Tag Archives: US Defense Advanced Research Projects Agency

Metamaterial could supply air conditioning with zero energy consumption

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This is exciting provided they can scale up the metamaterial for industrial use. A Feb. 9, 2017 news item on Nanowerk announces a new metamaterial that could change air conditioning  from the University of Colorado at Boulder (Note: A link has been removed),

A team of University of Colorado Boulder engineers has developed a scalable manufactured metamaterial — an engineered material with extraordinary properties not found in nature — to act as a kind of air conditioning system for structures. It has the ability to cool objects even under direct sunlight with zero energy and water consumption.

When applied to a surface, the metamaterial film cools the object underneath by efficiently reflecting incoming solar energy back into space while simultaneously allowing the surface to shed its own heat in the form of infrared thermal radiation.

The new material, which is described today in the journal Science (“Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling”), could provide an eco-friendly means of supplementary cooling for thermoelectric power plants, which currently require large amounts of water and electricity to maintain the operating temperatures of their machinery.

A Feb. 9, 2017 University of Colorado at Boulder news release (also on EurekAlert), which originated the news item, expands on the theme (Note: Links have been removed),

The researchers’ glass-polymer hybrid material measures just 50 micrometers thick — slightly thicker than the aluminum foil found in a kitchen — and can be manufactured economically on rolls, making it a potentially viable large-scale technology for both residential and commercial applications.

“We feel that this low-cost manufacturing process will be transformative for real-world applications of this radiative cooling technology,” said Xiaobo Yin, co-director of the research and an assistant professor who holds dual appointments in CU Boulder’s Department of Mechanical Engineering and the Materials Science and Engineering Program. Yin received DARPA’s [US Defense Advanced Research Projects Agency] Young Faculty Award in 2015.

The material takes advantage of passive radiative cooling, the process by which objects naturally shed heat in the form of infrared radiation, without consuming energy. Thermal radiation provides some natural nighttime cooling and is used for residential cooling in some areas, but daytime cooling has historically been more of a challenge. For a structure exposed to sunlight, even a small amount of directly-absorbed solar energy is enough to negate passive radiation.

The challenge for the CU Boulder researchers, then, was to create a material that could provide a one-two punch: reflect any incoming solar rays back into the atmosphere while still providing a means of escape for infrared radiation. To solve this, the researchers embedded visibly-scattering but infrared-radiant glass microspheres into a polymer film. They then added a thin silver coating underneath in order to achieve maximum spectral reflectance.

“Both the glass-polymer metamaterial formation and the silver coating are manufactured at scale on roll-to-roll processes,” added Ronggui Yang, also a professor of mechanical engineering and a Fellow of the American Society of Mechanical Engineers.

“Just 10 to 20 square meters of this material on the rooftop could nicely cool down a single-family house in summer,” said Gang Tan, an associate professor in the University of Wyoming’s Department of Civil and Architectural Engineering and a co-author of the paper.

In addition to being useful for cooling of buildings and power plants, the material could also help improve the efficiency and lifetime of solar panels. In direct sunlight, panels can overheat to temperatures that hamper their ability to convert solar rays into electricity.

“Just by applying this material to the surface of a solar panel, we can cool the panel and recover an additional one to two percent of solar efficiency,” said Yin. “That makes a big difference at scale.”

The engineers have applied for a patent for the technology and are working with CU Boulder’s Technology Transfer Office to explore potential commercial applications. They plan to create a 200-square-meter “cooling farm” prototype in Boulder in 2017.

The invention is the result of a $3 million grant awarded in 2015 to Yang, Yin and Tang by the Energy Department’s Advanced Research Projects Agency-Energy (ARPA-E).

“The key advantage of this technology is that it works 24/7 with no electricity or water usage,” said Yang “We’re excited about the opportunity to explore potential uses in the power industry, aerospace, agriculture and more.”

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

Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling by Yao Zhai, Yaoguang Ma, Sabrina N. David, Dongliang Zhao, Runnan Lou, Gang Tan, Ronggui Yang, Xiaobo Yin. Science  09 Feb 2017: DOI: 10.1126/science.aai7899

This paper is behind a paywall.

Members of the research team show off the metamaterial (?) Courtesy: University of Colorado at Boulder

I added the caption to this image, which was on the University of Colorado at Boulder’s home page where it accompanied the news release headline on the rotating banner.

Powering up your graphene implants so you don’t get fried in the process

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A Sept. 23, 2016 news item on phys.org describes a way of making graphene-based medical implants safer,

In the future, our health may be monitored and maintained by tiny sensors and drug dispensers, deployed within the body and made from graphene—one of the strongest, lightest materials in the world. Graphene is composed of a single sheet of carbon atoms, linked together like razor-thin chicken wire, and its properties may be tuned in countless ways, making it a versatile material for tiny, next-generation implants.

But graphene is incredibly stiff, whereas biological tissue is soft. Because of this, any power applied to operate a graphene implant could precipitously heat up and fry surrounding cells.

Now, engineers from MIT [Massachusetts Institute of Technology] and Tsinghua University in Beijing have precisely simulated how electrical power may generate heat between a single layer of graphene and a simple cell membrane. While direct contact between the two layers inevitably overheats and kills the cell, the researchers found they could prevent this effect with a very thin, in-between layer of water.

A Sept. 23, 2016 MIT news release by Emily Chu, which originated the news item, provides more technical details,

By tuning the thickness of this intermediate water layer, the researchers could carefully control the amount of heat transferred between graphene and biological tissue. They also identified the critical power to apply to the graphene layer, without frying the cell membrane. …

Co-author Zhao Qin, a research scientist in MIT’s Department of Civil and Environmental Engineering (CEE), says the team’s simulations may help guide the development of graphene implants and their optimal power requirements.

“We’ve provided a lot of insight, like what’s the critical power we can accept that will not fry the cell,” Qin says. “But sometimes we might want to intentionally increase the temperature, because for some biomedical applications, we want to kill cells like cancer cells. This work can also be used as guidance [for those efforts.]”

…

Sandwich model

Typically, heat travels between two materials via vibrations in each material’s atoms. These atoms are always vibrating, at frequencies that depend on the properties of their materials. As a surface heats up, its atoms vibrate even more, causing collisions with other atoms and transferring heat in the process.

The researchers sought to accurately characterize the way heat travels, at the level of individual atoms, between graphene and biological tissue. To do this, they considered the simplest interface, comprising a small, 500-nanometer-square sheet of graphene and a simple cell membrane, separated by a thin layer of water.

“In the body, water is everywhere, and the outer surface of membranes will always like to interact with water, so you cannot totally remove it,” Qin says. “So we came up with a sandwich model for graphene, water, and membrane, that is a crystal clear system for seeing the thermal conductance between these two materials.”

Qin’s colleagues at Tsinghua University had previously developed a model to precisely simulate the interactions between atoms in graphene and water, using density functional theory — a computational modeling technique that considers the structure of an atom’s electrons in determining how that atom will interact with other atoms.

However, to apply this modeling technique to the group’s sandwich model, which comprised about half a million atoms, would have required an incredible amount of computational power. Instead, Qin and his colleagues used classical molecular dynamics — a mathematical technique based on a “force field” potential function, or a simplified version of the interactions between atoms — that enabled them to efficiently calculate interactions within larger atomic systems.

