This work comes from Dartmouth College, an educational institution based on the US east coast in the state of New Hampshire. I hardly ever stumble across research from Dartmouth and I assume that’s because they usually focus their interests in areas that are not of direct interest to me,
For a change, we have a point of connection (harvesting biokinetic energy) according to a February 4, 2019 news item on ScienceDaily,
The heart’s motion is so powerful that it can recharge devices that save our lives, according to new research from Dartmouth College.
Using a dime-sized invention developed by engineers at the Thayer School of Engineering at Dartmouth, the kinetic energy of the heart can be converted into electricity to power a wide-range of implantable devices, according to the study funded by the National Institutes of Health.
Millions of people rely on pacemakers, defibrillators and other live-saving implantable devices powered by batteries that need to be replaced every five to 10 years. Those replacements require surgery which can be costly and create the possibility of complications and infections.
“We’re trying to solve the ultimate problem for any implantable biomedical device,” says Dartmouth engineering professor John X.J. Zhang, a lead researcher on the study his team completed alongside clinicians at the University of Texas in San Antonio. “How do you create an effective energy source so the device will do its job during the entire life span of the patient, without the need for surgery to replace the battery?”
“Of equal importance is that the device not interfere with the body’s function,” adds Dartmouth research associate Lin Dong, first author on the paper. “We knew it had to be biocompatible, lightweight, flexible, and low profile, so it not only fits into the current pacemaker structure but is also scalable for future multi-functionality.”
The team’s work proposes modifying pacemakers to harness the kinetic energy of the lead wire that’s attached to the heart, converting it into electricity to continually charge the batteries. The added material is a type of thin polymer piezoelectric film called “PVDF” and, when designed with porous structures — either an array of small buckle beams or a flexible cantilever — it can convert even small mechanical motion to electricity. An added benefit: the same modules could potentially be used as sensors to enable data collection for real-time monitoring of patients.
The results of the three-year study, completed by Dartmouth’s engineering researchers along with clinicians at UT Health San Antonio, were just published in the cover story for Advanced Materials Technologies.
The two remaining years of NIH funding plus time to finish the pre-clinical process and obtain regulatory approval puts a self-charging pacemaker approximately five years out from commercialization, according to Zhang
“We’ve completed the first round of animal studies with great results which will be published soon,” says Zhang. “There is already a lot of expressed interest from the major medical technology companies, and Andrew Closson, one of the study’s authors working with Lin Dong and an engineering PhD Innovation Program student at Dartmouth, is learning the business and technology transfer skills to be a cohort in moving forward with the entrepreneurial phase of this effort.”
Other key collaborators on the study include Dartmouth engineering professor Zi Chen, an expert on thin structure mechanics, and Dr. Marc Feldman, professor and clinical cardiologist at UT [University of Texas] Health San Antonio.
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.
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.
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,
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.
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.
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).
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.”
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,
This news comes out of the University of Maryland and the discovery could led to nanoparticles that have never before been imagined. From a March 29, 2018 news item on ScienceDaily,
Making a giant leap in the ‘tiny’ field of nanoscience, a multi-institutional team of researchers is the first to create nanoscale particles composed of up to eight distinct elements generally known to be immiscible, or incapable of being mixed or blended together. The blending of multiple, unmixable elements into a unified, homogenous nanostructure, called a high entropy alloy nanoparticle, greatly expands the landscape of nanomaterials — and what we can do with them.
This research makes a significant advance on previous efforts that have typically produced nanoparticles limited to only three different elements and to structures that do not mix evenly. Essentially, it is extremely difficult to squeeze and blend different elements into individual particles at the nanoscale. The team, which includes lead researchers at University of Maryland, College Park (UMD)’s A. James Clark School of Engineering, published a peer-reviewed paper based on the research featured on the March 30  cover of Science.
