Simon Fraser University – SCFC861Nanotechnology, The Next Big Idea: course Week 1

Yesterday (Oct. 23, 2014) I started teaching a course called, Nanotechnology: The Next Big Idea for Simon Fraser University’s (SFU) Continuing Studies programme and understand that students want a copy of the slides. Unfortunately, SFU does not have a system in place for continuing studies instructors to make their course materials available online to students, so, at the end of this post you will find a link to my Week One PowerPoint slides.

For those who may be mildly curious, here’s a description of the course and of what I was covering in the first week (from SFU’s course description webpage),

Nano what? Well, it’s the manipulation of matter on an atomic, molecular and supra-molecular scale. Considered obscure and still little understood by many outside the scientific community, even the term is contested. Is it nanoscience or nanotechnoogy? The answer is: it depends. It is epxected that nanotechnology will have a greater social impact than computers and the Internet.

We will explore the world of carbon nanotubes, graphene and other nanomaterials; the formal (government) and informatl (popular culture) discussions regarding risks and benefits; and Canada’s place in the international race underway to develop this emerging science and technology.

Week 1: Nanotechnology: The Nitty Gritty

What is nanotechnology? Even scientists have a problem explaining it especially since definitions for it are relatively new and still evolving. We will largely focus on the nature of carbon nanotubes, buckyballs, grapheme and silver/gold nanoparticles as a means of understanding “nanotech.”

Here’s the week 1 slide deck (revised to reflect the material covered during the class):

Week1_definitions and the nitty grittyR

Here are my ‘notes’ for yesterday’s class consisting largely of brief heads designed to remind me of the content to be found by clicking the link directly after the head.

Week1_definitons and nitty gritty

Happy Reading!

Feathered flight and nanoscale research

Today (Oct. 24, 2014) is a day for flight as I posted this earlier, NASA, super-black nanotechnology, and an International Space Station livestreamed event. With that in mind, here’s an Oct. 23, 2014 news item on Nanowerk about feathers,

Scientists from the University of Southampton [UK] have revealed that feather shafts are made of a multi-layered fibrous composite material, much like carbon fibre, which allows the feather to bend and twist to cope with the stresses of flight.

Since their appearance over 150 million years ago, feather shafts (rachises) have evolved to be some of the lightest, strongest and most fatigue resistant natural structures. However, relatively little work has been done on their morphology, especially from a mechanical perspective and never at the nanoscale.

An Oct. 22, 2014 University of Southampton news release, which originated the news item, describes the study, which may have paleontological implications, in more detail,

The study, which is published by the Royal Society in the journal Interface, is the first to use nano-indentation, a materials testing technique, on feathers. It reveals the number, proportion and relative orientation of rachis layers is not fixed, as previously thought, and varies according to flight style.

Christian Laurent, from Ocean and Earth Science at the University of Southampton, lead author of the study, says: “We started looking at the shape of the rachis and how it changes along the length of it to accommodate different stresses. Then we realised that we had no idea how elastic it was, so we indented some sample feathers.

“Previously, the only mechanical work on feathers was done in the 1970s but under the assumption that the material properties of feathers are the same when tested in different directions, known as isotropic – our work has now invalidated this.”

The researchers tested the material properties of feathers from three birds of different species with markedly different flight styles; the Mute Swan (Cygnus olor), the Bald Eagle (Haliaeetus leucocephalus) and the partridge (Perdix perdix).

Christian, who led the study as part of his research degree (MRes) in Vertebrate Palaeontology, adds: “Our results indicate that the number, and the relative thickness, of layers around the circumference of the rachis and along the feather’s length are not fixed, and may vary either in order to cope with the stresses of flight particular to the bird or to the lineage that the individual belongs to.”

The researchers soon hope to fully model feather functions and link morphological aspects to particular flight styles and lineages, which has several palaeontogical implications and engineering applications.

