Category Archives: energy

Low-cost carbon sequestration and eco-friendly manufacturing for chemicals with nanobio hybrid organisms

Years ago I was asked about carbon sequestration and nanotechnology and could not come up with any examples. At last I have something for the next time the question is asked. From a June 11, 2019 news item on ScienceDaily,

University of Colorado Boulder researchers have developed nanobio-hybrid organisms capable of using airborne carbon dioxide and nitrogen to produce a variety of plastics and fuels, a promising first step toward low-cost carbon sequestration and eco-friendly manufacturing for chemicals.

By using light-activated quantum dots to fire particular enzymes within microbial cells, the researchers were able to create “living factories” that eat harmful CO2 and convert it into useful products such as biodegradable plastic, gasoline, ammonia and biodiesel.

A June 11, 2019 University of Colorado at Boulder news release (also on EurekAlert) by Trent Knoss, which originated the news item, provides a deeper dive into the research,

“The innovation is a testament to the power of biochemical processes,” said Prashant Nagpal, lead author of the research and an assistant professor in CU Boulder’s Department of Chemical and Biological Engineering. “We’re looking at a technique that could improve CO2 capture to combat climate change and one day even potentially replace carbon-intensive manufacturing for plastics and fuels.”

The project began in 2013, when Nagpal and his colleagues began exploring the broad potential of nanoscopic quantum dots, which are tiny semiconductors similar to those used in television sets. Quantum dots can be injected into cells passively and are designed to attach and self-assemble to desired enzymes and then activate these enzymes on command using specific wavelengths of light.

Nagpal wanted to see if quantum dots could act as a spark plug to fire particular enzymes within microbial cells that have the means to convert airborne CO2 and nitrogen, but do not do so naturally due to a lack of photosynthesis.

By diffusing the specially-tailored dots into the cells of common microbial species found in soil, Nagpal and his colleagues bridged the gap. Now, exposure to even small amounts of indirect sunlight would activate the microbes’ CO2 appetite, without a need for any source of energy or food to carry out the energy-intensive biochemical conversions.

“Each cell is making millions of these chemicals and we showed they could exceed their natural yield by close to 200 percent,” Nagpal said.

The microbes, which lie dormant in water, release their resulting product to the surface, where it can be skimmed off and harvested for manufacturing. Different combinations of dots and light produce different products: Green wavelengths cause the bacteria to consume nitrogen and produce ammonia while redder wavelengths make the microbes feast on CO2 to produce plastic instead.

The process also shows promising signs of being able to operate at scale. The study found that even when the microbial factories were activated consistently for hours at a time, they showed few signs of exhaustion or depletion, indicating that the cells can regenerate and thus limit the need for rotation.

“We were very surprised that it worked as elegantly as it did,” Nagpal said. “We’re just getting started with the synthetic applications.”

The ideal futuristic scenario, Nagpal said, would be to have single-family homes and businesses pipe their CO2 emissions directly to a nearby holding pond, where microbes would convert them to a bioplastic. The owners would be able to sell the resulting product for a small profit while essentially offsetting their own carbon footprint.

“Even if the margins are low and it can’t compete with petrochemicals on a pure cost basis, there is still societal benefit to doing this,” Nagpal said. “If we could convert even a small fraction of local ditch ponds, it would have a sizeable impact on the carbon output of towns. It wouldn’t be asking much for people to implement. Many already make beer at home, for example, and this is no more complicated.”

The focus now, he said, will shift to optimizing the conversion process and bringing on new undergraduate students. Nagpal is looking to convert the project into an undergraduate lab experiment in the fall semester, funded by a CU Boulder Engineering Excellence Fund grant. Nagpal credits his current students with sticking with the project over the course of many years.

“It has been a long journey and their work has been invaluable,” he said. “I think these results show that it was worth it.”

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

Nanorg Microbial Factories: Light-Driven Renewable Biochemical Synthesis Using Quantum Dot-Bacteria Nanobiohybrids by Yuchen Ding, John R. Bertram, Carrie Eckert, Rajesh Reddy Bommareddy, Rajan Patel, Alex Conradie, Samantha Bryan, Prashant Nagpal. J. Am. Chem. Soc.2019XXXXXXXXXX-XXX DOI: https://doi.org/10.1021/jacs.9b02549 Publication Date:June 7, 2019
Copyright © 2019 American Chemical Society

This paper is behind a paywall.

‘Smart’ windows in Vancouver (Canada): engineering issues?

This post was going to focus on the first building in Canada to feature ‘smart’ windows. In this case, they are electrochromic windows and the company, View Dynamic Glass, was mentioned here in a September 17, 2018 posting about the windows’ use at the Dallas/Fort Worth Airport. (The posting includes a link to the View Dynamic Glass report on the windows’ use and a short video.)

However, things changed but, first, let’s start with an explanation as to what electrochromic glass ir. Chris Woodford in a December 5, 2018 article on explainthatstuff.com offers a great overview which includes an explanation, a description of how they work, and more. What follows is a brief excerpt from Woodford’s overview (Note: Links have been removed),

What is electrochromic glass?

Glass is an amazing material and our buildings would be dark, dingy, cold, and damp without it. But it has its drawbacks too. It lets in light and heat even when you don’t want it to. On a blinding summer’s day, the more heat (“solar gain”) that enters your building the more you’ll need to use your air-conditioning—a horrible waste of energy that costs you money and harms the environment. That’s why most of the windows in homes and offices are fitted with curtains or blinds. If you’re into interior design and remodeling, you might think furnishings like this are neat and attractive—but in cold, practical, scientific terms they’re a nuisance. Let’s be honest about this: curtains and blinds are a technological kludge to make up for glass’s big, built-in drawback: it’s transparent (or translucent) even when you don’t want it to be.

Since the early 20th century, people have got used to the idea of buildings that are increasingly automated. We have electric clothes washing machines, dishwashers, vacuum cleaners and much more. So why not fit our homes with electric windows that can change from clear to dark automatically? Smart windows (also referred to by the names smart glass, switchable windows, and dynamic windows) do exactly that using a scientific idea called electrochromism, in which materials change color (or switch from transparent to opaque) when you apply an electrical voltage across them. Typically smart windows start off a blueish color and gradually (over a few minutes) turn transparent when the electric current passes through them.

As for the news about its Vancouver debut, I was very excited to see this April 28, 2019 article by Kenneth Chan for dailyhive.com/vancouver,

BlueSky Properties’ 10-storey office building at 988 West Broadway [in Vancouver, Canada; emphasis mine] is home to the new Vancouver offices of Industrial Alliance Financial Group, which has leased nine stories and 93,700-sq-ft of office space.



One of the building’s unique design features is its use of View Dynamic Glass technology [emphases mine] — a glass technology that controls heat and glare, reduces overall energy consumption and costs, and improves the health and wellness of individuals working inside the building.

These smart windows optimize the amount of natural light to enhance mental and physical well-being without the need for shades or blinds. The application of the technology on this building, the first of its kind in Canada, will result in energy savings of up to 20%, [emphasis mine] with the amount of sunlight streaming through automatically tinted to block glare.

Blue Sky Properties (a Bosa Family Company), the local developer for this building, was very excited about the building and the ‘smart’ glass technology, according to its April 23, 2019 news release (here for a short version and here for the full version).

Other than being happy to see the technology being employed in Vancouver, I didn’t spend a lot of time thinking about the property. That changed on reading a May 8, 2019 article by Kenneth Chan for dailyhive.com/vancouver,

A structural engineer based in Vancouver has been stripped of his license to work in British Columbia [emphasis mine] following an investigation that determined his design for a condominium tower in Surrey fell short of the provincial building code.

According to a disciplinary notice posted by Engineers and Geoscientists British Columbia Association (EGBCA) on April 30, John Bryson, a managing partner of Bryson Markulin Zickmantel Structural Engineers (BMZSE), [emphases mine] admitted to unprofessional conduct and acted contrary to the association’s code of ethics that requires its members to “hold paramount the safety, health, and welfare of the public.”