“Imagine the elements that combine to make nanoparticles as Lego building blocks. If you have only one to three colors and sizes, then you are limited by what combinations you can use and what structures you can assemble,” explains Liangbing Hu, associate professor of materials science and engineering at UMD and one of the corresponding authors of the paper. “What our team has done is essentially enlarged the toy chest in nanoparticle synthesis; now, we are able to build nanomaterials with nearly all metallic and semiconductor elements.”
The researchers say this advance in nanoscience opens vast opportunities for a wide range of applications that includes catalysis (the acceleration of a chemical reaction by a catalyst), energy storage (batteries or supercapacitors), and bio/plasmonic imaging, among others.
To create the high entropy alloy nanoparticles, the researchers employed a two-step method of flash heating followed by flash cooling. Metallic elements such as platinum, nickel, iron, cobalt, gold, copper, and others were exposed to a rapid thermal shock of approximately 3,000 degrees Fahrenheit, or about half the temperature of the sun, for 0.055 seconds. The extremely high temperature resulted in uniform mixtures of the multiple elements. The subsequent rapid cooling (more than 100,000 degrees Fahrenheit per second) stabilized the newly mixed elements into the uniform nanomaterial.
“Our method is simple, but one that nobody else has applied to the creation of nanoparticles. By using a physical science approach, rather than a traditional chemistry approach, we have achieved something unprecedented,” says Yonggang Yao, a Ph.D. student at UMD and one of the lead authors of the paper.
To demonstrate one potential use of the nanoparticles, the research team used them as advanced catalysts for ammonia oxidation, which is a key step in the production of nitric acid (a liquid acid that is used in the production of ammonium nitrate for fertilizers, making plastics, and in the manufacturing of dyes). They were able to achieve 100 percent oxidation of ammonia and 99 percent selectivity toward desired products with the high entropy alloy nanoparticles, proving their ability as highly efficient catalysts.
Yao says another potential use of the nanoparticles as catalysts could be the generation of chemicals or fuels from carbon dioxide.
“The potential applications for high entropy alloy nanoparticles are not limited to the field of catalysis. With cross-discipline curiosity, the demonstrated applications of these particles will become even more widespread,” says Steven D. Lacey, a Ph.D. student at UMD and also one of the lead authors of the paper.
This research was performed through a multi-institutional collaboration of Prof. Liangbing Hu’s group at the University of Maryland, College Park; Prof. Reza Shahbazian-Yassar’s group at University of Illinois at Chicago; Prof. Ju Li’s group at the Massachusetts Institute of Technology; Prof. Chao Wang’s group at Johns Hopkins University; and Prof. Michael Zachariah’s group at the University of Maryland, College Park.
What outside experts are saying about this research:
“This is quite amazing; Dr. Hu creatively came up with this powerful technique, carbo-thermal shock synthesis, to produce high entropy alloys of up to eight different elements in a single nanoparticle. This is indeed unthinkable for bulk materials synthesis. This is yet another beautiful example of nanoscience!,” says Peidong Yang, the S.K. and Angela Chan Distinguished Professor of Energy and professor of chemistry at the University of California, Berkeley and member of the American Academy of Arts and Sciences.
“This discovery opens many new directions. There are simulation opportunities to understand the electronic structure of the various compositions and phases that are important for the next generation of catalyst design. Also, finding correlations among synthesis routes, composition, and phase structure and performance enables a paradigm shift toward guided synthesis,” says George Crabtree, Argonne Distinguished Fellow and director of the Joint Center for Energy Storage Research at Argonne National Laboratory.
More from the research coauthors:
“Understanding the atomic order and crystalline structure in these multi-element nanoparticles reveals how the synthesis can be tuned to optimize their performance. It would be quite interesting to further explore the underlying atomistic mechanisms of the nucleation and growth of high entropy alloy nanoparticle,” says Reza Shahbazian-Yassar, associate professor at the University of Illinois at Chicago and a corresponding author of the paper.