Christian says: “We hope to be able to scan fossil feathers and finally answer a number of questions – What flew first? Did flight start from the trees down, or from the ground up? Could Archaeopteryx fly? Was Archaeopteryx the first flying bird?

“In terms of engineering, we hope to apply our future findings in materials science to yacht masts and propeller blades, and to apply the aeronautical findings to build better micro air vehicles in a collaboration [with] engineers at the University.”

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

Nanomechanical properties of bird feather rachises: exploring naturally occurring fibre reinforced laminar composites by Christian M. Laurent, Colin Palmer, Richard P. Boardman, Gareth Dyke, and Richard B. Cook. J. R. Soc. [Journal of the Royal Society] Interface 6 December 2014 vol. 11 no. 101 20140961 doi: 10.1098/​rsif.2014.0961  Published 22 October 2014

This is an open access paper.

NASA, super-black nanotechnology, and an International Space Station livestreamed event

A super-black nanotechnology-enabled coating (first mentioned here in a July 18, 2013 posting featuring work by John Hagopian, an optics engineer at the US National Aeronautics and Space Administration [NASA’s] Goddard Space Flight Center on this project) is about to be tested in outer space. From an Oct. 23, 2014 news item on Nanowerk,

An emerging super-black nanotechnology that is to be tested for the first time this fall on the International Space Station will be applied to a complex, 3-D component critical for suppressing stray light in a new, smaller, less-expensive solar coronagraph designed to ultimately fly on the orbiting outpost or as a hosted payload on a commercial satellite.

The super-black carbon-nanotube coating, whose development is six years in the making, is a thin, highly uniform coating of multi-walled nanotubes made of pure carbon about 10,000 times thinner than a strand of human hair. Recently delivered to the International Space Station for testing, the coating is considered especially promising as a technology to reduce stray light, which can overwhelm faint signals that sensitive detectors are supposed to retrieve.

An Oct. 24, 2014 NASA news release by Lori Keesey, which originated the news item, further describes the work being done on the ground simultaneous to the tests on the International Space Station,

While the coating undergoes testing to determine its robustness in space, a team at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, will apply the carbon-nanotube coating to a complex, cylindrically shaped baffle — a component that helps reduce stray light in telescopes.

Goddard optical engineer Qian Gong designed the baffle for a compact solar coronagraph that Principal Investigator Nat Gopalswamy is now developing. The goal is [to] build a solar coronagraph that could deploy on the International Space Station or as a hosted payload on a commercial satellite — a much-needed capability that could guarantee the continuation of important space weather-related measurements.

The effort will help determine whether the carbon nanotubes are as effective as black paint, the current state-of-the-art technology, for absorbing stray light in complex space instruments and components.

Preventing errant light is an especially tricky challenge for Gopalswamy’s team. “We have to have the right optical system and the best baffles going,” said Doug Rabin, a Goddard heliophysicist who studies diffraction and stray light in coronagraphs.

The new compact coronagraph — designed to reduce the mass, volume, and cost of traditional coronagraphs by about 50 percent — will use a single set of lenses, rather than a conventional three-stage system, to image the solar corona, and more particularly, coronal mass ejections (CMEs). These powerful bursts of solar material erupt and hurdle across the solar system, sometimes colliding with Earth’s protective magnetosphere and posing significant hazards to spacecraft and astronauts.

“Compact coronagraphs make greater demands on controlling stray light and diffraction,” Rabin explained, adding that the corona is a million times fainter than the sun’s photosphere. Coating the baffle or occulter with the carbon-nanotube material should improve the component’s overall performance by preventing stray light from reaching the focal plane and contaminating measurements.

The project is well timed and much needed, Rabin added.

Currently, the heliophysics community receives coronagraphic measurements from the Solar and Heliospheric Observatory (SOHO) and the Solar Terrestrial Relations Observatory (STEREO).