“Mr. Bryson admitted that his structural design for the building did not comply with the 2006 BC Building Code, to which he certified it had been designed, in particular with respect to seismic and wind loads,” reads the notice. [emphases mine]

BMZSE has been involved in the design work of a number of projects across Metro Vancouver, including Station Square, Rogers Arena South Tower, Lougheed Heights, River District Parcel 17, The Jervis, Harwood, Plaza 88, Solo District, Burrard Place, Centreview Place, Trump International Hotel & Tower Vancouver, Central, Sovereign, Kings Crossing, and 988 West Broadway. [emphases mine]

You can find the ‘disciplinary notice’ (it’s an account of what Bryson failed to do and the punishment for the failure) here on the Association of Professional Engineers and Geoscientists of the Province of British Columbia (also known as Engineers and Geoscientists British Columbia) website.

Presumably, all of Bryson’s projects have been reviewed since the disciplinary action.

Graphene and smart textiles

Here’s one of the more recent efforts to create fibres that are electronic and capable of being woven into a smart textile. (Details about a previous effort can be found at the end of this post.) Now for this one, from a Dec. 3, 2018 news item on ScienceDaily,

The quest to create affordable, durable and mass-produced ‘smart textiles’ has been given fresh impetus through the use of the wonder material Graphene.

An international team of scientists, led by Professor Monica Craciun from the University of Exeter Engineering department, has pioneered a new technique to create fully electronic fibres that can be incorporated into the production of everyday clothing.

A Dec. 3, 2018 University of Exeter press release (also on EurekAlert), provides more detail about the problems associated with wearable electronics and the solution being offered (Note: A link has been removed),

Currently, wearable electronics are achieved by essentially gluing devices to fabrics, which can mean they are too rigid and susceptible to malfunctioning.

The new research instead integrates the electronic devices into the fabric of the material, by coating electronic fibres with light-weight, durable components that will allow images to be shown directly on the fabric.

The research team believe that the discovery could revolutionise the creation of wearable electronic devices for use in a range of every day applications, as well as health monitoring, such as heart rates and blood pressure, and medical diagnostics.

The international collaborative research, which includes experts from the Centre for Graphene Science at the University of Exeter, the Universities of Aveiro and Lisbon in Portugal, and CenTexBel in Belgium, is published in the scientific journal Flexible Electronics.

Professor Craciun, co-author of the research said: “For truly wearable electronic devices to be achieved, it is vital that the components are able to be incorporated within the material, and not simply added to it.

Dr Elias Torres Alonso, Research Scientist at Graphenea and former PhD student in Professor Craciun’s team at Exeter added “This new research opens up the gateway for smart textiles to play a pivotal role in so many fields in the not-too-distant future.  By weaving the graphene fibres into the fabric, we have created a new technique to all the full integration of electronics into textiles. The only limits from now are really within our own imagination.”

At just one atom thick, graphene is the thinnest substance capable of conducting electricity. It is very flexible and is one of the strongest known materials. The race has been on for scientists and engineers to adapt graphene for the use in wearable electronic devices in recent years.

This new research used existing polypropylene fibres – typically used in a host of commercial applications in the textile industry – to attach the new, graphene-based electronic fibres to create touch-sensor and light-emitting devices.

The new technique means that the fabrics can incorporate truly wearable displays without the need for electrodes, wires of additional materials.

Professor Saverio Russo, co-author and from the University of Exeter Physics department, added: “The incorporation of electronic devices on fabrics is something that scientists have tried to produce for a number of years, and is a truly game-changing advancement for modern technology.”

Dr Ana Neves, co-author and also from Exeter’s Engineering department added “The key to this new technique is that the textile fibres are flexible, comfortable and light, while being durable enough to cope with the demands of modern life.”

In 2015, an international team of scientists, including Professor Craciun, Professor Russo and Dr Ana Neves from the University of Exeter, have pioneered a new technique to embed transparent, flexible graphene electrodes into fibres commonly associated with the textile industry.

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

Graphene electronic fibres with touch-sensing and light-emitting functionalities for smart textiles by Elias Torres Alonso, Daniela P. Rodrigues, Mukond Khetani, Dong-Wook Shin, Adolfo De Sanctis, Hugo Joulie, Isabel de Schrijver, Anna Baldycheva, Helena Alves, Ana I. S. Neves, Saverio Russo & Monica F. Craciun. Flexible Electronicsvolume 2, Article number: 25 (2018) DOI: https://doi.org/10.1038/s41528-018-0040-2 Published 25 September 2018

This paper is open access.

I have an earlier post about an effort to weave electronics into textiles for soldiers, from an April 5, 2012 posting,

I gather that today’s soldier (aka, warfighter)  is carrying as many batteries as weapons. Apparently, the average soldier carries a couple of kilos worth of batteries and cables to keep their various pieces of equipment operational. The UK’s Centre for Defence Enterprise (part of the Ministry of Defence) has announced that this situation is about to change as a consequence of a recently funded research project with a company called Intelligent Textiles. From Bob Yirka’s April 3, 2012 news item for physorg.com,

To get rid of the cables, a company called Intelligent Textiles has come up with a type of yarn that can conduct electricity, which can be woven directly into the fabric of the uniform. And because they allow the uniform itself to become one large conductive unit, the need for multiple batteries can be eliminated as well.

I dug down to find more information about this UK initiative and the Intelligent Textiles company but the trail seems to end in 2015. Still, I did find a Canadian connection (for those who don’t know I’m a Canuck) and more about Intelligent Textile’s work with the British military in this Sept. 21, 2015 article by Barry Collins for alphr.com (Note: Links have been removed),

A two-person firm operating from a small workshop in Staines-upon-Thames, Intelligent Textiles has recently landed a multimillion-pound deal with the US Department of Defense, and is working with the Ministry of Defence (MoD) to bring its potentially life-saving technology to British soldiers. Not bad for a company that only a few years ago was selling novelty cushions.

Intelligent Textiles was born in 2002, almost by accident. Asha Peta Thompson, an arts student at Central Saint Martins, had been using textiles to teach children with special needs. That work led to a research grant from Brunel University, where she was part of a team tasked with creating a “talking jacket” for the disabled. The garment was designed to help cerebral palsy sufferers to communicate, by pressing a button on the jacket to say “my name is Peter”, for example, instead of having a Stephen Hawking-like communicator in front of them.

Another member of that Brunel team was engineering lecturer Dr Stan Swallow, who was providing the electronics expertise for the project. Pretty soon, the pair realised the prototype waistcoat they were working on wasn’t going to work: it was cumbersome, stuffed with wires, and difficult to manufacture. “That’s when we had the idea that we could weave tiny mechanical switches into the surface of the fabric,” said Thompson.

The conductive weave had several advantages over packing electronics into garments. “It reduces the amount of cables,” said Thompson. “It can be worn and it’s also washable, so it’s more durable. It doesn’t break; it can be worn next to the skin; it’s soft. It has all the qualities of a piece of fabric, so it’s a way of repackaging the electronics in a way that’s more user-friendly and more comfortable.” The key to Intelligent Textiles’ product isn’t so much the nature of the raw materials used, but the way they’re woven together. “All our patents are in how we weave the fabric,” Thompson explained. “We weave two conductive yarns to make a tiny mechanical switch that is perfectly separated or perfectly connected. We can weave an electronic circuit board into the fabric itself.”

Intelligent Textiles’ big break into the military market came when they met a British textiles firm that was supplying camouflage gear to the Canadian armed forces. [emphasis mine] The firm was attending an exhibition in Canada and invited the Intelligent Textiles duo to join them. “We showed a heated glove and an iPod controller,” said Thompson. “The Canadians said ‘that’s really fantastic, but all we need is power. Do you think you could weave a piece of fabric that distributes power?’ We said, ‘we’re already doing it’.”Before long it wasn’t only power that the Canadians wanted transmitted through the fabric, but data.

“The problem a soldier faces at the moment is that he’s carrying 60 AA batteries [to power all the equipment he carries],” said Thompson. “He doesn’t know what state of charge those batteries are at, and they’re incredibly heavy. He also has wires and cables running around the system. He has snag hazards – when he’s going into a firefight, he can get caught on door handles and branches, so cables are a real no-no.”

The Canadians invited the pair to speak at a NATO conference, where they were approached by military brass with more familiar accents. “It was there that we were spotted by the British MoD, who said ‘wow, this is a British technology but you’re being funded by Canada’,” said Thompson. That led to £235,000 of funding from the Centre for Defence Enterprise (CDE) – the money they needed to develop a fabric wiring system that runs all the way through the soldier’s vest, helmet and backpack.