“Carbon metabolism drives ‘living’ metal catalysts that frequently move around, split, or merge, resulting in a nanoparticle size distribution that’s far from the ordinary, and highly tunable,” says Ju Li, professor at the Massachusetts Institute of Technology and a corresponding author of the paper.
“This method enables new combinations of metals that do not exist in nature and do not otherwise go together. It enables robust tuning of the composition of catalytic materials to optimize the activity, selectivity, and stability, and the application will be very broad in energy conversions and chemical transformations,” says Chao Wang, assistant professor of chemical and biomolecular engineering at Johns Hopkins University and one of the study’s authors.
Here’s a link to and a citation for the paper,
Carbothermal shock synthesis of high-entropy-alloy nanoparticles by Yonggang Yao, Zhennan Huang, Pengfei Xie, Steven D. Lacey, Rohit Jiji Jacob, Hua Xie, Fengjuan Chen, Anmin Nie, Tiancheng Pu, Miles Rehwoldt, Daiwei Yu, Michael R. Zachariah, Chao Wang, Reza Shahbazian-Yassar, Ju Li, Liangbing Hu. Science 30 Mar 2018: Vol. 359, Issue 6383, pp. 1489-1494 DOI: 10.1126/science.aan5412
It takes a lot more imagination than I have to describe the object on the right as resembling the candy cane on the left, assuming that’s what was intended when it was used to illustrate the university’s press release. I like being pushed to see resemblances to things that are not immediately apparent to me. This may never look like a candy cane to me but I appreciate that someone finds it to be so. An August 16, 2017 news item on ScienceDaily announces the ‘candy cane’ supercapacitor,
Supercapacitors promise recharging of phones and other devices in seconds and minutes as opposed to hours for batteries. But current technologies are not usually flexible, have insufficient capacities, and for many their performance quickly degrades with charging cycles.
Researchers at Queen Mary University of London (QMUL) and the University of Cambridge have found a way to improve all three problems in one stroke.
Their prototyped polymer electrode, which resembles a candy cane usually hung on a Christmas tree, achieves energy storage close to the theoretical limit, but also demonstrates flexibility and resilience to charge/discharge cycling.
The technique could be applied to many types of materials for supercapacitors and enable fast charging of mobile phones, smart clothes and implantable devices.
Pseudocapacitance is a property of polymer and composite supercapacitors that allows ions to enter inside the material and thus pack much more charge than carbon ones that mostly store the charge as concentrated ions (in the so-called double layer) near the surface.
The problem with polymer supercapacitors, however, is that the ions necessary for these chemical reactions can only access the top few nanometers below the material surface, leaving the rest of the electrode as dead weight. Growing polymers as nano-structures is one way to increase the amount of accessible material near the surface, but this can be expensive, hard to scale up, and often results in poor mechanical stability.
The researchers, however, have developed a way to interweave nanostructures within a bulk material, thereby achieving the benefits of conventional nanostructuring without using complex synthesis methods or sacrificing material toughness.
Project leader, Stoyan Smoukov, explained: “Our supercapacitors can store a lot of charge very quickly, because the thin active material (the conductive polymer) is always in contact with a second polymer which contains ions, just like the red thin regions of a candy cane are always in close proximity to the white parts. But this is on a much smaller scale.
“This interpenetrating structure enables the material to bend more easily, as well as swell and shrink without cracking, leading to greater longevity. This one method is like killing not just two, but three birds with one stone.”
The Smoukov group had previously pioneered a combinatorial route to multifunctionality using interpenetrating polymer networks (IPN) in which each component would have its own function, rather than using trial-and-error chemistry to fit all functions in one molecule.
This time they applied the method to energy storage, specifically supercapacitors, because of the known problem of poor material utilization deep beneath the electrode surface.
This interpenetration technique drastically increases the material’s surface area, or more accurately the interfacial area between the different polymer components.