“SOHO, which we launched in 1995, is one of our Great Observatories,” Rabin said. “But it won’t last forever.” Although somewhat newer, STEREO has operated in space since 2006. “If one of these systems fails, it will affect a lot of people inside and outside NASA, who study the sun and forecast space weather. Right now, we have no scheduled mission that will carry a solar coronagraph. We would like to get a compact coronagraph up there as soon as possible,” Rabin added.

Ground-based laboratory testing indicates it could be a good fit. Testing has proven that the coating absorbs 99.5 percent of the light in the ultraviolet and visible and 99.8 percent in the longer infrared bands due to the fact that the carbon atoms occupying the tiny nested tubes absorb the light and prevent it from reflecting off surfaces, said Goddard optics engineer John Hagopian, who is leading the technology’s advancement. Because only a tiny fraction of light reflects off the coating, the human eye and sensitive detectors see the material as black — in this case, extremely black.

“We’ve made great progress on the coating,” Hagopian said. “The fact the coatings have survived the trip to the space station already has raised the maturity of the technology to a level that qualifies them for flight use. In many ways the external exposure of the samples on the space station subjects them to a much harsher environment than components will ever see inside of an instrument.”

Given the need for a compact solar coronagraph, Hagopian said he’s especially excited about working with the instrument team. “This is an important instrument-development effort, and, of course, one that could showcase the effectiveness of our technology on 3-D parts,” he said, adding that the lion’s share of his work so far has concentrated on 2-D applications.

By teaming with Goddard technologist Vivek Dwivedi, Hagopian believes the baffle project now is within reach. Dwivedi is advancing a technique called atomic layer deposition (ALD) that lays down a catalyst layer necessary for carbon-nanotube growth on complex, 3-D parts. “Previous ALD chambers could only hold objects a few millimeters high, while the chamber Vivek has developed for us can accommodate objects 20 times bigger; a necessary step for baffles of this type,” Hagopian said.

Other NASA researchers have flown carbon nanotubes on the space station, but their samples were designed for structural applications, not stray-light suppression — a completely different use requiring that the material demonstrate greater absorption properties, Hagopian said.

“We have extreme stray light requirements. Let’s see how this turns out,” Rabin said.

The researchers from NASA have kindly made available an image of a baffle prior to receiving its super-black coating,

This is a close-up view of a baffle that will be coated with a carbon-nanotube coating. Image Credit:  NASA Goddard/Paul Nikulla

This is a close-up view of a baffle that will be coated with a carbon-nanotube coating.
Image Credit: NASA Goddard/Paul Nikulla

There’s more information about the project in this August 12, 2014 NASA news release first announcing the upcoming test.

Serendipitously or not, NASA is hosting an interactive Space Technology Forum on Oct. 27, 2014 (this coming Monday) focusing on technologies being demonstrated on the International Space Station (ISS) according to an Oct. 20, 2014 NASA media advisory,

Media are invited to interact with NASA experts who will answer questions about technologies being demonstrated on the International Space Station (ISS) during “Destination Station: ISS Technology Forum” from 10 to 11 a.m. EDT (9 to 10 a.m. CDT [7 to 8 am PDT]) Monday, Oct. 27, at the U.S. Space & Rocket Center in Huntsville, Alabama.

The forum will be broadcast live on NASA Television and the agency’s website.

The Destination Station forums are a series of live, interactive panel discussions about the space station. This is the second in the series, and it will feature a discussion on how technologies are tested aboard the orbiting laboratory. Thousands of investigations have been performed on the space station, and although they provide benefits to people on Earth, they also prepare NASA to send humans farther into the solar system than ever before.

Forum panelists and exhibits will focus on space station environmental and life support systems; 3-D printing; Space Communications and Navigation (SCaN) systems; and Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES).