There are more details about the 2015 state of affairs, textiles-wise, in a March 11, 2015 article by Richard Trenholm for CNET.com (Note: A link has been removed),

Speaking at the Wearable Technology Show here, Swallow describes IT [Intelligent Textiles]L as a textile company that “pretends to be a military company…it’s funny how you slip into these domains.”

One domain where this high-tech fabric has seen frontline action is in the Canadian military’s IAV Stryker armoured personnel carrier. ITL developed a full QWERTY keyboard in a single piece of fabric for use in the Stryker, replacing a traditional hardware keyboard that involved 100 components. Multiple components allow for repair, but ITL knits in redundancy so the fabric can “degrade gracefully”. The keyboard works the same as the traditional hardware, with the bonus that it’s less likely to fall on a soldier’s head, and with just one glaring downside: troops can no longer use it as a step for getting in and out of the vehicle.

An armoured car with knitted controls is one thing, but where the technology comes into its own is when used about the person. ITL has worked on vests like the JTAC, a system “for the guys who call down airstrikes” and need “extra computing oomph.” Then there’s SWIPES, a part of the US military’s Nett Warrior system — which uses a chest-mounted Samsung Galaxy Note 2 smartphone — and British military company BAE’s Broadsword system.

ITL is currently working on Spirit, a “truly wearable system” for the US Army and United States Marine Corps. It’s designed to be modular, scalable, intuitive and invisible.

While this isn’t an ITL product, this video about Broadsword technology from BAE does give you some idea of what wearable technology for soldiers is like,

baesystemsinc

Uploaded on Jul 8, 2014

Broadsword™ delivers groundbreaking technology to the 21st Century warfighter through interconnecting components that inductively transfer power and data via The Spine™, a revolutionary e-textile that can be inserted into any garment. This next-generation soldier system offers enhanced situational awareness when used with the BAE Systems’ Q-Warrior® see-through display.

If anyone should have the latest news about Intelligent Textile’s efforts, please do share in the comments section.

I do have one other posting about textiles and the military, which is dated May 9, 2012, but while it does reference US efforts it is not directly related to weaving electronics into solder’s (warfighter’s) gear.

You can find CenTexBel (Belgian Textile Rsearch Centre) here and Graphenea here. Both are mentioned in the University of Exeter press release.

Unusual appetite for gold

This bacterium (bacteria being the plural) loves gold, which is lucky for anyone trying to develop artificial photosynthesis.From an October 9, 2018 news item on ScienceDaily,

A bacterium named Moorella thermoacetica won’t work for free. But UC Berkeley [University of California at Berkeley] researchers have figured out it has an appetite for gold. And in exchange for this special treat, the bacterium has revealed a more efficient path to producing solar fuels through artificial photosynthesis.

An October 5, 2018 UC Berkeley news release by Theresa Duque (also on EurekAlert but published on October 9, 2018), which originated the news item, expands on the theme,

M. thermoacetica first made its debut as the first non-photosensitive bacterium to carry out artificial photosynthesis (link is external) in a study led by Peidong Yang, a professor in UC Berkeley’s College of Chemistry. By attaching light-absorbing nanoparticles made of cadmium sulfide (CdS) to the bacterial membrane exterior, the researchers turned M. thermoacetica into a tiny photosynthesis machine, converting sunlight and carbon dioxide into useful chemicals.

Now Yang and his team of researchers have found a better way to entice this CO2-hungry bacterium into being even more productive. By placing light-absorbing gold nanoclusters inside the bacterium, they have created a biohybrid system that produces a higher yield of chemical products than previously demonstrated. The research, funded by the National Institutes of Health, was published on Oct. 1 in Nature Nanotechnology (link is external).

For the first hybrid model, M. thermoacetica-CdS, the researchers chose cadmium sulfide as the semiconductor for its ability to absorb visible light. But because cadmium sulfide is toxic to bacteria, the nanoparticles had to be attached to the cell membrane “extracellularly,” or outside the M. thermoacetica-CdS system. Sunlight excites each cadmium-sulfide nanoparticle into generating a charged particle known as an electron. As these light-generated electrons travel through the bacterium, they interact with multiple enzymes in a process known as “CO2 reduction,” triggering a cascade of reactions that eventually turns CO2 into acetate, a valuable chemical for making solar fuels.

But within the extracellular model, the electrons end up interacting with other chemicals that have no part in turning CO2 into acetate. And as a result, some electrons are lost and never reach the enzymes. So to improve what’s known as “quantum efficiency,” or the bacterium’s ability to produce acetate each time it gains an electron, the researchers found another semiconductor: nanoclusters made of 22 gold atoms (Au22), a material that M. thermoacetica took a surprising shine to.

A single nanocluster of 22 gold atoms

Figure: A single nanocluster of 22 gold atoms – Au22 – is only 1 nanometer in diameter, allowing it to easily slip through the bacterial cell wall.

“We selected Au22 because it’s ideal for absorbing visible light and has the potential for driving the CO2 reduction process, but we weren’t sure whether it would be compatible with the bacteria,” Yang said. “When we inspected them under the microscope, we discovered that the bacteria were loaded with these Au22 clusters – and were still happily alive.”

Imaging of the M. thermoacetica-Au22 system was done at UC Berkeley’s Molecular Imaging Center (link is external).

The researchers also selected Au22 ­– dubbed by the researchers as “magic” gold nanoclusters – for its ultrasmall size: A single Au22nanocluster is only 1 nanometer in diameter, allowing each nanocluster to easily slip through the bacterial cell wall.

“By feeding bacteria with Au22 nanoclusters, we’ve effectively streamlined the electron transfer process for the CO2 reduction pathway inside the bacteria, as evidenced by a 2.86 percent quantum efficiency – or 33 percent more acetate produced within the M. thermoacetica-Au22 system than the CdS model,” Yang said.

The magic gold nanocluster is the latest discovery coming out of Yang’s lab, which for the past six years has focused on using biohybrid nanostructures to convert CO2 into useful chemicals as part of an ongoing effort to find affordable, abundant resources for renewable fuels, and potential solutions to thwart the effects of climate change.

“Next, we’d like to find a way to reduce costs, improve the lifetimes for these biohybrid systems, and improve quantum efficiency,” Yang said. “By continuing to look at the fundamental aspect of how gold nanoclusters are being photoactivated, and by following the electron transfer process within the CO2 reduction pathway, we hope to find even better solutions.”

Co-authors with Yang are UC Berkeley graduate student Hao Zhang and former postdoctoral fellow Hao Liu, now at Donghua University in Shanghai, China.

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

Bacteria photosensitized by intracellular gold nanoclusters for solar fuel production by Hao Zhang, Hao Liu, Zhiquan Tian, Dylan Lu, Yi Yu, Stefano Cestellos-Blanco, Kelsey K. Sakimoto, & Peidong Yang. Nature Nanotechnologyvolume 13, pages900–905 (2018). DOI: https://doi.org/10.1038/s41565-018-0267-z Published: 01 October 2018

This paper is behind a paywall.

For lovers of animation, the folks at UC Berkeley have produced this piece about the ‘gold-loving’ bacterium,

The van Gogh-Roosegaarde path, a solar powered bike path

From YouTube, Heijmans NV Published on Nov 12, 2014 Inspired by Vincent van Gogh’s work, the cycle path combines innovation and design with cultural heritage and tourism. The Van Gogh-Roosegaarde cycle path is being constructed by Heijmans from a design by Daan Roosegaarde and forms part of the Van Gogh cycle route in Brabant.

According to other sources, the path was inspired by van Gogh’s ‘Starry Night’. From a November 21, 2014 article by Elizabeth Montalbano for Design News (Note: A link has been removed),

The Dutch are known for their love of bicycling, and they’ve also long been early adopters of green-energy and smart-city technologies. So it seems fitting that a town in which painter Vincent van Gogh once lived has given him a very Dutch-like tribute — a bike path lit by a special smart paint in the style of the artist’s “Starry Night” painting.

Designed by artist Daan Roosegaarde of Studio Roosegaarde, the van Gogh-Roosegaarde bike path — in the Dutch town of Nuenen en Eindhoven, where van Gogh lived from 1883-1885 — is a kilometer long and features technologies developed as part of the Smart Highway project, a joint venture of the studio and Dutch infrastructure company Heijmans.