Interpenetration also happens to solve two other major problems in supercapacitors. It brings flexibility and toughness because the interfaces stop growth of any cracks that may form in the material. It also allows the thin regions to swell and shrink repeatedly without developing large stresses, so they are electrochemically resistant and maintain their performance over many charging cycles.
The researchers are currently rationally designing and evaluating a range of materials that can be adapted into the interpenetrating polymer system for even better supercapacitors.
In an upcoming review, accepted for publication in the journal Sustainable Energy and Fuels, they overview the different techniques people have used to improve the multiple parameters required for novel supercapacitors.
Such devices could be made in soft and flexible freestanding films, which could power electronics embedded in smart clothing, wearable and implantable devices, and soft robotics. The developers hope to make their contribution to provide ubiquitous power for the emerging Internet of Things (IoT) devices, which is still a significant challenge ahead.
A Jan. 16, 2017 news item on ScienceDaily describes what lengths researchers at Stanford University (US) will go to in pursuit of their goals,
In a lab 18 feet below the Engineering Quad of Stanford University, researchers in the Dionne lab camped out with one of the most advanced microscopes in the world to capture an unimaginably small reaction.
The lab members conducted arduous experiments — sometimes requiring a continuous 30 hours of work — to capture real-time, dynamic visualizations of atoms that could someday help our phone batteries last longer and our electric vehicles go farther on a single charge.
Toiling underground in the tunneled labs, they recorded atoms moving in and out of nanoparticles less than 100 nanometers in size, with a resolution approaching 1 nanometer.
“The ability to directly visualize reactions in real time with such high resolution will allow us to explore many unanswered questions in the chemical and physical sciences,” said Jen Dionne, associate professor of materials science and engineering at Stanford and senior author of the paper detailing this work, published Jan. 16  in Nature Communications. “While the experiments are not easy, they would not be possible without the remarkable advances in electron microscopy from the past decade.”
Their experiments focused on hydrogen moving into palladium, a class of reactions known as an intercalation-driven phase transition. This reaction is physically analogous to how ions flow through a battery or fuel cell during charging and discharging. Observing this process in real time provides insight into why nanoparticles make better electrodes than bulk materials and fits into Dionne’s larger interest in energy storage devices that can charge faster, hold more energy and stave off permanent failure.
Technical complexity and ghosts
For these experiments, the Dionne lab created palladium nanocubes, a form of nanoparticle, that ranged in size from about 15 to 80 nanometers, and then placed them in a hydrogen gas environment within an electron microscope. The researchers knew that hydrogen would change both the dimensions of the lattice and the electronic properties of the nanoparticle. They thought that, with the appropriate microscope lens and aperture configuration, techniques called scanning transmission electron microscopy and electron energy loss spectroscopy might show hydrogen uptake in real time.
After months of trial and error, the results were extremely detailed, real-time videos of the changes in the particle as hydrogen was introduced. The entire process was so complicated and novel that the first time it worked, the lab didn’t even have the video software running, leading them to capture their first movie success on a smartphone.
Following these videos, they examined the nanocubes during intermediate stages of hydrogenation using a second technique in the microscope, called dark-field imaging, which relies on scattered electrons. In order to pause the hydrogenation process, the researchers plunged the nanocubes into an ice bath of liquid nitrogen mid-reaction, dropping their temperature to 100 degrees Kelvin (-280 F). These dark-field images served as a way to check that the application of the electron beam hadn’t influenced the previous observations and allowed the researchers to see detailed structural changes during the reaction.
“With the average experiment spanning about 24 hours at this low temperature, we faced many instrument problems and called Ai Leen Koh [co-author and research scientist at Stanford’s Nano Shared Facilities] at the weirdest hours of the night,” recalled Fariah Hayee, co-lead author of the study and graduate student in the Dionne lab. “We even encountered a ‘ghost-of-the-joystick problem,’ where the joystick seemed to move the sample uncontrollably for some time.”