The researchers then built an atom-level sandwich model of graphene, water, and a cell membrane, based on the group’s simplified force field. They carried out molecular dynamics simulations in which they changed the amount of power applied to the graphene, as well as the thickness of the intermediate water layer, and observed the amount of heat that carried over from the graphene to the cell membrane.

Watery crystals

Because the stiffness of graphene and biological tissue is so different, Qin and his colleagues expected that heat would conduct rather poorly between the two materials, building up steeply in the graphene before flooding and overheating the cell membrane. However, the intermediate water layer helped dissipate this heat, easing its conduction and preventing a temperature spike in the cell membrane.

Looking more closely at the interactions within this interface, the researchers made a surprising discovery: Within the sandwich model, the water, pressed against graphene’s chicken-wire pattern, morphed into a similar crystal-like structure.

“Graphene’s lattice acts like a template to guide the water to form network structures,” Qin explains. “The water acts more like a solid material and makes the stiffness transition from graphene and membrane less abrupt. We think this helps heat to conduct from graphene to the membrane side.”

The group varied the thickness of the intermediate water layer in simulations, and found that a 1-nanometer-wide layer of water helped to dissipate heat very effectively. In terms of the power applied to the system, they calculated that about a megawatt of power per meter squared, applied in tiny, microsecond bursts, was the most power that could be applied to the interface without overheating the cell membrane.

Qin says going forward, implant designers can use the group’s model and simulations to determine the critical power requirements for graphene devices of different dimensions. As for how they might practically control the thickness of the intermediate water layer, he says graphene’s surface may be modified to attract a particular number of water molecules.

“I think graphene provides a very promising candidate for implantable devices,” Qin says. “Our calculations can provide knowledge for designing these devices in the future, for specific applications, like sensors, monitors, and other biomedical applications.”

This research was supported in part by the MIT International Science and Technology Initiative (MISTI): MIT-China Seed Fund, the National Natural Science Foundation of China, DARPA [US Defense Advanced Research Projects Agency], the Department of Defense (DoD) Office of Naval Research, the DoD Multidisciplinary Research Initiatives program, the MIT Energy Initiative, and the National Science Foundation.

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

Intercalated water layers promote thermal dissipation at bio–nano interfaces by Yanlei Wang, Zhao Qin, Markus J. Buehler, & Zhiping Xu. Nature Communications 7, Article number: 12854 doi:10.1038/ncomms12854 Published 23 September 2016

This paper is open access.

An examination of nanomanufacturing and nanofabrication

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Michael Berger has written an Aug. 11, 2016 Nanowerk Spotlight review of a paper about nanomanufacturing (Note: A link has been removed),

… the path to greater benefits – whether economic, social, or environmental – from nanomanufactured goods and services is not yet clear. A recent review article in ACS Nano (“Nanomanufacturing: A Perspective”) by J. Alexander Liddle and Gregg M. Gallatin, takes silicon integrated circuit manufacturing as a baseline in order to consider the factors involved in matching processes with products, examining the characteristics and potential of top-down and bottom-up processes, and their combination.

The authors also discuss how a careful assessment of the way in which function can be made to follow form can enable high-volume manufacturing of nanoscale structures with the desired useful, and exciting, properties.

Although often used interchangeably, it makes sense to distinguish between nanofabrication and nanomanufacturing using the criterion of economic viability, suggested by the connotations of industrial scale and profitability associated with the word ‘manufacturing’.

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

Nanomanufacturing: A Perspective by J. Alexander Liddle and Gregg M. Gallatin. ACS Nano, 2016, 10 (3), pp 2995–3014 DOI: 10.1021/acsnano.5b03299 Publication Date (Web): February 10, 2016

Copyright This article not subject to U.S. Copyright. Published 2016 by the American Chemical Society

This paper is behind a paywall.

Luckily for those who’d like a little more information before purchase, Berger’s review provides some insight into the study additional to what you’ll find in the abstract,

Nanomanufacturing, as the authors define it in their article, therefore, has the salient characteristic of being a source of money, while nanofabrication is often a sink.

To supply some background and indicate the scale of the nanomanufacturing challenge, the figure below shows the selling price ($·m-2) versus the annual production (m2) for a variety of nanoenabled or potentially nanoenabled products. The overall global market sizes are also indicated. It is interesting to note that the selling price spans 5 orders of magnitude, the production six, and the market size three. Although there is no strong correlation between the variables,
market price and size nanoenabled product
Log-log plot of the approximate product selling price ($·m-2) versus global annual production (m2) for a variety of nanoenabled, or potentially nanoenabled products. Approximate market sizes (2014) are shown next to each point. (Reprinted with permission by American Chemical Society)

market price and size nanoenabled product
Log-log plot of the approximate product selling price ($·m-2) versus global annual production (m2) for a variety of nanoenabled, or potentially nanoenabled products. Approximate market sizes (2014) are shown next to each point. (Reprinted with permission by American Chemical Society)

I encourage anyone interested in nanomanufacturing to read Berger’s article in its entirety as there is more detail and there are more figures to illustrate the points being made. He ends his review with this,

“Perhaps the most exciting prospect is that of creating dynamical nanoscale systems that are capable of exhibiting much richer structures and functionality. Whether this is achieved by learning how to control and engineer biological systems directly, or by building systems based on the same principles, remains to be seen, but will undoubtedly be disruptive and quite probably revolutionary.”

I find the reference to biological systems quite interesting especially in light of the recent launch of DARPA’s (US Defense Advanced Research Projects Agency) Engineered Living Materials (ELM) program (see my Aug. 9, 2016 posting).

Do you have a proposal for living building materials?

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DARPA (US Defense Advanced Research Projects Agency) has launched a program called Engineered Living Materials (ELM) and issued an invitation. From an Aug. 9, 2016 news item on Nanowerk,

The structural materials that are currently used to construct homes, buildings, and infrastructure are expensive to produce and transport, wear out due to age and damage, and have limited ability to respond to changes in their immediate surroundings. Living biological materials—bone, skin, bark, and coral, for example—have attributes that provide advantages over the non-living materials people build with, in that they can be grown where needed, self-repair when damaged, and respond to changes in their surroundings. The inclusion of living materials in human-built environments could offer significant benefits; however, today scientists and engineers are unable to easily control the size and shape of living materials in ways that would make them useful for construction.

DARPA is launching the Engineered Living Materials (ELM) program with a goal of creating a new class of materials that combines the structural properties of traditional building materials with attributes of living systems. Living materials represent a new opportunity to leverage engineered biology to solve existing problems associated with the construction and maintenance of built environments, and to create new capabilities to craft smart infrastructure that dynamically responds to its surroundings.

An Aug. 5, 2016 DARPA news release, which originated the news item, explains further (Note: A link has been removed),

“The vision of the ELM program is to grow materials on demand where they are needed,” said ELM program manager Justin Gallivan. “Imagine that instead of shipping finished materials, we can ship precursors and rapidly grow them on site using local resources. And, since the materials will be alive, they will be able to respond to changes in their environment and heal themselves in response to damage.”

