaking work has brought optical microscopy into the nanodimension.
In what has become known as nanoscopy, scientists visualize the pathways of individual molecules inside living cells. They can see how molecules create synapses between nerve cells in the brain; they can track proteins involved in Parkinson’s, Alzheimer’s and Huntington’s diseases as they aggregate; they follow individual proteins in fertilized eggs as these divide into embryos.

An Oct, 8, 2014 Royal Swedish Academy of Science press release, which originated the news item, expands on the ‘groundbreaking’ theme,

It was all but obvious that scientists should ever be able to study living cells in the tiniest molecular detail. In 1873, the microscopist Ernst Abbe stipulated a physical limit for the maximum resolution of traditional optical microscopy: it could never become better than 0.2 micrometres. Eric Betzig, Stefan W. Hell and William E. Moerner are awarded the Nobel Prize in Chemistry 2014 for having bypassed this limit. Due to their achievements the optical microscope can now peer into the nanoworld.

Two separate principles are rewarded. One enables the method stimulated emission depletion (STED) microscopy, developed by Stefan Hell in 2000. Two laser beams are utilized; one stimulates fluorescent molecules to glow, another cancels out all fluorescence except for that in a nanometre-sized volume. Scanning over the sample, nanometre for nanometre, yields an image with a resolution better than Abbe’s stipulated limit.

Eric Betzig and William Moerner, working separately, laid the foundation for the second method, single-molecule microscopy. The method relies upon the possibility to turn the fluorescence of individual molecules on and off. Scientists image the same area multiple times, letting just a few interspersed molecules glow each time. Superimposing these images yields a dense super-image resolved at the nanolevel. In 2006 Eric Betzig utilized this method for the first time.

Today, nanoscopy is used world-wide and new knowledge of greatest benefit to mankind is produced on a daily basis.

Here’s an image illustrating different microscopy resolutions including one featuring single-molecule microscopy,

The centre image shows lysosome membranes and is one of the first ones taken by Betzig using single-molecule microscopy. To the left, the same image taken using conventional microscopy. To the right, the image of the membranes has been enlarged. Note the scale division of 0.2 micrometres, equivalent to Abbe’s diffraction limit. Image: Science 313:1642–1645. [downloaded from http://www.kva.se/en/pressroom/Press-releases-2014/nobelpriset-i-kemi-2014/]

The centre image shows lysosome membranes and is one of the first ones taken by Betzig using single-molecule microscopy. To the left, the same image taken using conventional microscopy. To the right, the image of the membranes has been enlarged. Note the scale division of 0.2 micrometres, equivalent to Abbe’s diffraction limit. Image: Science 313:1642–1645. [downloaded from http://www.kva.se/en/pressroom/Press-releases-2014/nobelpriset-i-kemi-2014/]

The press release goes on to provide some biographical details about the three honourees and information about the financial size of the award,

Eric Betzig, U.S. citizen. Born 1960 in Ann Arbor, MI, USA. Ph.D. 1988 from Cornell University, Ithaca, NY, USA. Group Leader at Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.

Stefan W. Hell, German citizen. Born 1962 in Arad, Romania. Ph.D. 1990 from the University of Heidelberg, Germany. Director at the Max Planck Institute for Biophysical Chemistry, Göttingen, and Division head at the German Cancer Research Center, Heidelberg, Germany.

William E. Moerner, U.S. citizen. Born 1953 in Pleasanton, CA, USA. Ph.D. 1982 from Cornell University, Ithaca, NY, USA. Harry S. Mosher Professor in Chemistry and Professor, by courtesy, of Applied Physics at Stanford University, Stanford, CA, USA.

Prize amount: SEK 8 million, to be shared equally between the Laureates.

The amount is in Swedish Krona. In USD, it is approximately $1.1M; in CAD, it is approximately $1.2M; and, in pounds sterling (British pounds), it is approximately £689,780.

Congratulations to all three gentlemen!

ETA Oct. 14, 2014: Azonano features an Oct. 14, 2014 news item from the UK’s National Physical Laboratory (NPL)  congratulating the three recipients of the 2014 Nobel Prize for Chemistry. The item also features a description of the recipients’ groundbreaking work along with an update on how this pioneering work has influenced and inspired further research in the field of nanoscopy at the NPL.