While most electron microscopes operate with the specimen held in a vacuum, the microscope used for this research has the advanced ability to allow the researchers to introduce liquids or gases to their specimen.
“We benefit tremendously from having access to one of the best microscope facilities in the world,” said Tarun Narayan, co-lead author of this study and recent doctoral graduate from the Dionne lab. “Without these specific tools, we wouldn’t be able to introduce hydrogen gas or cool down our samples enough to see these processes take place.”
Pushing out imperfections
Aside from being a widely applicable proof of concept for this suite of visualization techniques, watching the atoms move provides greater validation for the high hopes many scientists have for nanoparticle energy storage technologies.
The researchers saw the atoms move in through the corners of the nanocube and observed the formation of various imperfections within the particle as hydrogen moved within it. This sounds like an argument against the promise of nanoparticles but that’s because it’s not the whole story.
“The nanoparticle has the ability to self-heal,” said Dionne. “When you first introduce hydrogen, the particle deforms and loses its perfect crystallinity. But once the particle has absorbed as much hydrogen as it can, it transforms itself back to a perfect crystal again.”
The researchers describe this as imperfections being “pushed out” of the nanoparticle. This ability of the nanocube to self-heal makes it more durable, a key property needed for energy storage materials that can sustain many charge and discharge cycles.
Looking toward the future
As the efficiency of renewable energy generation increases, the need for higher quality energy storage is more pressing than ever. It’s likely that the future of storage will rely on new chemistries and the findings of this research, including the microscopy techniques the researchers refined along the way, will apply to nearly any solution in those categories.
For its part, the Dionne lab has many directions it can go from here. The team could look at a variety of material compositions, or compare how the sizes and shapes of nanoparticles affect the way they work, and, soon, take advantage of new upgrades to their microscope to study light-driven reactions. At present, Hayee has moved on to experimenting with nanorods, which have more surface area for the ions to move through, promising potentially even faster kinetics.
Scientists from Duke University aren’t exactly ‘brewing’ or ‘cooking up’ the inks but they do come close according to a Jan. 3, 2017 news item on ScienceDaily,
By suspending tiny metal nanoparticles in liquids, Duke University scientists are brewing up conductive ink-jet printer “inks” to print inexpensive, customizable circuit patterns on just about any surface.
Printed electronics, which are already being used on a wide scale in devices such as the anti-theft radio frequency identification (RFID) tags you might find on the back of new DVDs, currently have one major drawback: for the circuits to work, they first have to be heated to melt all the nanoparticles together into a single conductive wire, making it impossible to print circuits on inexpensive plastics or paper.
A new study by Duke researchers shows that tweaking the shape of the nanoparticles in the ink might just eliminate the need for heat.
By comparing the conductivity of films made from different shapes of silver nanostructures, the researchers found that electrons zip through films made of silver nanowires much easier than films made from other shapes, like nanospheres or microflakes. In fact, electrons flowed so easily through the nanowire films that they could function in printed circuits without the need to melt them all together.
“The nanowires had a 4,000 times higher conductivity than the more commonly used silver nanoparticles that you would find in printed antennas for RFID tags,” said Benjamin Wiley, assistant professor of chemistry at Duke. “So if you use nanowires, then you don’t have to heat the printed circuits up to such high temperature and you can use cheaper plastics or paper.”
“There is really nothing else I can think of besides these silver nanowires that you can just print and it’s simply conductive, without any post-processing,” Wiley added.
These types of printed electronics could have applications far beyond smart packaging; researchers envision using the technology to make solar cells, printed displays, LEDS, touchscreens, amplifiers, batteries and even some implantable bio-electronic devices. The results appeared online Dec. 16  in ACS Applied Materials and Interfaces.
Silver has become a go-to material for making printed electronics, Wiley said, and a number of studies have recently appeared measuring the conductivity of films with different shapes of silver nanostructures. However, experimental variations make direct comparisons between the shapes difficult, and few reports have linked the conductivity of the films to the total mass of silver used, an important factor when working with a costly material.