Grown materials are not entirely new, but their current manifestations differ substantially from the materials Gallivan envisions. For instance, biologically sourced structural materials can already be grown into specified sizes and shapes from inexpensive feedstocks; packing materials derived from fungal mycelium and building blocks made from bacteria and sand are two modern examples. And, of course, wood has been used for ages. However, these products are rendered inert during the manufacturing process, so they exhibit few of their components’ original biological advantages. Scientists are making progress with three-dimensional printing of living tissues and organs, using scaffolding materials that sustain the long-term viability of the living cells. These cells are derived from existing natural tissues, however, and are not engineered to perform synthetic functions. And current cell-printing methods are too expensive to produce building materials at necessary scales.

ELM looks to merge the best features of these existing technologies and build on them to create hybrid materials composed of non-living scaffolds that give structure to and support the long-term viability of engineered living cells. DARPA intends to develop platform technologies that are scalable and generalizable to facilitate a quick transition from laboratory to commercial applications.

The long-term objective of the ELM program is to develop an ability to engineer structural properties directly into the genomes of biological systems so that neither scaffolds nor external development cues are needed for an organism to realize the desired shape and properties. Achieving this goal will require significant breakthroughs in scientists’ understanding of developmental pathways and how those pathways direct the three-dimensional development of multicellular systems.

Work on ELM will be fundamental research carried out in controlled laboratory settings. DARPA does not anticipate environmental release during the program.

For anyone who’s interested in participating in the program, there’s an announcement (download the PDF for more details) featuring a Proposers Day event on Aug. 26, 2016 being held in Arlington, Virginia,

The Proposers Day objectives are:

1) To introduce the science and technology community (industry, academia, and government) to the ELM program vision and goals;

2) To facilitate interaction between investigators that may have capabilities to develop elements of interest and relevance to ELM goals; and

3) To encourage and promote teaming arrangements among organizations that have the relevant expertise, research facilities and capabilities for executing research and development responsive to the ELM program goals.

The Proposers Day will include overview presentations and optional sidebar meetings where potential proposers can discuss ideas for proposal submissions with the Government team.

The goal of the DARPA ELM program is to explore and develop living materials that combine the structural properties of traditional building materials with attributes of living systems, including the ability to rapidly grow, to self-repair, and to adapt to the environment. Living materials represent a new opportunity to leverage engineered biology to solve existing problems associated with the construction and maintenance of our built environments, as well as to create new capabilities to craft smart infrastructure that dynamically responds to our surroundings. The specific program objectives are to develop design tools and methods that enable the engineering of structural features into cellular systems that function as living materials, thereby opening up a new design space for building technology. These new methods will be validated by the production of living materials that can reproduce, self-organize and self-heal.

You can register for the event  here. Register by 12 pm (noon) ET on Aug. 23, 2016.

Nanotechnology and cybersecurity risks

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Gregory Carpenter has written a gripping (albeit somewhat exaggerated) piece for Signal, a publication of the  Armed Forces Communications and Electronics Association (AFCEA) about cybersecurity issues and  nanomedicine endeavours. From Carpenter’s Jan. 1, 2016 article titled, When Lifesaving Technology Can Kill; The Cyber Edge,

The exciting advent of nanotechnology that has inspired disruptive and lifesaving medical advances is plagued by cybersecurity issues that could result in the deaths of people that these very same breakthroughs seek to heal. Unfortunately, nanorobotic technology has suffered from the same security oversights that afflict most other research and development programs.

Nanorobots, or small machines [or nanobots[, are vulnerable to exploitation just like other devices.

At the moment, the issue of cybersecurity exploitation is secondary to making nanobots, or nanorobots, dependably functional. As far as I’m aware, there is no such nanobot. Even nanoparticles meant to function as packages for drug delivery have not been perfected (see one of the controversies with nanomedicine drug delivery described in my Nov. 26, 2015 posting).

That said, Carpenter’s point about cybersecurity is well taken since security features are often overlooked in new technology. For example, automated banking machines (ABMs) had woefully poor (inadequate, almost nonexistent) security when they were first introduced.

Carpenter outlines some of the problems that could occur, assuming some of the latest research could be reliably  brought to market,

The U.S. military has joined the fray of nanorobotic experimentation, embarking on revolutionary research that could lead to a range of discoveries, from unraveling the secrets of how brains function to figuring out how to permanently purge bad memories. Academia is making amazing advances as well. Harnessing progress by Harvard scientists to move nanorobots within humans, researchers at the University of Montreal, Polytechnique Montreal and Centre Hospitalier Universitaire Sainte-Justine are using mobile nanoparticles inside the human brain to open the blood-brain barrier, which protects the brain from toxins found in the circulatory system.

…

A different type of technology presents a risk similar to the nanoparticles scenario. A DARPA-funded program known as Restoring Active Memory (RAM) addresses post-traumatic stress disorder, attempting to overcome memory deficits by developing neuroprosthetics that bridge gaps in an injured brain. In short, scientists can wipe out a traumatic memory, and they hope to insert a new one—one the person has never actually experienced. Someone could relish the memory of a stroll along the French Riviera rather than a terrible firefight, even if he or she has never visited Europe.

As an individual receives a disruptive memory, a cyber criminal could manage to hack the controls. Breaches of the brain could become a reality, putting humans at risk of becoming zombie hosts [emphasis mine] for future virus deployments. …

At this point, the ‘zombie’ scenario Carpenter suggests seems a bit over-the-top but it does hearken to the roots of the zombie myth where the undead aren’t mindlessly searching for brains but are humans whose wills have been overcome. Mike Mariani in an Oct. 28, 2015 article for The Atlantic has presented a thought-provoking history of zombies,

… the zombie myth is far older and more rooted in history than the blinkered arc of American pop culture suggests. It first appeared in Haiti in the 17th and 18th centuries, when the country was known as Saint-Domingue and ruled by France, which hauled in African slaves to work on sugar plantations. Slavery in Saint-Domingue under the French was extremely brutal: Half of the slaves brought in from Africa were worked to death within a few years, which only led to the capture and import of more. In the hundreds of years since, the zombie myth has been widely appropriated by American pop culture in a way that whitewashes its origins—and turns the undead into a platform for escapist fantasy.

The original brains-eating fiend was a slave not to the flesh of others but to his own. The zombie archetype, as it appeared in Haiti and mirrored the inhumanity that existed there from 1625 to around 1800, was a projection of the African slaves’ relentless misery and subjugation. Haitian slaves believed that dying would release them back to lan guinée, literally Guinea, or Africa in general, a kind of afterlife where they could be free. Though suicide was common among slaves, those who took their own lives wouldn’t be allowed to return to lan guinée. Instead, they’d be condemned to skulk the Hispaniola plantations for eternity, an undead slave at once denied their own bodies and yet trapped inside them—a soulless zombie.

I recommend reading Mariani’s article although I do have one nit to pick. I can’t find a reference to brain-eating zombies until George Romero’s introduction of the concept in his movies. This Zombie Wikipedia entry seems to be in agreement with my understanding (if I’m wrong, please do let me know and, if possible, provide a link to the corrective text).