A team of 12 designers and engineers worked on the project for eight months, while site production took 10 days. The opening of the path marked the official launch of the international van Gogh 2015 year.

The path uses stones painted with a smart coating that charges by the heat of the sun during the day and then glow at night for up to eight hours. When there is not enough sunlight during the day to charge the stones, the path can draw electricity from a solar panel installed nearby. There are also LEDs in the path that provides lighting.

How does the technology work?

Despite my best efforts, I never did unearth a good technical explanation. There is some sort of photoluminescent powder or paint. I vote for a powder that’s been emulsified in a paint/coating. material. Somehow, this material is charged by sunlight and then at night glows with the help of a solar panel and light-emitting diodes (LEDs).

Here’s the clearest explanation I found; it’s from Dan Howarth’s November 12, 2014 article for dezeen.com (Note: A link has been removed), ,

The surface of the Van Gogh-Roosegaarde Bicycle Path is coated with a special paint that uses energy gathered during the day to glow after dark.


[Daan] Roosegaarde told Dezeen that this method of illumination is “more gentle to the eye and surrounding nature” that other lighting infrastructure, and creates a “connection with cultural history”.

A nearby solar panel is used to generate power to illuminate the coated surface, which was developed with infrastructure firm Heijmans. LEDs along the side of certain curves in the path cast extra light, meaning the path will still be partially lit if the weather has been too cloudy for the panel to charge the surface to its full brightness.

“It’s a new total system that is self-sufficient and practical, and just incredibly poetic,” said Roosegaarde.

Lily Hay Newman’s November 14, 2014 article for Slate.com succinctly sums up the technical aspects,

The path is coated in photoluminescent paint that’s also embedded with small LEDs powered by nearby solar panels. The path essentially charges all day so that it can glow during the night, and it also has backup power in case it’s overcast.

This October 30, 2012 article by Liat Clark for Wired.com provides a bit more detail about the powder/paint as Clark delves into the Roosegaarde Studo’s Smart Highway project (the cycle path made use of the same technology) ,

The studio has developed a photo-luminising powder that will replace road markings – it charges up in sunlight, giving it up to 10 hours of glow-in-the-dark time come nightfall. “It’s like the glow in the dark paint you and I had when we were children,” designer Roosegaarde explained, “but we teamed up with a paint manufacturer and pushed the development. Now, it’s almost radioactive“. [perhaps not the wisest choice of hyperbole]

Special paint will also be used to paint markers like snowflakes across the road’s surface – when temperatures fall to a certain point, these images will become visible, indicating that the surface will likely be slippery. Roosegaarde says this technology has been around for years, on things like baby food – the studio has just upscaled it.

Not everyone is in love

Shaunacy Ferro’s July 26, 2017 article for dentalfloss.com highlights a glow-in-the-dark path project for Singapore and a little criticism (Note: Links have been removed),

Glow-in-the-dark materials are no longer for toys. Photoluminescence can help cities feel safer at night, whether it’s part of a mural, a bike lane, or a highway. Glow-in-the-dark paths have been tested in several European cities (the above is a Van Gogh-inspired bike path by the Dutch artist Daan Roosegaarde) and in Texas, but now, the technology may be coming to Singapore. The city-state is currently developing a 15-mile greenway called the Rail Corridor, and it now has a glow-in-the-dark path, as Mashable reports.

The 328-foot stretch of glowing path is part of a test of multiple surface materials that might eventually be used throughout the park, depending on public opinion. In addition to the strontium aluminate-beaded [emphasis mine] path that glows at night, there are also three other 328-foot stretches of the path that are paved with fine gravel, cement aggregate, and part-grass/part-gravel. The glow-in-the-dark material embedded in the walkway absorbs UV light from the sun during the day and can emit light for up to eight hours once the sun goes down.

However, in practice, glow-in-the-dark paths can be less dazzling than they seem. [emphasis mine] Mashable’s reporter called the glowing effect on Singapore’s path “disappointingly feeble.” [emphasis mine] In 2014, a glowing highway-markings pilot by Studio Roosegaarde in the Netherlands revealed that the first road markings faded after exposure to heavy rains. [emphases mine] When it comes to glowing roads, the renderings tend to look better than the actual result, [emphasis mine] and there are still kinks to work out. (The studio worked the issue out eventually.) While a person walking or biking down Singapore’s glowing path might be able to tell that they were staying on the path better than if they were fumbling along dark pavement, it’s not the equivalent of a streetlight, for sure.

Ferro had reported earlier on Studio Roosegaarde’s Smart Highway project in an October 23, 2014 article for Fast Company where Ferro first mentioned the rain problem (Note: Links have been removed),

Glowing Lanes is a collaboration between Dutch engineering company Heijmans and Daan Roosegaarde, a tech-loving artist and designer whose previous work includes Intimacy 2.0, a dress that becomes transparent when the wearer gets aroused. The glow-in-the-dark lane markers are intended to increase road visibility in a more energy-efficient way than traditional street lighting. Photoluminescent paint charges during the day and slowly emits light over the course of eight hours during the evening.

After a few technical challenges (an early version of the markers didn’t fare so well in the rain), the final system has been installed, and according to Studio Roosegaarde, the kinks have been worked out, and initial reports of the paint fading were “overstated.” [emphases mine]

“This was part of any normal learning process,” according to an email from the studio’s PR, and “now the project is ‘matured.’”

But not to the point where it’s no longer a novelty. According to the email from Studio Roosegaarde, the glowing highway caused a minor traffic jam last night as people rushed to look at it.

… Roosegaarde has also been asked to create a smart highway design for Afsluitdijk–an almost 20-mile-long dike that connects North Holland to the province of Friesland across the water–and according to his studio, there are plans in the works to launch the glowing lanes in China and Japan as well.

Comments

In the following excerpt, there’s a reference to strontium aluminate-coated materials, given the interview which follows this section, the project in Singapore did not use the photoluminescent paint developed by Roosegaarde Studio. I found this paint reference in a July 26, 2017 article by Yi Shu Ng for Mashable (h/t Ferro’s July 26, 2017 article) which notes the product’s ubiquity,

The track glows because it’s got strontium aluminate compounds embedded in it — the chemical is commonly found in glow-in-the-dark products, which absorb ultraviolet light in the day, to emit luminescence at night.

There are some inconsistencies in the reporting about the number of hours, eight hours or 10 hours, the bicycle path or smart highway remains lit after being charged. Given that this was a newish technology being used in a new application, the rain problem and other technical glitches were to be expected. I wish the writer had been a little less dismissive and that the studio had been a little more forthcoming about how they solved the problems. In any case, I dug further and this is what I got.

Interview

I’m not sure who answered the questions but this comes direct from Studio Roosegaarde,

  • Could you give me a capsule description of what’s happened since the path was opened in 2014/15? For example, How does the bike path look these days? Does it still glow? Don’t the bicycles on the path destroy the ‘Starry Night’ pattern over time? Do the stones have to be coated over and over again to maintain their solar charging capacities? 

    The Van Gogh Path is still working perfectly and is visited every night by couples, tourists and local people. The stones are inside the concrete so are still in place and will work for a minimum of 10 years. It is great to see we have created a place of wonder. It is the most published bicycle path in the world. We have even had children books published about it.
  • Are there more bike paths like the Van Gogh Path in other parts of Holland and/or elsewhere?

    No, this is the only one. There have been some copycats in other countries.The Smart Highway project is still growing, and our recent Gates of Light is the next step of poetic and energy-neutral landscapes like the Van Gogh Path:  https://www.studioroosegaarde.net/project/gates-of-light
  • How has your project evolved? And, have there been any unanticipated benefits and/or setbacks? Is there a change in the technology, I noticed you were investigating bioluminscence.

    Yes, we are still developing new landscapes of the future. What we have learned from Van Gogh Path we have applied in new projects such as Glowing Nature: https://www.studioroosegaarde.net/project/glowing-nature We also do something new.
  • I was struck by how gentle the lighting is. I understand there has been some criticism about how much light the path radiates and I’m wondering about your thoughts on that.