The forum’s panelists are:
– Jeffrey Sheehy, senior technologist in NASA’s Space Technology Mission Directorate
– Robyn Gatens, manager for space station System and Technology Demonstration, and Environmental Control Life Support System expert
– Jose Benavides, SPHERES chief engineer
– Rich Reinhart, principal investigator for the SCaN Testbed
– Niki Werkeiser, project manager for the space station 3-D printer

During the forum, questions will be taken from the audience, including media, students and social media participants. Online followers may submit questions via social media using the hashtag, #asknasa. [emphasis mine] …

The “Destination Station: ISS Technology Forum” coincides with the 7th Annual Von Braun Memorial Symposium at the University of Alabama in Huntsville Oct. 27-29. Media can attend the three-day symposium, which features NASA officials, including NASA Administrator Charles Bolden, Associate Administrator for Human Exploration and Operation William Gerstenmaier and Assistant Deputy Associate Administrator for Exploration Systems Development Bill Hill. Jean-Jacques Dordain, director general of the European Space Agency, will be a special guest speaker. Representatives from industry and academia also will be participating.

For NASA TV streaming video, scheduling and downlink information, visit:

http://www.nasa.gov/nasatv

For more information on the International Space Station and its crews, visit:

http://www.nasa.gov/station

I have checked out the livestreaming/tv site and it appears that registration is not required for access. Sadly, I don’t see any the ‘super-black’ coating team members mentioned in the news release on the list of forum participants.

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

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.

Graphene used to create electrodes one atom thick and transparent for brain research applications

It’s usually a ‘John Rogers (at the University of Illinois)’ story when there’s mention of transparent electronic devices but not this time. In an Oct. 20, 2014 news item on ScienceDaily, the University of Pennsylvania’s researchers are in the spotlight,

Researchers from the Perelman School of Medicine and School of Engineering at the University of Pennsylvania and The Children’s Hospital of Philadelphia have used graphene — a two-dimensional form of carbon only one atom thick — to fabricate a new type of microelectrode that solves a major problem for investigators looking to understand the intricate circuitry of the brain.

Pinning down the details of how individual neural circuits operate in epilepsy and other neurological disorders requires real-time observation of their locations, firing patterns, and other factors, using high-resolution optical imaging and electrophysiological recording. But traditional metallic microelectrodes are opaque and block the clinician’s view and create shadows that can obscure important details. In the past, researchers could obtain either high-resolution optical images or electrophysiological data, but not both at the same time.

The Center for NeuroEngineering and Therapeutics (CNT), under the leadership of senior author Brian Litt, PhD, has solved this problem with the development of a completely transparent graphene microelectrode that allows for simultaneous optical imaging and electrophysiological recordings of neural circuits. [emphasis mine] Their work was published this week in Nature Communications.

An Oct. 20, 2014 University of Pennsylvania news release (also on EurekAlert), which originated the news item, further describes the research,

“There are technologies that can give very high spatial resolution such as calcium imaging; there are technologies that can give high temporal resolution, such as electrophysiology, but there’s no single technology that can provide both,” says study co-first-author Duygu Kuzum, PhD. Along with co-author Hajime Takano, PhD, and their colleagues, Kuzum notes that the team developed a neuroelectrode technology based on graphene to achieve high spatial and temporal resolution simultaneously.

Aside from the obvious benefits of its transparency, graphene offers other advantages: “It can act as an anti-corrosive for metal surfaces to eliminate all corrosive electrochemical reactions in tissues,” Kuzum says. “It’s also inherently a low-noise material, which is important in neural recording because we try to get a high signal-to-noise ratio.”

While previous efforts have been made to construct transparent electrodes using indium tin oxide, they are expensive and highly brittle, making that substance ill-suited for microelectrode arrays. “Another advantage of graphene is that it’s flexible, so we can make very thin, flexible electrodes that can hug the neural tissue,” Kuzum notes.

In the study, Litt, Kuzum, and their colleagues performed calcium imaging of hippocampal slices in a rat model with both confocal and two-photon microscopy, while also conducting electrophysiological recordings. On an individual cell level, they were able to observe temporal details of seizures and seizure-like activity with very high resolution. The team also notes that the single-electrode techniques used in the Nature Communications study could be easily adapted to study other larger areas of the brain with more expansive arrays.