Getting back to Carpenter and cybersecurity with regard to nanomedicine, while his scenarios may seem a trifle extreme it’s precisely the kind of thinking you need when attempting to anticipate problems. I do wish he’d made clear that the technology still has a ways to go.

DARPA (US Defense Advanced Research Project Agency) ‘Atoms to Product’ program launched

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It took over a year after announcing the ‘Atoms to Product’ program in 2014 for DARPA (US Defense Advanced Research Projects Agency) to select 10 proponents for three projects. Before moving onto the latest announcement, here’s a description of the ‘Atoms to Product’ program from its Aug. 27, 2014 announcement on Nanowerk,

Many common materials exhibit different and potentially useful characteristics when fabricated at extremely small scales—that is, at dimensions near the size of atoms, or a few ten-billionths of a meter. These “atomic scale” or “nanoscale” properties include quantized electrical characteristics, glueless adhesion, rapid temperature changes, and tunable light absorption and scattering that, if available in human-scale products and systems, could offer potentially revolutionary defense and commercial capabilities. Two as-yet insurmountable technical challenges, however, stand in the way: Lack of knowledge of how to retain nanoscale properties in materials at larger scales, and lack of assembly capabilities for items between nanoscale and 100 microns—slightly wider than a human hair.

DARPA has created the Atoms to Product (A2P) program to help overcome these challenges. The program seeks to develop enhanced technologies for assembling atomic-scale pieces. It also seeks to integrate these components into materials and systems from nanoscale up to product scale in ways that preserve and exploit distinctive nanoscale properties.

DARPA’s Atoms to Product (A2P) program seeks to develop enhanced technologies for assembling nanoscale items, and integrating these components into materials and systems from nanoscale up to product scale in ways that preserve and exploit distinctive nanoscale properties.

A Dec. 29, 2015 news item on Nanowerk features the latest about the project,

DARPA recently selected 10 performers to tackle this challenge: Zyvex Labs, Richardson, Texas; SRI, Menlo Park, California; Boston University, Boston, Massachusetts; University of Notre Dame, South Bend, Indiana; HRL Laboratories, Malibu, California; PARC, Palo Alto, California; Embody, Norfolk, Virginia; Voxtel, Beaverton, Oregon; Harvard University, Cambridge, Massachusetts; and Draper Laboratory, Cambridge, Massachusetts.

A Dec. 29, 2015 DARPA news release, which originated the news item, offers more information and an image illustrating the type of advances already made by one of the successful proponents,

DARPA recently launched its Atoms to Product (A2P) program, with the goal of developing technologies and processes to assemble nanometer-scale pieces—whose dimensions are near the size of atoms—into systems, components, or materials that are at least millimeter-scale in size. At the heart of that goal was a frustrating reality: Many common materials, when fabricated at nanometer-scale, exhibit unique and attractive “atomic-scale” behaviors including quantized current-voltage behavior, dramatically lower melting points and significantly higher specific heats—but they tend to lose these potentially beneficial traits when they are manufactured at larger “product-scale” dimensions, typically on the order of a few centimeters, for integration into devices and systems.

…

“The ability to assemble atomic-scale pieces into practical components and products is the key to unlocking the full potential of micromachines,” said John Main, DARPA program manager. “The DARPA Atoms to Product Program aims to bring the benefits of microelectronic-style miniaturization to systems and products that combine mechanical, electrical, and chemical processes.”

The program calls for closing the assembly gap in two steps: From atoms to microns and from microns to millimeters. Performers are tasked with addressing one or both of these steps and have been assigned to one of three working groups, each with a distinct focus area.

…

A2P

Image caption: Microscopic tools such as this nanoscale “atom writer” can be used to fabricate minuscule light-manipulating structures on surfaces. DARPA has selected 10 performers for its Atoms to Product (A2P) program whose goal is to develop technologies and processes to assemble nanometer-scale pieces—whose dimensions are near the size of atoms—into systems, components, or materials that are at least millimeter-scale in size. (Image credit: Boston University)

Here’s more about the projects and the performers (proponents) from the A2P performers page on the DARPA website,

Nanometer to Millimeter in a Single System – Embody, Draper and Voxtel

Current methods to treat ligament injuries in warfighters [also known as, soldiers]—which account for a significant portion of reported injuries—often fail to restore pre-injury performance, due to surgical complexities and an inadequate supply of donor tissue. Embody is developing reinforced collagen nanofibers that mimic natural ligaments and replicate the biological and biomechanical properties of native tissue. Embody aims to create a new standard of care and restore pre-injury performance for warfighters and sports injury patients at a 50% reduction compared to current costs.

Radio Frequency (RF) systems (e.g., cell phones, GPS) have performance limits due to alternating current loss. In lower frequency power systems this is addressed by braiding the wires, but this is not currently possibly in cell phones due to an inability to manufacture sufficiently small braided wires. Draper is developing submicron wires that can be braided using DNA self-assembly methods. If successful, portable RF systems will be more power efficient and able to send 10 times more information in a given channel.

For seamless control of structures, physics and surface chemistry—from the atomic-level to the meter-level—Voxtel Inc. and partner Oregon State University are developing an efficient, high-rate, fluid-based manufacturing process designed to imitate nature’s ability to manufacture complex multimaterial products across scales. Historically, challenges relating to the cost of atomic-level control, production speed, and printing capability have been effectively insurmountable. This team’s new process will combine synthesis and delivery of materials into a massively parallel inkjet operation that draws from nature to achieve a DNA-like mediated assembly. The goal is to assemble complex, 3-D multimaterial mixed organic and inorganic products quickly and cost-effectively—directly from atoms.

Optical Metamaterial Assembly – Boston University, University of Notre Dame, HRL and PARC.

Nanoscale devices have demonstrated nearly unlimited power and functionality, but there hasn’t been a general- purpose, high-volume, low-cost method for building them. Boston University is developing an atomic calligraphy technique that can spray paint atoms with nanometer precision to build tunable optical metamaterials for the photonic battlefield. If successful, this capability could enhance the survivability of a wide range of military platforms, providing advanced camouflage and other optical illusions in the visual range much as stealth technology has enabled in the radar range.

The University of Notre Dame is developing massively parallel nanomanufacturing strategies to overcome the requirement today that most optical metamaterials must be fabricated in “one-off” operations. The Notre Dame project aims to design and build optical metamaterials that can be reconfigured to rapidly provide on-demand, customized optical capabilities. The aim is to use holographic traps to produce optical “tiles” that can be assembled into a myriad of functional forms and further customized by single-atom electrochemistry. Integrating these materials on surfaces and within devices could provide both warfighters and platforms with transformational survivability.

HRL Laboratories is working on a fast, scalable and material-agnostic process for improving infrared (IR) reflectivity of materials. Current IR-reflective materials have limited use, because reflectivity is highly dependent on the specific angle at which light hits the material. HRL is developing a technique for allowing tailorable infrared reflectivity across a variety of materials. If successful, the process will enable manufacturable materials with up to 98% IR reflectivity at all incident angles.