    Yes, since the path is a nature protected environment, normal LED lighting was not allowed. So the light is gentle but still visible, and sustainable.There are some bad copy-cats using cheap materials which don’t work well, like the one in Singapore. But we are happy that our path is still working.

Thank you to the folks at Studio Roosegaarde for taking the time to provide this interview. Here are links to Studio Roosegaarde and their industrial partner, Heijmans.

Iridescent giant clams could point the way to safety, climatologically speaking

Giant clams in Palau (Cynthia Barnett)

These don’t look like any clams I’ve ever seen but that is the point of Cynthia Barnett’s absorbing Sept. 10, 2018 article for The Atlantic (Note: A link has been removed),

Snorkeling amid the tree-tangled rock islands of Ngermid Bay in the western Pacific nation of Palau, Alison Sweeney lingers at a plunging coral ledge, photographing every giant clam she sees along a 50-meter transect. In Palau, as in few other places in the world, this means she is going to be underwater for a skin-wrinkling long time.

At least the clams are making it easy for Sweeney, a biophysicist at the University of Pennsylvania. The animals plump from their shells like painted lips, shimmering in blues, purples, greens, golds, and even electric browns. The largest are a foot across and radiate from the sea floor, but most are the smallest of the giant clams, five-inch Tridacna crocea, living higher up on the reef. Their fleshy Technicolor smiles beam in all directions from the corals and rocks of Ngermid Bay.

… Some of the corals are bleached from the conditions in Ngermid Bay, where naturally high temperatures and acidity mirror the expected effects of climate change on the global oceans. (Ngermid Bay is more commonly known as “Nikko Bay,” but traditional leaders and government officials are working to revive the indigenous name of Ngermid.)

Even those clams living on bleached corals are pulsing color, like wildflowers in a white-hot desert. Sweeney’s ponytail flows out behind her as she nears them with her camera. They startle back into their fluted shells. Like bashful fairytale creatures cursed with irresistible beauty, they cannot help but draw attention with their sparkly glow.

Barnett makes them seem magical and perhaps they are (Note: A link has been removed),

It’s the glow that drew Sweeney’s attention to giant clams, and to Palau, a tiny republic of more than 300 islands between the Philippines and Guam. Its sun-laden waters are home to seven of the world’s dozen giant-clam species, from the storied Tridacna gigas—which can weigh an estimated 550 pounds and measure over four feet across—to the elegantly fluted Tridacna squamosa. Sweeney first came to the archipelago in 2009, while working on animal iridescence as a post-doctoral fellow at the University of California at Santa Barbara. Whether shimmering from a blue morpho butterfly’s wings or a squid’s skin, iridescence is almost always associated with a visual signal—one used to attract mates or confuse predators. Giant clams’ luminosity is not such a signal. So, what is it?

In the years since, Sweeney and her colleagues have discovered that the clams’ iridescence is essentially the outer glow of a solar transformer—optimized over millions of years to run on sunlight and algal biofuel. Giant clams reach their cartoonish proportions thanks to an exceptional ability to grow their own photosynthetic algae in vertical farms spread throughout their flesh. Sweeney and other scientists think this evolved expertise may shed light on alternative fuel technologies and other industrial solutions for a warming world.

Barnett goes on to describe Palau’s relationship to the clams and the clams’ environment,

Palau’s islands have been inhabited for at least 3,400 years, and from the start, giant clams were a staple of diet, daily life, and even deity. Many of the islands’ oldest-surviving tools are crafted of thick giant-clam shell: arched-blade adzes, fishhooks, gougers, heavy taro-root pounders. Giant-clam shell makes up more than three-fourths of some of the oldest shell middens in Palau, a percentage that decreases through the centuries. Archaeologists suggest that the earliest islanders depleted the giant clams that crowded the crystalline shallows, then may have self-corrected. Ancient Palauan conservation law, known as bul, prohibited fishing during critical spawning periods, or when a species showed signs of over-harvesting.

Before the Christianity that now dominates Palauan religion sailed in on eighteenth-century mission ships, the culture’s creation lore began with a giant clam called to life in an empty sea. The clam grew bigger and bigger until it sired Latmikaik, the mother of human children, who birthed them with the help of storms and ocean currents.

The legend evokes giant clams in their larval phase, moving with the currents for their first two weeks of life. Before they can settle, the swimming larvae must find and ingest one or two photosynthetic alga, which later multiply, becoming self-replicating fuel cells. After the larvae down the alga and develop a wee shell and a foot, they kick around like undersea farmers, looking for a sunny spot for their crop. When they’ve chosen a well-lit home in a shallow lagoon or reef, they affix to the rock, their shell gaping to the sky. After the sun hits and photosynthesis begins, the microalgae will multiply to millions, or in the case of T. gigas, billions, and clam and algae will live in symbiosis for life.

Giant clam is a beloved staple in Palau and many other Pacific islands, prepared raw with lemon, simmered into coconut soup, baked into a savory pancake, or sliced and sautéed in a dozen other ways. But luxury demand for their ivory-like shells and their adductor muscle, which is coveted as high-end sashimi and an alleged aphrodisiac, has driven T. gigas extinct in China, Taiwan, and other parts of their native habitat. Some of the toughest marine-protection laws in the world, along with giant-clam aquaculture pioneered here, have helped Palau’s wild clams survive. The Palau Mariculture Demonstration Center raises hundreds of thousands of giant clams a year, supplying local clam farmers who sell to restaurants and the aquarium trade and keeping pressure off the wild population. But as other nations have wiped out their clams, Palau’s 230,000-square-mile ocean territory is an increasing target of illegal foreign fishers.

Barnett delves into how the country of Palau is responding to the voracious appetite for the giant clams and other marine life,

Palau, drawing on its ancient conservation tradition of bul, is fighting back. In 2015, President Tommy Remengesau Jr. signed into law the Palau National Marine Sanctuary Act, which prohibits fishing in 80 percent of Palau’s Exclusive Economic Zone and creates a domestic fishing area in the remaining 20 percent, set aside for local fishers selling to local markets. In 2016, the nation received a $6.6 million grant from Japan to launch a major renovation of the Palau Mariculture Demonstration Center. Now under construction at the waterfront on the southern tip of Malakal Island, the new facility will amp up clam-aquaculture research and increase giant-clam production five-fold, to more than a million seedlings a year.

Last year, Palau amended its immigration policy to require that all visitors sign a pledge to behave in an ecologically responsible manner. The pledge, stamped into passports by an immigration officer who watches you sign, is written to the island’s children:

Children of Palau, I take this pledge, as your guest, to preserve and protect your beautiful and unique island home. I vow to tread lightly, act kindly and explore mindfully. I shall not take what is not given. I shall not harm what does not harm me. The only footprints I shall leave are those that will wash away.

The pledge is winning hearts and public-relations awards. But Palau’s existential challenge is still the collective “we,” the world’s rising carbon emissions and the resulting upturns in global temperatures, sea levels, and destructive storms.

F. Umiich Sengebau, Palau’s Minister for Natural Resources, Environment, and Tourism, grew up on Koror and is full of giant-clam proverbs, wisdom and legends from his youth. He tells me a story I also heard from an elder in the state of Airai: that in old times, giant clams were known as “stormy-weather food,” the fresh staple that was easy to collect and have on hand when it was too stormy to go out fishing.

As Palau faces the storms of climate change, Sengebau sees giant clams becoming another sort of stormy-weather food, serving as a secure source of protein; a fishing livelihood; a glowing icon for tourists; and now, an inspiration for alternative energy and other low-carbon technologies. “In the old days, clams saved us,” Sengebau tells me. “I think there’s a lot of power in that, a great power and meaning in the history of clams as food, and now clams as science.”

I highly recommend Barnett’s article, which is one article in a larger series, from a November 6, 2017 The Atlantic press release,

The Atlantic is expanding the global footprint of its science writing today with a multi-year series to investigate life in all of its multitudes. The series, “Life Up Close,” created with support from Howard Hughes Medical Institute’s Department of Science Education (HHMI), begins today at TheAtlantic.com. In the first piece for the project, “The Zombie Diseases of Climate Change,” The Atlantic’s Robinson Meyer travels to Greenland to report on the potentially dangerous microbes emerging from thawing Arctic permafrost.