“We wanted to eliminate any extra materials from the inks and simply hone in on the amount of silver in the films and the contacts between the nanostructures as the only source of variability,” said Ian Stewart, a recent graduate student in Wiley’s lab and first author on the ACS paper.
Stewart used known recipes to cook up silver nanostructures with different shapes, including nanoparticles, microflakes, and short and long nanowires, and mixed these nanostructures with distilled water to make simple “inks.” He then invented a quick and easy way to make thin films using equipment available in just about any lab — glass slides and double-sided tape.
“We used a hole punch to cut out wells from double-sided tape and stuck these to glass slides,” Stewart said. By adding a precise volume of ink into each tape “well” and then heating the wells — either to relatively low temperature to simply evaporate the water or to higher temperatures to begin melting the structures together — he created a variety of films to test.
The team say they weren’t surprised that the long nanowire films had the highest conductivity. Electrons usually flow easily through individual nanostructures but get stuck when they have to jump from one structure to the next, Wiley explained, and long nanowires greatly reduce the number of times the electrons have to make this “jump”.
But they were surprised at just how drastic the change was. “The resistivity of the long silver nanowire films is several orders of magnitude lower than silver nanoparticles and only 10 times greater than pure silver,” Stewart said.
The team is now experimenting with using aerosol jets to print silver nanowire inks in usable circuits. Wiley says they also want to explore whether silver-coated copper nanowires, which are significantly cheaper to produce than pure silver nanowires, will give the same effect.
This paper is behind a paywall but there is an image of the silver nanowires, which is not exactly compensation but is interesting,
Caption: Duke University chemists have found that silver nanowire films like these conduct electricity well enough to form functioning circuits without applying high temperatures, enabling printable electronics on heat-sensitive materials like paper or plastic. Credit: Ian Stewart and Benjamin Wiley
Scientists are researching devices other than batteries for wind and solar energy storage according to an Oct. 27, 2016 news item on Nanowerk,
Saving up excess solar and wind energy for times when the sun is down or the air is still requires a storage device. Batteries get the most attention as a promising solution although pumped hydroelectric storage is currently used most often. Now researchers reporting in ACS’ Journal of Physical Chemistry C are advancing another potential approach using sugar alcohols — an abundant waste product of the food industry — mixed with carbon nanotubes.
Electricity generation from renewables has grown steadily over recent years, and the U.S. Energy Information Administration (EIA) expects this rise to continue. To keep up with this expansion, use of battery and flywheel energy storage has increased in the past five years, according to the EIA. These technologies take advantage of chemical and mechanical energy. But storing energy as heat is another feasible option. Some scientists have been exploring sugar alcohols as a possible material for making thermal storage work, but this direction has some limitations. Huaichen Zhang, Silvia V. Nedea and colleagues wanted to investigate how mixing carbon nanotubes with sugar alcohols might affect their energy storage properties.
The researchers analyzed what happened when carbon nanotubes of varying sizes were mixed with two types of sugar alcohols — erythritol and xylitol, both naturally occurring compounds in foods. Their findings showed that with one exception, heat transfer within a mixture decreased as the nanotube diameter decreased. They also found that in general, higher density combinations led to better heat transfer. The researchers say these new insights could assist in the future design of sugar alcohol-based energy storage systems.
Vitamin-inspired batteries from Harvard University? According to a July 18, 2016 news item on ScienceDaily that’s exactly the case,
Harvard researchers have identified a whole new class of high-performing organic molecules, inspired by vitamin B2, that can safely store electricity from intermittent energy sources like solar and wind power in large batteries.
The development builds on previous work in which the team developed a high-capacity flow battery that stored energy in organic molecules called quinones and a food additive called ferrocyanide. That advance was a game-changer, delivering the first high-performance, non-flammable, non-toxic, non-corrosive, and low-cost chemicals that could enable large-scale, inexpensive electricity storage.