PARC is working on building the first digital MicroAssembly Printer, where the “inks” are micrometer-size particles and the “image” outputs are centimeter-scale and larger assemblies. The goal is to print smart materials with the throughput and cost of laser printers, but with the precision and functionality of nanotechnology. If successful, the printer would enable the short-run production of large, engineered, customized microstructures, such as metamaterials with unique responses for secure communications, surveillance and electronic warfare.

Flexible, General Purpose Assembly – Zyvex, SRI, and Harvard.

Zyvex aims to create nano-functional micron-scale devices using customizable and scalable manufacturing that is top-down and atomically precise. These high-performance electronic, optical, and nano-mechanical components would be assembled by SRI micro-robots into fully-functional devices and sub-systems such as ultra-sensitive sensors for threat detection, quantum communication devices, and atomic clocks the size of a grain of sand.

SRI’s Levitated Microfactories will seek to combine the precision of MEMS [micro-electromechanical systems] flexures with the versatility and range of pick-and-place robots and the scalability of swarms [an idea Michael Crichton used in his 2002 novel Prey to induce horror] to assemble and electrically connect micron and millimeter components to build stronger materials, faster electronics, and better sensors.

Many high-impact, minimally invasive surgical techniques are currently performed only by elite surgeons due to the lack of tactile feedback at such small scales relative to what is experienced during conventional surgical procedures. Harvard is developing a new manufacturing paradigm for millimeter-scale surgical tools using low-cost 2D layer-by-layer processes and assembly by folding, resulting in arbitrarily complex meso-scale 3D devices. The goal is for these novel tools to restore the necessary tactile feedback and thereby nurture a new degree of dexterity to perform otherwise demanding micro- and minimally invasive surgeries, and thus expand the availability of life-saving procedures.

Sidebar

‘Sidebar’ is my way of indicating these comments have little to do with the matter at hand but could be interesting factoids for you.

First, Zyvex Labs was last mentioned here in a Sept. 10, 2014 posting titled: OCSiAL will not be acquiring Zyvex. Notice that this  announcement was made shortly after DARPA’s A2P program was announced and that OCSiAL is one of RUSNANO’s (a Russian funding agency focused on nanotechnology) portfolio companies (see my Oct. 23, 2015 posting for more).

HRL Laboratories, mentioned here in an April 19, 2012 posting mostly concerned with memristors (nanoscale devices that mimic neural or synaptic plasticity), has its roots in Howard Hughes’s research laboratories as noted in the posting. In 2012, HRL was involved in another DARPA project, SyNAPSE.

Finally and minimally, PARC also known as, Xerox PARC, was made famous by Steven Jobs and Steve Wozniak when they set up their own company (Apple) basing their products on innovations that PARC had rejected. There are other versions of the story and one by Malcolm Gladwell for the New Yorker May 16, 2011 issue which presents a more complicated and, at times, contradictory version of that particular ‘origins’ story.

A pragmatic approach to alternatives to animal testing

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Retitled and cross-posted from the June 30, 2015 posting (Testing times: the future of animal alternatives) on the International Innovation blog (a CORDIS-listed project dissemination partner for FP7 and H2020 projects).

Maryse de la Giroday explains how emerging innovations can provide much-needed alternatives to animal testing. She also shares highlights of the 9th World Congress on Alternatives to Animal Testing.

‘Guinea pigging’ is the practice of testing drugs that have passed in vitro and in vivo tests on healthy humans in a Phase I clinical trial. In fact, healthy humans can make quite a bit of money as guinea pigs. The practice is sufficiently well-entrenched that there is a magazine, Guinea Pig Zero, devoted to professionals. While most participants anticipate some unpleasant side effects, guinea pigging can sometimes be a dangerous ‘profession’.

HARMFUL TO HEALTH

One infamous incident highlighting the dangers of guinea pigging occurred in 2006 at Northwick Park Hospital outside London. Volunteers were offered £2,000 to participate in a Phase I clinical trial to test a prospective treatment – a monoclonal antibody designed for rheumatoid arthritis and multiple sclerosis. The drug, called TGN1412, caused catastrophic systemic organ failure in participants. All six individuals receiving the drug required hospital treatment. One participant reportedly underwent amputation of fingers and toes. Another reacted with symptoms comparable to John Merrick, the Elephant Man.

The root of the disaster lay in subtle immune system differences between humans and cynomolgus monkeys – the model animal tested prior to the clinical trial. The drug was designed for the CD28 receptor on T cells. The monkeys’ receptors closely resemble those found in humans. However, unlike these monkeys, humans have other immune cells that carry CD28. The trial participants received a starting dosage that was 0.2 per cent of what the monkeys received in their final tests, but failure to take these additional receptors into account meant a dosage that was supposed to occupy 10 per cent of the available CD28 receptors instead occupied 90 per cent. After the event, a Russian inventor purchased the commercial rights to the drug and renamed it TAB08. It has been further developed by Russian company, TheraMAB, and TAB08 is reportedly in Phase II clinical trials.

HUMAN-ON-A-CHIP AND ORGANOID PROJECTS

While animal testing has been a powerful and useful tool for determining safe usage for pharmaceuticals and other types of chemicals, it is also a cruel and imperfect practice. Moreover, it typically only predicts 30-60 per cent of human responses to new drugs. Nanotechnology and other emerging innovations present possibilities for reducing, and in some cases eliminating, the use of animal models.

People for the Ethical Treatment of Animals (PETA), still better known for its publicity stunts, maintains a webpage outlining a number of alternatives including in silico testing (computer modelling), and, perhaps most interestingly, human-on-a-chip and organoid (tissue engineering) projects.

Organ-on-a-chip projects use stem cells to create human tissues that replicate the functions of human organs. Discussions about human-on-a-chip activities – a phrase used to describe 10 interlinked organ chips – were a highlight of the 9th World Congress on Alternatives to Animal Testing held in Prague, Czech Republic, last year. One project highlighted at the event was a joint US National Institutes of Health (NIH), US Food and Drug Administration (FDA) and US Defense Advanced Research Projects Agency (DARPA) project led by Dan Tagle that claimed it would develop functioning human-on-a-chip by 2017. However, he and his team were surprisingly close-mouthed and provided few details making it difficult to assess how close they are to achieving their goal.

By contrast, Uwe Marx – Leader of the ‘Multi-Organ-Chip’ programme in the Institute of Biotechnology at the Technical University of Berlin and Scientific Founder of TissUse, a human-on-a-chip start-up company – claims to have sold two-organ chips. He also claims to have successfully developed a four-organ chip and that he is on his way to building a human-on-a-chip. Though these chips remain to be seen, if they are, they will integrate microfluidics, cultured cells and materials patterned at the nanoscale to mimic various organs, and will allow chemical testing in an environment that somewhat mirrors a human.

Another interesting alternative for animal testing is organoids – a feature in regenerative medicine that can function as test sites. Engineers based at Cornell University recently published a paper on their functional, synthetic immune organ. Inspired by the lymph node, the organoid is comprised of gelatin-based biomaterials, which are reinforced with silicate nanoparticles (to keep the tissue from melting when reaching body temperature) and seeded with cells allowing it to mimic the anatomical microenvironment of a lymphatic node. It behaves like its inspiration converting B cells to germinal centres which activate, mature and mutate antibody genes when the body is under attack. The engineers claim to be able to control the immune response and to outperform 2D cultures with their 3D organoid. If the results are reproducible, the organoid could be used to develop new therapeutics.