The graphene microelectrodes developed could have wider application. “They can be used in any application that we need to record electrical signals, such as cardiac pacemakers or peripheral nervous system stimulators,” says Kuzum. Because of graphene’s nonmagnetic and anti-corrosive properties, these probes “can also be a very promising technology to increase the longevity of neural implants.” Graphene’s nonmagnetic characteristics also allow for safe, artifact-free MRI reading, unlike metallic implants.

Kuzum emphasizes that the transparent graphene microelectrode technology was achieved through an interdisciplinary effort of CNT and the departments of Neuroscience, Pediatrics, and Materials Science at Penn and the division of Neurology at CHOP.

Ertugrul Cubukcu’s lab at Materials Science and Engineering Department helped with the graphene processing technology used in fabricating flexible transparent neural electrodes, as well as performing optical and materials characterization in collaboration with Euijae Shim and Jason Reed. The simultaneous imaging and recording experiments involving calcium imaging with confocal and two photon microscopy was performed at Douglas Coulter’s Lab at CHOP with Hajime Takano. In vivo recording experiments were performed in collaboration with Halvor Juul in Marc Dichter’s Lab. Somatasensory stimulation response experiments were done in collaboration with Timothy Lucas’s Lab, Julius De Vries, and Andrew Richardson.

As the technology is further developed and used, Kuzum and her colleagues expect to gain greater insight into how the physiology of the brain can go awry. “It can provide information on neural circuits, which wasn’t available before, because we didn’t have the technology to probe them,” she says. That information may include the identification of specific marker waveforms of brain electrical activity that can be mapped spatially and temporally to individual neural circuits. “We can also look at other neurological disorders and try to understand the correlation between different neural circuits using this technique,” she says.

It’s fascinating work and I hope it’s helpful but I can’t help noticing that these researchers, in common with most, tend to view the brain or whatever body part they’re examining in isolation from the rest of the body, whatever species is being examined. The answers as to why there are brain disorders and diseases may not lie wholly within the brain itself but within the totality of the organism in which the brain resides, i.e., the body. That reservation aside, there’s a link to and a citation for the research paper,

Transparent and flexible low noise graphene electrodes for simultaneous electrophysiology and neuroimaging by Duygu Kuzum, Hajime Takano, Euijae Shim, Jason C. Reed, Halvor Juul, Andrew G. Richardson, Julius de Vries, Hank Bink, Marc A. Dichter, Timothy H. Lucas, Douglas A. Coulter, Ertugrul Cubukcu, & Brian Litt. Nature Communications 5, Article number: 5259 doi:10.1038/ncomms6259 Published 20 October 2014

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

‘Genius’ grant (MacArthur Fellowship) for reseacher Mark Hersam and his work on carbon nanotubes and the next generation of electronics

It took a few minutes to figure out why Mark Hersam, professor at Northwestern University (Chicago, Illinois, US) is being featured in an Oct. 21, 2014 news item on Nanowerk,

One of the longstanding problems of working with nanomaterials–substances at the molecular and atomic scale–is controlling their size. When their size changes, their properties also change. This suggests that uniform control over size is critical in order to use them reliably as components in electronics.

Put another way, “if you don’t control size, you will have inhomogeneity in performance,” says Mark Hersam. “You don’t want some of your cell phones to work, and others not.”

Hersam, a professor of materials science engineering, chemistry and medicine at Northwestern University, has developed a method to separate nanomaterials by size, therefore providing a consistency in properties otherwise not available. Moreover, the solution came straight from the life sciences–biochemistry, in fact.