The project is ambitious in both scope and geographic reach, and will explore how life is adapting to our changing planet. Journalists will travel the globe to examine these changes as they happen to microbes, plants, and animals in oceans, grasslands, forests, deserts, and the icy poles. The Atlantic will question where humans should look for life next: from the Martian subsurface, to Europa’s oceans, to the atmosphere of nearby stars and beyond. “Life Up Close” will feature at least twenty reported pieces continuing through 2018.

“The Atlantic has been around for 160 years, but that’s a mere pinpoint in history when it comes to questions of life and where it started, and where we’re going,” said Ross Andersen, The Atlantic’s senior editor who oversees science, tech, and health. “The questions that this project will set out to tackle are critical; and this support will allow us to cover new territory in new and more ambitious ways.”

About The Atlantic:
Founded in 1857 and today one of the fastest growing media platforms in the industry, The Atlantic has throughout its history championed the power of big ideas and continues to shape global debate across print, digital, events, and video platforms. With its award-winning digital presence TheAtlantic.com and CityLab.com on cities around the world, The Atlantic is a multimedia forum on the most critical issues of our times—from politics, business, urban affairs, and the economy, to technology, arts, and culture. The Atlantic is celebrating its 160th anniversary this year. Bob Cohn is president of The Atlantic and Jeffrey Goldberg is editor in chief.

About the Howard Hughes Medical Institute (HHMI) Department of Science Education:
HHMI is the leading private nonprofit supporter of scientific research and science education in the United States. The Department of Science Education’s BioInteractive division produces free, high quality educational media for science educators and millions of students around the globe, its HHMI Tangled Bank Studios unit crafts powerful stories of scientific discovery for television and big screens, and its grants program aims to transform science education in universities and colleges. For more information, visit www.hhmi.org.

Getting back to the giant clams, sometimes all you can do is marvel, eh?

Bristly hybrid materials

Caption: [Image 1] A carbon fiber covered with a spiky forest of NiCoHC nanowires. Credit: All images reproduced from reference 1 under a Creative Commons Attribution 4.0 International License© 2018 KAUST

It makes me think of small, cuddly things like cats and dogs but it’s not. From an August 7, 2018 King Abdullah University of Science and Technology (KAUST; Saudi Arabia) news release (also published on August 12, 2018 on EurekAlert),

By combining multiple nanomaterials into a single structure, scientists can create hybrid materials that incorporate the best properties of each component and outperform any single substance. A controlled method for making triple-layered hollow nanostructures has now been developed at KAUST. The hybrid structures consist of a conductive organic core sandwiched between layers of electrocatalytically active metals: their potential uses range from better battery electrodes to renewable fuel production.

Although several methods exist to create two-layer materials, making three-layered structures has proven much more difficult, says Peng Wang from the Water Desalination and Reuse Center who co-led the current research with Professor Yu Han, member of the Advanced Membranes and Porous Materials Center at KAUST. The researchers developed a new, dual-template approach, explains Sifei Zhuo, a postdoctoral member of Wang’s team.

The researchers grew their hybrid nanomaterial directly on carbon paper–a mat of electrically conductive carbon fibers. They first produced a bristling forest of nickel cobalt hydroxyl carbonate (NiCoHC) nanowires onto the surface of each carbon fiber (image 1). Each tiny inorganic bristle was coated with an organic layer called hydrogen substituted graphdiyne (HsGDY) (image 2 [not included here]).

Next was the key dual-template step. When the team added a chemical mixture that reacts with the inner NiCoHC, the HsGDY acted as a partial barrier. Some nickel and cobalt ions from the inner layer diffused outward, where they reacted with thiomolybdate from the surrounding solution to form the outer nickel-, cobalt-co-doped MoS2 (Ni,Co-MoS2) layer. Meanwhile, some sulfur ions from the added chemicals diffused inwards to react with the remaining nickel and cobalt. The resulting substance (image 3 [not included here]) had the structure Co9S8, Ni3S2@HsGDY@Ni,Co-MoS2, in which the conductive organic HsGDY layer is sandwiched between two inorganic layers (image 4 [not included here]).

The triple layer material showed good performance at electrocatalytically breaking up water molecules to generate hydrogen, a potential renewable fuel. The researchers also created other triple-layer materials using the dual-template approach

“These triple-layered nanostructures hold great potential in energy conversion and storage,” says Zhuo. “We believe it could be extended to serve as a promising electrode in many electrochemical applications, such as in supercapacitors and sodium-/lithium-ion batteries, and for use in water desalination.”

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

Dual-template engineering of triple-layered nanoarray electrode of metal chalcogenides sandwiched with hydrogen-substituted graphdiyne by Sifei Zhuo, Yusuf Shi, Lingmei Liu, Renyuan Li, Le Shi, Dalaver H. Anjum, Yu Han, & Peng Wang. Nature Communicationsvolume 9, Article number: 3132 (2018) DOI: https://doi.org/10.1038/s41467-018-05474-0 Published 07 August 2018

This paper is open access.

 

Bringing memristors to the masses and cutting down on energy use

One of my earliest posts featuring memristors (May 9, 2008) focused on their potential for energy savings but since then most of my postings feature research into their application in the field of neuromorphic (brainlike) computing. (For a description and abbreviated history of the memristor go to this page on my Nanotech Mysteries Wiki.)

In a sense this July 30, 2018 news item on Nanowerk is a return to the beginning,

A new way of arranging advanced computer components called memristors on a chip could enable them to be used for general computing, which could cut energy consumption by a factor of 100.

This would improve performance in low power environments such as smartphones or make for more efficient supercomputers, says a University of Michigan researcher.

“Historically, the semiconductor industry has improved performance by making devices faster. But although the processors and memories are very fast, they can’t be efficient because they have to wait for data to come in and out,” said Wei Lu, U-M professor of electrical and computer engineering and co-founder of memristor startup Crossbar Inc.

Memristors might be the answer. Named as a portmanteau of memory and resistor, they can be programmed to have different resistance states–meaning they store information as resistance levels. These circuit elements enable memory and processing in the same device, cutting out the data transfer bottleneck experienced by conventional computers in which the memory is separate from the processor.

A July 30, 2018 University of Michigan news release (also on EurekAlert), which originated the news item, expands on the theme,

… unlike ordinary bits, which are 1 or 0, memristors can have resistances that are on a continuum. Some applications, such as computing that mimics the brain (neuromorphic), take advantage of the analog nature of memristors. But for ordinary computing, trying to differentiate among small variations in the current passing through a memristor device is not precise enough for numerical calculations.

Lu and his colleagues got around this problem by digitizing the current outputs—defining current ranges as specific bit values (i.e., 0 or 1). The team was also able to map large mathematical problems into smaller blocks within the array, improving the efficiency and flexibility of the system.

Computers with these new blocks, which the researchers call “memory-processing units,” could be particularly useful for implementing machine learning and artificial intelligence algorithms. They are also well suited to tasks that are based on matrix operations, such as simulations used for weather prediction. The simplest mathematical matrices, akin to tables with rows and columns of numbers, can map directly onto the grid of memristors.

The memristor array situated on a circuit board.

The memristor array situated on a circuit board. Credit: Mohammed Zidan, Nanoelectronics group, University of Michigan.

Once the memristors are set to represent the numbers, operations that multiply and sum the rows and columns can be taken care of simultaneously, with a set of voltage pulses along the rows. The current measured at the end of each column contains the answers. A typical processor, in contrast, would have to read the value from each cell of the matrix, perform multiplication, and then sum up each column in series.

“We get the multiplication and addition in one step. It’s taken care of through physical laws. We don’t need to manually multiply and sum in a processor,” Lu said.

His team chose to solve partial differential equations as a test for a 32×32 memristor array—which Lu imagines as just one block of a future system. These equations, including those behind weather forecasting, underpin many problems science and engineering but are very challenging to solve. The difficulty comes from the complicated forms and multiple variables needed to model physical phenomena.

When solving partial differential equations exactly is impossible, solving them approximately can require supercomputers. These problems often involve very large matrices of data, so the memory-processor communication bottleneck is neatly solved with a memristor array. The equations Lu’s team used in their demonstration simulated a plasma reactor, such as those used for integrated circuit fabrication.

This work is described in a study, “A general memristor-based partial differential equation solver,” published in the journal Nature Electronics.