Maryse de la Giroday is a science communications consultant and writer.

Full disclosure: Maryse de la Giroday received transportation and accommodation for the 9th World Congress on Alternatives to Animal Testing from SEURAT-1, a European Union project, making scientific inquiries to facilitate the transition to animal testing alternatives, where possible.

ETA July 1, 2015: I would like to acknowledge more sources for the information in this article,

Sources:

The guinea pigging term, the ‘professional aspect, the Northwick Park story, and the Guinea Pig Zero magazine can be found in Carl Elliot’s excellent 2006 story titled ‘Guinea-Pigging’ for New Yorker magazine.

http://www.newyorker.com/magazine/2008/01/07/guinea-pigging

Information about the drug used in the Northwick Park Hospital disaster, the sale of the rights to a Russian inventor, and the June 2015 date for the current Phase II clinical trials were found in this Wikipedia essay titled, TGN 1412.

http://en.wikipedia.org/wiki/TGN1412

Additional information about the renamed drug, TAB08 and its Phase II clinical trials was found on (a) a US government website for information on clinical trials, (b) in a Dec. 2014 (?) TheraMAB  advertisement in a Nature group magazine and a Jan. 2014 press release,

https://www.clinicaltrials.gov/ct2/show/NCT01990157?term=TAB08_RA01&rank=1

http://www.theramab.ru/TheraMAB_NAture.pdf

http://theramab.ru/en/news/phase_II

An April 2015 article (Experimental drug that injured UK volunteers resumes in human trials) by Owen Dyer for the British Medical Journal also mentioned the 2015 TheraMab Phase II clinical trials and provided information about the information about Macaque (cynomolgus) monkey tests.

http://www.bmj.com.proxy.lib.sfu.ca/content/350/bmj.h1831

BMJ 2015; 350 doi: http://dx.doi.org.proxy.lib.sfu.ca/10.1136/bmj.h1831 (Published 02 April 2015) Cite this as: BMJ 2015;350:h1831

A 2009 study by Christopher Horvath and Mark Milton somewhat contradicts the Dyer article’s contention that a species Macaque monkey was used as an animal model. (As the Dyer article is more recent and the Horvath/Milton analysis is more complex covering TGN 1412 in the context of other MAB drugs and their precursor tests along with specific TGN 1412 tests, I opted for the simple description.)

The TeGenero Incident [another name for the Northwick Park Accident] and the Duff Report Conclusions: A Series of Unfortunate Events or an Avoidable Event? by Christopher J. Horvath and Mark N. Milton. Published online before print February 24, 2009, doi: 10.1177/0192623309332986 Toxicol Pathol April 2009 vol. 37 no. 3 372-383

http://tpx.sagepub.com/content/37/3/372.full

Philippa Roxbuy’s May 24, 2013 BBC news online article provided confirmation and an additional detail or two about the Northwick Park Hospital accident. It notes that other models, in addition to animal models, are being developed.

http://www.bbc.com/news/health-22556736

Anne Ju’s excellent June 10,2015 news release about the Cornell University organoid (synthetic immune organ) project was very helpful.

http://www.news.cornell.edu/stories/2015/06/engineers-synthetic-immune-organ-produces-antibodies

There will also be a magazine article in International Innovation, which will differ somewhat from the blog posting, due to editorial style and other requirements.

ETA July 22, 2015: I now have a link to the magazine article.

Entangling thousands of atoms

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Quantum entanglement as an idea seems extraordinary to me like something from of the fevered imagination made possible only with certain kinds of hallucinogens. I suppose you could call theoretical physicists who’ve conceptualized entanglement a different breed as they don’t seem to need chemical assistance for their flights of fancy, which turn out to be reality. Researchers at MIT (Massachusetts Institute of Technology) and the University of Belgrade (Serbia) have entangled thousands of atoms with a single photon according to a March 26, 2015 news item on Nanotechnology Now,

Physicists from MIT and the University of Belgrade have developed a new technique that can successfully entangle 3,000 atoms using only a single photon. The results, published today in the journal Nature, represent the largest number of particles that have ever been mutually entangled experimentally.

The researchers say the technique provides a realistic method to generate large ensembles of entangled atoms, which are key components for realizing more-precise atomic clocks.

“You can make the argument that a single photon cannot possibly change the state of 3,000 atoms, but this one photon does — it builds up correlations that you didn’t have before,” says Vladan Vuletic, the Lester Wolfe Professor in MIT’s Department of Physics, and the paper’s senior author. “We have basically opened up a new class of entangled states we can make, but there are many more new classes to be explored.”

A March 26, 2015 MIT news release by Jennifer Chu (also on EurekAlert but dated March 25, 2015), which originated the news item, describes entanglement with particular attention to how it relates to atomic timekeeping,

Entanglement is a curious phenomenon: As the theory goes, two or more particles may be correlated in such a way that any change to one will simultaneously change the other, no matter how far apart they may be. For instance, if one atom in an entangled pair were somehow made to spin clockwise, the other atom would instantly be known to spin counterclockwise, even though the two may be physically separated by thousands of miles.

The phenomenon of entanglement, which physicist Albert Einstein once famously dismissed as “spooky action at a distance,” is described not by the laws of classical physics, but by quantum mechanics, which explains the interactions of particles at the nanoscale. At such minuscule scales, particles such as atoms are known to behave differently from matter at the macroscale.

Scientists have been searching for ways to entangle not just pairs, but large numbers of atoms; such ensembles could be the basis for powerful quantum computers and more-precise atomic clocks. The latter is a motivation for Vuletic’s group.

Today’s best atomic clocks are based on the natural oscillations within a cloud of trapped atoms. As the atoms oscillate, they act as a pendulum, keeping steady time. A laser beam within the clock, directed through the cloud of atoms, can detect the atoms’ vibrations, which ultimately determine the length of a single second.

“Today’s clocks are really amazing,” Vuletic says. “They would be less than a minute off if they ran since the Big Bang — that’s the stability of the best clocks that exist today. We’re hoping to get even further.”

The accuracy of atomic clocks improves as more and more atoms oscillate in a cloud. Conventional atomic clocks’ precision is proportional to the square root of the number of atoms: For example, a clock with nine times more atoms would only be three times as accurate. If these same atoms were entangled, a clock’s precision could be directly proportional to the number of atoms — in this case, nine times as accurate. The larger the number of entangled particles, then, the better an atomic clock’s timekeeping.

It seems weak lasers make big entanglements possible (from the news release),

Scientists have so far been able to entangle large groups of atoms, although most attempts have only generated entanglement between pairs in a group. Only one team has successfully entangled 100 atoms — the largest mutual entanglement to date, and only a small fraction of the whole atomic ensemble.

Now Vuletic and his colleagues have successfully created a mutual entanglement among 3,000 atoms, virtually all the atoms in the ensemble, using very weak laser light — down to pulses containing a single photon. The weaker the light, the better, Vuletic says, as it is less likely to disrupt the cloud. “The system remains in a relatively clean quantum state,” he says.