While the versatile quinones show great promise for flow batteries, Harvard researchers continued to explore other organic molecules in pursuit of even better performance. But finding that same versatility in other organic systems has been challenging.
“Now, after considering about a million different quinones, we have developed a new class of battery electrolyte material that expands the possibilities of what we can do,” said Kaixiang Lin, a Ph.D. student at Harvard and first author of the paper. “Its simple synthesis means it should be manufacturable on a large scale at a very low cost, which is an important goal of this project.”
Flow batteries store energy in solutions in external tanks — the bigger the tanks, the more energy they store. In 2014, Michael J. Aziz, the Gene and Tracy Sykes Professor of Materials and Energy Technologies at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), Roy Gordon, the Thomas Dudley Cabot Professor of Chemistry and Professor of Materials Science, Alán Aspuru-Guzik, Professor of Chemistry and their team at Harvard replaced metal ions used as conventional battery electrolyte materials in acidic electrolytes with quinones, molecules that store energy in plants and animals. In 2015, they developed a quinone that could work in alkaline solutions alongside a common food additive.
In this most recent research, the team found inspiration in vitamin B2, which helps to store energy from food in the body. The key difference between B2 and quinones is that nitrogen atoms, instead of oxygen atoms, are involved in picking up and giving off electrons.
“With only a couple of tweaks to the original B2 molecule, this new group of molecules becomes a good candidate for alkaline flow batteries,” said Aziz.
“They have high stability and solubility and provide high battery voltage and storage capacity. Because vitamins are remarkably easy to make, this molecule could be manufactured on a large scale at a very low cost.”
“We designed these molecules to suit the needs of our battery, but really it was nature that hinted at this way to store energy,” said Gordon, co-senior author of the paper. “Nature came up with similar molecules that are very important in storing energy in our bodies.”
The team will continue to explore quinones, as well as this new universe of molecules, in pursuit of a high-performing, long-lasting and inexpensive flow battery.
The Materials Project, a Google-like database of material properties aimed at accelerating innovation, has released an enormous trove of data to the public, giving scientists working on fuel cells, photovoltaics, thermoelectrics, and a host of other advanced materials a powerful tool to explore new research avenues. But it has become a particularly important resource for researchers working on batteries. Co-founded and directed by Lawrence Berkeley National Laboratory (Berkeley Lab) scientist Kristin Persson, the Materials Project uses supercomputers to calculate the properties of materials based on first-principles quantum-mechanical frameworks. It was launched in 2011 by the U.S. Department of Energy’s (DOE) Office of Science.
The idea behind the Materials Project is that it can save researchers time by predicting material properties without needing to synthesize the materials first in the lab. It can also suggest new candidate materials that experimentalists had not previously dreamed up. With a user-friendly web interface, users can look up the calculated properties, such as voltage, capacity, band gap, and density, for tens of thousands of materials.
Two sets of data were released last month: nearly 1,500 compounds investigated for multivalent intercalation electrodes and more than 21,000 organic molecules relevant for liquid electrolytes as well as a host of other research applications. Batteries with multivalent cathodes (which have multiple electrons per mobile ion available for charge transfer) are promising candidates for reducing cost and achieving higher energy density than that available with current lithium-ion technology.
The sheer volume and scope of the data is unprecedented, said Persson, who is also a professor in UC Berkeley’s Department of Materials Science and Engineering. “As far as the multivalent cathodes, there’s nothing similar in the world that exists,” she said. “To give you an idea, experimentalists are usually able to focus on one of these materials at a time. Using calculations, we’ve added data on 1,500 different compositions.”
While other research groups have made their data publicly available, what makes the Materials Project so useful are the online tools to search all that data. The recent release includes two new web apps—the Molecules Explorer and the Redox Flow Battery Dashboard—plus an add-on to the Battery Explorer web app enabling researchers to work with other ions in addition to lithium.