It was supported by the Defense Advanced Research Projects Agency (DARPA) (grant no. HR0011-17-2-0018) and by the National Science Foundation (NSF) (grant no. CCF-1617315).

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

A general memristor-based partial differential equation solver by Mohammed A. Zidan, YeonJoo Jeong, Jihang Lee, Bing Chen, Shuo Huang, Mark J. Kushner & Wei D. Lu. Nature Electronicsvolume 1, pages411–420 (2018) DOI: https://doi.org/10.1038/s41928-018-0100-6 Published: 13 July 2018

This paper is behind a paywall.

For the curious, Dr. Lu’s startup company, Crossbar can be found here.

A solar, self-charging supercapacitor for wearable technology

Ravinder Dahiya, Carlos García Núñez, and their colleagues at the University of Glasgow (Scotland) strike again (see my May 10, 2017 posting for their first ‘solar-powered graphene skin’ research announcement). Last time it was all about robots and prosthetics, this time they’ve focused on wearable technology according to a July 18, 2018 news item on phys.org,

A new form of solar-powered supercapacitor could help make future wearable technologies lighter and more energy-efficient, scientists say.

In a paper published in the journal Nano Energy, researchers from the University of Glasgow’s Bendable Electronics and Sensing Technologies (BEST) group describe how they have developed a promising new type of graphene supercapacitor, which could be used in the next generation of wearable health sensors.

A July 18, 2018 University of Glasgow press release, which originated the news item, explains further,

Currently, wearable systems generally rely on relatively heavy, inflexible batteries, which can be uncomfortable for long-term users. The BEST team, led by Professor Ravinder Dahiya, have built on their previous success in developing flexible sensors by developing a supercapacitor which could power health sensors capable of conforming to wearer’s bodies, offering more comfort and a more consistent contact with skin to better collect health data.

Their new supercapacitor uses layers of flexible, three-dimensional porous foam formed from graphene and silver to produce a device capable of storing and releasing around three times more power than any similar flexible supercapacitor. The team demonstrated the durability of the supercapacitor, showing that it provided power consistently across 25,000 charging and discharging cycles.

They have also found a way to charge the system by integrating it with flexible solar powered skin already developed by the BEST group, effectively creating an entirely self-charging system, as well as a pH sensor which uses wearer’s sweat to monitor their health.

Professor Dahiya said: “We’re very pleased by the progress this new form of solar-powered supercapacitor represents. A flexible, wearable health monitoring system which only requires exposure to sunlight to charge has a lot of obvious commercial appeal, but the underlying technology has a great deal of additional potential.

“This research could take the wearable systems for health monitoring to remote parts of the world where solar power is often the most reliable source of energy, and it could also increase the efficiency of hybrid electric vehicles. We’re already looking at further integrating the technology into flexible synthetic skin which we’re developing for use in advanced prosthetics.” [emphasis mine]

In addition to the team’s work on robots, prosthetics, and graphene ‘skin’ mentioned in the May 10, 2017 posting the team is working on a synthetic ‘brainy’ skin for which they have just received £1.5m funding from the Engineering and Physical Science Research Council (EPSRC).

Brainy skin

A July 3, 2018 University of Glasgow press release discusses the proposed work in more detail,

A robotic hand covered in ‘brainy skin’ that mimics the human sense of touch is being developed by scientists.

University of Glasgow’s Professor Ravinder Dahiya has plans to develop ultra-flexible, synthetic Brainy Skin that ‘thinks for itself’.

The super-flexible, hypersensitive skin may one day be used to make more responsive prosthetics for amputees, or to build robots with a sense of touch.

Brainy Skin reacts like human skin, which has its own neurons that respond immediately to touch rather than having to relay the whole message to the brain.

This electronic ‘thinking skin’ is made from silicon based printed neural transistors and graphene – an ultra-thin form of carbon that is only an atom thick, but stronger than steel.

The new version is more powerful, less cumbersome and would work better than earlier prototypes, also developed by Professor Dahiya and his Bendable Electronics and Sensing Technologies (BEST) team at the University’s School of Engineering.

His futuristic research, called neuPRINTSKIN (Neuromorphic Printed Tactile Skin), has just received another £1.5m funding from the Engineering and Physical Science Research Council (EPSRC).

Professor Dahiya said: “Human skin is an incredibly complex system capable of detecting pressure, temperature and texture through an array of neural sensors that carry signals from the skin to the brain.

“Inspired by real skin, this project will harness the technological advances in electronic engineering to mimic some features of human skin, such as softness, bendability and now, also sense of touch. This skin will not just mimic the morphology of the skin but also its functionality.

“Brainy Skin is critical for the autonomy of robots and for a safe human-robot interaction to meet emerging societal needs such as helping the elderly.”

Synthetic ‘Brainy Skin’ with sense of touch gets £1.5m funding. Photo of Professor Ravinder Dahiya

This latest advance means tactile data is gathered over large areas by the synthetic skin’s computing system rather than sent to the brain for interpretation.

With additional EPSRC funding, which extends Professor Dahiya’s fellowship by another three years, he plans to introduce tactile skin with neuron-like processing. This breakthrough in the tactile sensing research will lead to the first neuromorphic tactile skin, or ‘brainy skin.’

To achieve this, Professor Dahiya will add a new neural layer to the e-skin that he has already developed using printing silicon nanowires.

Professor Dahiya added: “By adding a neural layer underneath the current tactile skin, neuPRINTSKIN will add significant new perspective to the e-skin research, and trigger transformations in several areas such as robotics, prosthetics, artificial intelligence, wearable systems, next-generation computing, and flexible and printed electronics.”

The Engineering and Physical Sciences Research Council (EPSRC) is part of UK Research and Innovation, a non-departmental public body funded by a grant-in-aid from the UK government.

EPSRC is the main funding body for engineering and physical sciences research in the UK. By investing in research and postgraduate training, the EPSRC is building the knowledge and skills base needed to address the scientific and technological challenges facing the nation.

Its portfolio covers a vast range of fields from healthcare technologies to structural engineering, manufacturing to mathematics, advanced materials to chemistry. The research funded by EPSRC has impact across all sectors. It provides a platform for future UK prosperity by contributing to a healthy, connected, resilient, productive nation.

It’s fascinating to note how these pieces of research fit together for wearable technology and health monitoring and creating more responsive robot ‘skin’ and, possibly, prosthetic devices that would allow someone to feel again.

The latest research paper

Getting back the solar-charging supercapacitors mentioned in the opening, here’s a link to and a citation for the team’s latest research paper,

Flexible self-charging supercapacitor based on graphene-Ag-3D graphene foam electrodes by Libu Manjakka, Carlos García Núñez, Wenting Dang, Ravinder Dahiya. Nano Energy Volume 51, September 2018, Pages 604-612 DOI: https://doi.org/10.1016/j.nanoen.2018.06.072

This paper is open access.

Brainy and brainy: a novel synaptic architecture and a neuromorphic computing platform called SpiNNaker

I have two items about brainlike computing. The first item hearkens back to memristors, a topic I have been following since 2008. (If you’re curious about the various twists and turns just enter  the term ‘memristor’ in this blog’s search engine.) The latest on memristors is from a team than includes IBM (US), École Politechnique Fédérale de Lausanne (EPFL; Swizterland), and the New Jersey Institute of Technology (NJIT; US). The second bit comes from a Jülich Research Centre team in Germany and concerns an approach to brain-like computing that does not include memristors.

Multi-memristive synapses

In the inexorable march to make computers function more like human brains (neuromorphic engineering/computing), an international team has announced its latest results in a July 10, 2018 news item on Nanowerk,

Two New Jersey Institute of Technology (NJIT) researchers, working with collaborators from the IBM Research Zurich Laboratory and the École Polytechnique Fédérale de Lausanne, have demonstrated a novel synaptic architecture that could lead to a new class of information processing systems inspired by the brain.

The findings are an important step toward building more energy-efficient computing systems that also are capable of learning and adaptation in the real world. …

A July 10, 2018 NJIT news release (also on EurekAlert) by Tracey Regan, which originated by the news item, adds more details,

The researchers, Bipin Rajendran, an associate professor of electrical and computer engineering, and S. R. Nandakumar, a graduate student in electrical engineering, have been developing brain-inspired computing systems that could be used for a wide range of big data applications.