The researchers first cooled a cloud of atoms, then trapped them in a laser trap, and sent a weak laser pulse through the cloud. They then set up a detector to look for a particular photon within the beam. Vuletic reasoned that if a photon has passed through the atom cloud without event, its polarization, or direction of oscillation, would remain the same. If, however, a photon has interacted with the atoms, its polarization rotates just slightly — a sign that it was affected by quantum “noise” in the ensemble of spinning atoms, with the noise being the difference in the number of atoms spinning clockwise and counterclockwise.

“Every now and then, we observe an outgoing photon whose electric field oscillates in a direction perpendicular to that of the incoming photons,” Vuletic says. “When we detect such a photon, we know that must have been caused by the atomic ensemble, and surprisingly enough, that detection generates a very strongly entangled state of the atoms.”

Vuletic and his colleagues are currently using the single-photon detection technique to build a state-of-the-art atomic clock that they hope will overcome what’s known as the “standard quantum limit” — a limit to how accurate measurements can be in quantum systems. Vuletic says the group’s current setup may be a step toward developing even more complex entangled states.

“This particular state can improve atomic clocks by a factor of two,” Vuletic says. “We’re striving toward making even more complicated states that can go further.”

This research was supported in part by the National Science Foundation, the Defense Advanced Research Projects Agency, and the Air Force Office of Scientific Research.

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

Entanglement with negative Wigner function of almost 3,000 atoms heralded by one photon by Robert McConnell, Hao Zhang, Jiazhong Hu, Senka Ćuk & Vladan Vuletić. Nature 519 439–442 (26 March 2015) doi:10.1038/nature14293 Published online 25 March 2015

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

This image illustrates the entanglement of a large number of atoms. The atoms, shown in purple, are shown mutually entangled with one another. Image: Christine Daniloff/MIT and Jose-Luis Olivares/MIT

This image illustrates the entanglement of a large number of atoms. The atoms, shown in purple, are shown mutually entangled with one another.
Image: Christine Daniloff/MIT and Jose-Luis Olivares/MIT

Self-organizing nanotubes and nonequilibrium systems provide insights into evolution and artificial life

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If you’re interested in the second law of thermodynamics, this Feb. 10, 2015 news item on ScienceDaily provides some insight into the second law, self-organized systems, and evolution,

The second law of thermodynamics tells us that all systems evolve toward a state of maximum entropy, wherein all energy is dissipated as heat, and no available energy remains to do work. Since the mid-20th century, research has pointed to an extension of the second law for nonequilibrium systems: the Maximum Entropy Production Principle (MEPP) states that a system away from equilibrium evolves in such a way as to maximize entropy production, given present constraints.

Now, physicists Alexey Bezryadin, Alfred Hubler, and Andrey Belkin from the University of Illinois at Urbana-Champaign, have demonstrated the emergence of self-organized structures that drive the evolution of a non-equilibrium system to a state of maximum entropy production. The authors suggest MEPP underlies the evolution of the artificial system’s self-organization, in the same way that it underlies the evolution of ordered systems (biological life) on Earth. …

A Feb. 10, 2015 University of Illinois College of Engineering news release (also on EurekAlert), which originated the news item, provides more detail about the theory and the research,

MEPP may have profound implications for our understanding of the evolution of biological life on Earth and of the underlying rules that govern the behavior and evolution of all nonequilibrium systems. Life emerged on Earth from the strongly nonequilibrium energy distribution created by the Sun’s hot photons striking a cooler planet. Plants evolved to capture high energy photons and produce heat, generating entropy. Then animals evolved to eat plants increasing the dissipation of heat energy and maximizing entropy production.

In their experiment, the researchers suspended a large number of carbon nanotubes in a non-conducting non-polar fluid and drove the system out of equilibrium by applying a strong electric field. Once electrically charged, the system evolved toward maximum entropy through two distinct intermediate states, with the spontaneous emergence of self-assembled conducting nanotube chains.

In the first state, the “avalanche” regime, the conductive chains aligned themselves according to the polarity of the applied voltage, allowing the system to carry current and thus to dissipate heat and produce entropy. The chains appeared to sprout appendages as nanotubes aligned themselves so as to adjoin adjacent parallel chains, effectively increasing entropy production. But frequently, this self-organization was destroyed through avalanches triggered by the heating and charging that emanates from the emerging electric current streams. (…)

“The avalanches were apparent in the changes of the electric current over time,” said Bezryadin.

“Toward the final stages of this regime, the appendages were not destroyed during the avalanches, but rather retracted until the avalanche ended, then reformed their connection. So it was obvious that the avalanches correspond to the ‘feeding cycle’ of the ‘nanotube inset’,” comments Bezryadin.

In the second relatively stable stage of evolution, the entropy production rate reached maximum or near maximum. This state is quasi-stable in that there were no destructive avalanches.

The study points to a possible classification scheme for evolutionary stages and a criterium for the point at which evolution of the system is irreversible—wherein entropy production in the self-organizing subsystem reaches its maximum possible value. Further experimentation on a larger scale is necessary to affirm these underlying principals, but if they hold true, they will prove a great advantage in predicting behavioral and evolutionary trends in nonequilibrium systems.

The authors draw an analogy between the evolution of intelligent life forms on Earth and the emergence of the wiggling bugs in their experiment. The researchers note that further quantitative studies are needed to round out this comparison. In particular, they would need to demonstrate that their “wiggling bugs” can multiply, which would require the experiment be reproduced on a significantly larger scale.

Such a study, if successful, would have implications for the eventual development of technologies that feature self-organized artificial intelligence, an idea explored elsewhere by co-author Alfred Hubler, funded by the Defense Advanced Research Projects Agency [DARPA]. [emphasis mine]

“The general trend of the evolution of biological systems seems to be this: more advanced life forms tend to dissipate more energy by broadening their access to various forms of stored energy,” Bezryadin proposes. “Thus a common underlying principle can be suggested between our self-organized clouds of nanotubes, which generate more and more heat by reducing their electrical resistance and thus allow more current to flow, and the biological systems which look for new means to find food, either through biological adaptation or by inventing more technologies.

“Extended sources of food allow biological forms to further grow, multiply, consume more food and thus produce more heat and generate entropy. It seems reasonable to say that real life organisms are still far from the absolute maximum of the entropy production rate. In both cases, there are ‘avalanches’ or ‘extinction events’, which set back this evolution. Only if all free energy given by the Sun is consumed, by building a Dyson sphere for example, and converted into heat then a definitely stable phase of the evolution can be expected.”

“Intelligence, as far as we know, is inseparable from life,” he adds. “Thus, to achieve artificial life or artificial intelligence, our recommendation would be to study systems which are far from equilibrium, with many degrees of freedom—many building blocks—so that they can self-organize and participate in some evolution. The entropy production criterium appears to be the guiding principle of the evolution efficiency.”

I am fascinated

  • (a) because this piece took an unexpected turn onto the topic of artificial life/artificial intelligence,
  • (b) because of my longstanding interest in artificial life/artificial intelligence,
  • (c) because of the military connection, and
  • (d) because this is the first time I’ve come across something that provides a bridge from fundamental particles to nanoparticles.