“Not only do we give the data freely, we also give algorithms and software to interpret or search over the data,” Persson said.
The Redox Flow Battery app gives scientific parameters as well as techno-economic ones, so battery designers can quickly rule out a molecule that might work well but be prohibitively expensive. The Molecules Explorer app will be useful to researchers far beyond the battery community.
“For multivalent batteries it’s so hard to get good experimental data,” Persson said. “The calculations provide rich and robust benchmarks to assess whether the experiments are actually measuring a valid intercalation process or a side reaction, which is particularly difficult for multivalent energy technology because there are so many problems with testing these batteries.”
Here’s a screen capture from the Battery Explorer app,
The Materials Project’s Battery Explorer app now allows researchers to work with other ions in addition to lithium. Courtesy: The Materials Project
The news release goes on to describe a new discovery made possible by The Materials Project (Note: A link has been removed),
Together with Persson, Berkeley Lab scientist Gerbrand Ceder, postdoctoral associate Miao Liu, and MIT graduate student Ziqin Rong, the Materials Project team investigated some of the more promising materials in detail for high multivalent ion mobility, which is the most difficult property to achieve in these cathodes. This led the team to materials known as thiospinels. One of these thiospinels has double the capacity of the currently known multivalent cathodes and was recently synthesized and tested in the lab by JCESR researcher Linda Nazar of the University of Waterloo, Canada.
“These materials may not work well the first time you make them,” Persson said. “You have to be persistent; for example you may have to make the material very phase pure or smaller than a particular particle size and you have to test them under very controlled conditions. There are people who have actually tried this material before and discarded it because they thought it didn’t work particularly well. The power of the computations and the design metrics we have uncovered with their help is that it gives us the confidence to keep trying.”
The researchers were able to double the energy capacity of what had previously been achieved for this kind of multivalent battery. The study has been published in the journal Energy & Environmental Science in an article titled, “A High Capacity Thiospinel Cathode for Mg Batteries.”
“The new multivalent battery works really well,” Persson said. “It’s a significant advance and an excellent proof-of-concept for computational predictions as a valuable new tool for battery research.”
Here’s a link to and a citation for the paper,
A high capacity thiospinel cathode for Mg batteries by Xiaoqi Sun, Patrick Bonnick, Victor Duffort, Miao Liu, Ziqin Rong, Kristin A. Persson, Gerbrand Ceder and Linda F. Nazar. Energy Environ. Sci., 2016, Advance Article DOI: 10.1039/C6EE00724D First published online 24 May 2016
This paper seems to be behind a paywall.
Getting back to the news release, there’s more about The Materials Project in relationship to its membership,
The Materials Project has attracted more than 20,000 users since launching five years ago. Every day about 20 new users register and 300 to 400 people log in to do research.
One of those users is Dane Morgan, a professor of engineering at the University of Wisconsin-Madison who develops new materials for a wide range of applications, including highly active catalysts for fuel cells, stable low-work function electron emitter cathodes for high-powered microwave devices, and efficient, inexpensive, and environmentally safe solar materials.
“The Materials Project has enabled some of the most exciting research in my group,” said Morgan, who also serves on the Materials Project’s advisory board. “By providing easy access to a huge database, as well as tools to process that data for thermodynamic predictions, the Materials Project has enabled my group to rapidly take on materials design projects that would have been prohibitive just a few years ago.”
More materials are being calculated and added to the database every day. In two years, Persson expects another trove of data to be released to the public.
“This is the way to reach a significant part of the research community, to reach students while they’re still learning material science,” she said. “It’s a teaching tool. It’s a science tool. It’s unprecedented.”
Supercomputing clusters at the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility hosted at Berkeley Lab, provide the infrastructure for the Materials Project.
Funding for the Materials Project is provided by the Office of Science (US Department of Energy], including support through JCESR [Joint Center for Energy Storage Research].