Over the past few years, deep learning algorithms have proven to be highly successful in solving complex cognitive tasks such as controlling self-driving cars and language understanding. At the heart of these algorithms are artificial neural networks – mathematical models of the neurons and synapses of the brain – that are fed huge amounts of data so that the synaptic strengths are autonomously adjusted to learn the intrinsic features and hidden correlations in these data streams.

However, the implementation of these brain-inspired algorithms on conventional computers is highly inefficient, consuming huge amounts of power and time. This has prompted engineers to search for new materials and devices to build special-purpose computers that can incorporate the algorithms. Nanoscale memristive devices, electrical components whose conductivity depends approximately on prior signaling activity, can be used to represent the synaptic strength between the neurons in artificial neural networks.

While memristive devices could potentially lead to faster and more power-efficient computing systems, they are also plagued by several reliability issues that are common to nanoscale devices. Their efficiency stems from their ability to be programmed in an analog manner to store multiple bits of information; however, their electrical conductivities vary in a non-deterministic and non-linear fashion.

In the experiment, the team showed how multiple nanoscale memristive devices exhibiting these characteristics could nonetheless be configured to efficiently implement artificial intelligence algorithms such as deep learning. Prototype chips from IBM containing more than one million nanoscale phase-change memristive devices were used to implement a neural network for the detection of hidden patterns and correlations in time-varying signals.

“In this work, we proposed and experimentally demonstrated a scheme to obtain high learning efficiencies with nanoscale memristive devices for implementing learning algorithms,” Nandakumar says. “The central idea in our demonstration was to use several memristive devices in parallel to represent the strength of a synapse of a neural network, but only chose one of them to be updated at each step based on the neuronal activity.”

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

Neuromorphic computing with multi-memristive synapses by Irem Boybat, Manuel Le Gallo, S. R. Nandakumar, Timoleon Moraitis, Thomas Parnell, Tomas Tuma, Bipin Rajendran, Yusuf Leblebici, Abu Sebastian, & Evangelos Eleftheriou. Nature Communications volume 9, Article number: 2514 (2018) DOI: https://doi.org/10.1038/s41467-018-04933-y Published 28 June 2018

This is an open access paper.

Also they’ve got a couple of very nice introductory paragraphs which I’m including here, (from the June 28, 2018 paper in Nature Communications; Note: Links have been removed),

The human brain with less than 20 W of power consumption offers a processing capability that exceeds the petaflops mark, and thus outperforms state-of-the-art supercomputers by several orders of magnitude in terms of energy efficiency and volume. Building ultra-low-power cognitive computing systems inspired by the operating principles of the brain is a promising avenue towards achieving such efficiency. Recently, deep learning has revolutionized the field of machine learning by providing human-like performance in areas, such as computer vision, speech recognition, and complex strategic games1. However, current hardware implementations of deep neural networks are still far from competing with biological neural systems in terms of real-time information-processing capabilities with comparable energy consumption.

One of the reasons for this inefficiency is that most neural networks are implemented on computing systems based on the conventional von Neumann architecture with separate memory and processing units. There are a few attempts to build custom neuromorphic hardware that is optimized to implement neural algorithms2,3,4,5. However, as these custom systems are typically based on conventional silicon complementary metal oxide semiconductor (CMOS) circuitry, the area efficiency of such hardware implementations will remain relatively low, especially if in situ learning and non-volatile synaptic behavior have to be incorporated. Recently, a new class of nanoscale devices has shown promise for realizing the synaptic dynamics in a compact and power-efficient manner. These memristive devices store information in their resistance/conductance states and exhibit conductivity modulation based on the programming history6,7,8,9. The central idea in building cognitive hardware based on memristive devices is to store the synaptic weights as their conductance states and to perform the associated computational tasks in place.

The two essential synaptic attributes that need to be emulated by memristive devices are the synaptic efficacy and plasticity. …

It gets more complicated from there.

Now onto the next bit.

SpiNNaker

At a guess, those capitalized N’s are meant to indicate ‘neural networks’. As best I can determine, SpiNNaker is not based on the memristor. Moving on, a July 11, 2018 news item on phys.org announces work from a team examining how neuromorphic hardware and neuromorphic software work together,

A computer built to mimic the brain’s neural networks produces similar results to that of the best brain-simulation supercomputer software currently used for neural-signaling research, finds a new study published in the open-access journal Frontiers in Neuroscience. Tested for accuracy, speed and energy efficiency, this custom-built computer named SpiNNaker, has the potential to overcome the speed and power consumption problems of conventional supercomputers. The aim is to advance our knowledge of neural processing in the brain, to include learning and disorders such as epilepsy and Alzheimer’s disease.

A July 11, 2018 Frontiers Publishing news release on EurekAlert, which originated the news item, expands on the latest work,

“SpiNNaker can support detailed biological models of the cortex–the outer layer of the brain that receives and processes information from the senses–delivering results very similar to those from an equivalent supercomputer software simulation,” says Dr. Sacha van Albada, lead author of this study and leader of the Theoretical Neuroanatomy group at the Jülich Research Centre, Germany. “The ability to run large-scale detailed neural networks quickly and at low power consumption will advance robotics research and facilitate studies on learning and brain disorders.”

The human brain is extremely complex, comprising 100 billion interconnected brain cells. We understand how individual neurons and their components behave and communicate with each other and on the larger scale, which areas of the brain are used for sensory perception, action and cognition. However, we know less about the translation of neural activity into behavior, such as turning thought into muscle movement.

Supercomputer software has helped by simulating the exchange of signals between neurons, but even the best software run on the fastest supercomputers to date can only simulate 1% of the human brain.

“It is presently unclear which computer architecture is best suited to study whole-brain networks efficiently. The European Human Brain Project and Jülich Research Centre have performed extensive research to identify the best strategy for this highly complex problem. Today’s supercomputers require several minutes to simulate one second of real time, so studies on processes like learning, which take hours and days in real time are currently out of reach.” explains Professor Markus Diesmann, co-author, head of the Computational and Systems Neuroscience department at the Jülich Research Centre.

He continues, “There is a huge gap between the energy consumption of the brain and today’s supercomputers. Neuromorphic (brain-inspired) computing allows us to investigate how close we can get to the energy efficiency of the brain using electronics.”

Developed over the past 15 years and based on the structure and function of the human brain, SpiNNaker — part of the Neuromorphic Computing Platform of the Human Brain Project — is a custom-built computer composed of half a million of simple computing elements controlled by its own software. The researchers compared the accuracy, speed and energy efficiency of SpiNNaker with that of NEST–a specialist supercomputer software currently in use for brain neuron-signaling research.

“The simulations run on NEST and SpiNNaker showed very similar results,” reports Steve Furber, co-author and Professor of Computer Engineering at the University of Manchester, UK. “This is the first time such a detailed simulation of the cortex has been run on SpiNNaker, or on any neuromorphic platform. SpiNNaker comprises 600 circuit boards incorporating over 500,000 small processors in total. The simulation described in this study used just six boards–1% of the total capability of the machine. The findings from our research will improve the software to reduce this to a single board.”

Van Albada shares her future aspirations for SpiNNaker, “We hope for increasingly large real-time simulations with these neuromorphic computing systems. In the Human Brain Project, we already work with neuroroboticists who hope to use them for robotic control.”

Before getting to the link and citation for the paper, here’s a description of SpiNNaker’s hardware from the ‘Spiking neural netowrk’ Wikipedia entry, Note: Links have been removed,

Neurogrid, built at Stanford University, is a board that can simulate spiking neural networks directly in hardware. SpiNNaker (Spiking Neural Network Architecture) [emphasis mine], designed at the University of Manchester, uses ARM processors as the building blocks of a massively parallel computing platform based on a six-layer thalamocortical model.[5]

Now for the link and citation,

Performance Comparison of the Digital Neuromorphic Hardware SpiNNaker and the Neural Network Simulation Software NEST for a Full-Scale Cortical Microcircuit Model by
Sacha J. van Albada, Andrew G. Rowley, Johanna Senk, Michael Hopkins, Maximilian Schmidt, Alan B. Stokes, David R. Lester, Markus Diesmann, and Steve B. Furber. Neurosci. 12:291. doi: 10.3389/fnins.2018.00291 Published: 23 May 2018

As noted earlier, this is an open access paper.