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

Self-Assembled Wiggling Nano-Structures and the Principle of Maximum Entropy Production by A. Belkin, A. Hubler, & A. Bezryadin. Scientific Reports 5, Article number: 8323 doi:10.1038/srep08323 Published 09 February 2015

Adding to my delight, this paper is open access.

See-through medical sensors from the University of Wisconsin-Madison

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This is quite the week for see-through medical devices based on graphene. A second team has developed a transparent sensor which could allow scientists to make observations of brain activity that are now impossible, according to an Oct. 20, 2014 University of Wisconsin-Madison news release (also on EurekAlert),

Neural researchers study, monitor or stimulate the brain using imaging techniques in conjunction with implantable sensors that allow them to continuously capture and associate fleeting brain signals with the brain activity they can see.

However, it’s difficult to see brain activity when there are sensors blocking the view.

“One of the holy grails of neural implant technology is that we’d really like to have an implant device that doesn’t interfere with any of the traditional imaging diagnostics,” says Justin Williams, the Vilas Distinguished Achievement Professor of biomedical engineering and neurological surgery at UW-Madison. “A traditional implant looks like a square of dots, and you can’t see anything under it. We wanted to make a transparent electronic device.”

The researchers chose graphene, a material gaining wider use in everything from solar cells to electronics, because of its versatility and biocompatibility. And in fact, they can make their sensors incredibly flexible and transparent because the electronic circuit elements are only 4 atoms thick—an astounding thinness made possible by graphene’s excellent conductive properties. “It’s got to be very thin and robust to survive in the body,” says Zhenqiang (Jack) Ma, the Lynn H. Matthias Professor and Vilas Distinguished Achievement Professor of electrical and computer engineering at UW-Madison. “It is soft and flexible, and a good tradeoff between transparency, strength and conductivity.”

Drawing on his expertise in developing revolutionary flexible electronics, he, Williams and their students designed and fabricated the micro-electrode arrays, which—unlike existing devices—work in tandem with a range of imaging technologies. “Other implantable micro-devices might be transparent at one wavelength, but not at others, or they lose their properties,” says Ma. “Our devices are transparent across a large spectrum—all the way from ultraviolet to deep infrared.”

The transparent sensors could be a boon to neuromodulation therapies, which physicians increasingly are using to control symptoms, restore function, and relieve pain in patients with diseases or disorders such as hypertension, epilepsy, Parkinson’s disease, or others, says Kip Ludwig, a program director for the National Institutes of Health neural engineering research efforts. “Despite remarkable improvements seen in neuromodulation clinical trials for such diseases, our understanding of how these therapies work—and therefore our ability to improve existing or identify new therapies—is rudimentary.”

Currently, he says, researchers are limited in their ability to directly observe how the body generates electrical signals, as well as how it reacts to externally generated electrical signals. “Clear electrodes in combination with recent technological advances in optogenetics and optical voltage probes will enable researchers to isolate those biological mechanisms. This fundamental knowledge could be catalytic in dramatically improving existing neuromodulation therapies and identifying new therapies.”

The advance aligns with bold goals set forth in President Barack Obama’s BRAIN (Brain Research through Advancing Innovative Neurotechnologies) Initiative. Obama announced the initiative in April 2013 as an effort to spur innovations that can revolutionize understanding of the brain and unlock ways to prevent, treat or cure such disorders as Alzheimer’s and Parkinson’s disease, post-traumatic stress disorder, epilepsy, traumatic brain injury, and others.

The UW-Madison researchers developed the technology with funding from the Reliable Neural-Interface Technology program at the Defense Advanced Research Projects Agency.

While the researchers centered their efforts around neural research, they already have started to explore other medical device applications. For example, working with researchers at the University of Illinois-Chicago, they prototyped a contact lens instrumented with dozens of invisible sensors to detect injury to the retina; the UIC team is exploring applications such as early diagnosis of glaucoma.

Here’s an image of the see-through medical implant,

Caption: A blue light shines through a clear implantable medical sensor onto a brain model. See-through sensors, which have been developed by a team of University of Wisconsin Madison engineers, should help neural researchers better view brain activity. Credit: Justin Williams research group

Caption: A blue light shines through a clear implantable medical sensor onto a brain model. See-through sensors, which have been developed by a team of University of Wisconsin Madison engineers, should help neural researchers better view brain activity.
Credit: Justin Williams research group

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

Graphene-based carbon-layered electrode array technology for neural imaging and optogenetic applications by Dong-Wook Park, Amelia A. Schendel, Solomon Mikael, Sarah K. Brodnick, Thomas J. Richner, Jared P. Ness, Mohammed R. Hayat, Farid Atry, Seth T. Frye, Ramin Pashaie, Sanitta Thongpang, Zhenqiang Ma, & Justin C. Williams. Nature Communications 5, Article number: 5258 doi:10.1038/ncomms6258 Published
20 October 2014

This is an open access paper.

DARPA (US Defense Advanced Research Projects Agency), which funds this work at the University of Wisconsin-Madison, has also provided an Oct. 20, 2014 news release (also published an an Oct. 27, 2014 news item on Nanowerk) describing this research from the military perspective, which may not be what you might expect. First, here’s a description of the DARPA funding programme underwriting this research, from DARPA’s Reliable Neural-Interface Technology (RE-NET) webpage,

Advancing technology for military uniforms, body armor and equipment have saved countless lives of our servicemembers injured on the battlefield.  Unfortunately, many of those survivors are seriously and permanently wounded, with unprecedented rates of limb loss and traumatic brain injury among our returning soldiers. This crisis has motivated great interest in the science of and technology for restoring sensorimotor functions lost to amputation and injury of the central nervous system. For a decade now, DARPA has been leading efforts aimed at ‘revolutionizing’ the state-of-the-art in prosthetic limbs, recently debuting 2 advanced mechatronic limbs for the upper extremity. These new devices are truly anthropomorphic and capable of performing dexterous manipulation functions that finally begin to approach the capabilities of natural limbs. However, in the absence of a high bandwidth, intuitive interface for the user, these limbs will never achieve their full potential in improving the quality of life for the wounded soldiers that could benefit from this advanced technology.

DARPA created the Reliable Neural-Interface Technology (RE-NET) program in 2010 to directly address the need for high performance neural interfaces to control dexterous functions made possible with advanced prosthetic limbs.  Specifically, RE-NET seeks to develop the technologies needed to reliably extract information from the nervous system, and to do so at a scale and rate necessary to control many degree-of-freedom (DOF) machines, such as high-performance prosthetic limbs. Prior to the DARPA RE-NET program, all existing methods to extract neural control signals were inadequate for amputees to control high-performance prostheses, either because the level of extracted information was too low or the functional lifetime was too short. However, recent technological advances create new opportunities to solve both of these neural-interface problems. For example, it is now feasible to develop high-resolution peripheral neuromuscular interfaces that increase the amount of information obtained from the peripheral nervous system.  Furthermore, advances in cortical microelectrode technologies are extending the durability of neural signals obtained from the brain, making it possible to create brain-controlled prosthetics that remain useful over the full lifetime of the patient.