The technique, known as density gradient ultracentrifugation, is a decades-old process used to separate biomolecules. The National Science Foundation (NSF)-funded scientist theorized correctly that he could adapt it to separate carbon nanotubes, rolled sheets of graphene (a single atomic layer of hexagonally bonded carbon atoms), long recognized for their potential applications in computers and tablets, smart phones and other portable devices, photovoltaics, batteries and bioimaging.

The technique has proved so successful that Hersam and his team now hold two dozen pending or issued patents, and in 2007 established their own company, NanoIntegris, jump-started with a $150,000 NSF small business grant. The company has been able to scale up production by 10,000-fold, and currently has 700 customers in 40 countries.
“We now have the capacity to produce ten times the worldwide demand for this material,” Hersam says.

NSF supports Hersam with a $640,000 individual investigator grant awarded in 2010 for five years. Also, he directs Northwestern’s Materials Research Science and Engineering Center (MRSEC), which NSF funds, including support for approximately 30 faculty members/researchers.

Hersam also is a recent recipient of one of this year’s prestigious MacArthur fellowships, a $625,000 no-strings-attached award, popularly known as a “genius” grant. [emphases mine] These go to talented individuals who have shown extraordinary originality and dedication in their fields, and are meant to encourage beneficiaries to freely explore their interests without fear of risk-taking.

An Oct. 20, 2014 US National Science Foundation Discoveries article by Marlene Cimons, which originated the news item, describes Hersam’s research and his hopes for it in more detail,

The carbon nanotubes separation process, which Hersam developed, begins with a centrifuge tube. Into that, “we load a water based solution and introduce an additive which allows us to tune the buoyant density of the solution itself,” he explains.

“What we create is a gradient in the buoyant density of the aqueous solution, with low density at the top and high density at the bottom,” he continues. “We then load the carbon nanotubes and put it into the centrifuge, which drives the nanotubes through the gradient. The nanotubes move through the gradient until their density matches that of the gradient. The result is that the nanotubes form separated bands in the centrifuge tube by density. Since the density of the nanotube is a function of its diameter, this method allows separation by diameter.”

One property that distinguishes these materials from traditional semiconductors like silicon is that they are mechanically flexible. “Carbon nanotubes are highly resilient,” Hersam says. “That allows us to integrate electronics on flexible substrates, like clothing, shoes, and wrist bands for real time monitoring of biomedical diagnostics and athletic performance. These materials have the right combination of properties to realize wearable electronics.”

He and his colleagues also are working on energy technologies, such as solar cells and batteries “that can improve efficiency and reduce the cost of solar cells, and increase the capacity and reduce the charging time of batteries,” he says. “The resulting batteries and solar cells are also mechanically flexible, and thus can be integrated with flexible electronics.”

They likely even will prove waterproof. “It turns out that carbon nanomaterials are hydrophobic, so water will roll right off of them,” he says.

A Sept. 17, 2014 Northwestern University news release congratulates Hersam on his award while describing his response to the news and providing more information about his work as a researcher and teacher (Note: Links have been removed),

The phone call from the John D. and Catherine T. MacArthur Foundation delivering the very good news was so out of the blue that Hersam initially thought it was a joke.

“Then I went into shock, and, I think, to some extent I remain in shock,” said Hersam, who received the call in his Cook Hall office. “As time has gone on, I’ve appreciated, of course, that it’s a great honor and, more importantly, a great opportunity.”

A dedicated and popular teacher, Hersam is the Bette and Neison Harris Chair in Teaching Excellence and professor of materials science and engineering at the McCormick School of Engineering and Applied Science.

“There are very few awards that provide unrestricted resources, and this one does. No strings attached,” he said. “That’s a great opportunity for a researcher — to have that level of freedom.”

Hersam is one of 21 new MacArthur Fellows recognized today (Sept. 17) by the MacArthur Foundation for “extraordinary originality and dedication in their creative pursuits and a marked capacity for self-direction.”

“I am very grateful and thankful to the MacArthur Foundation, to current and previous members of my research group and to my colleagues and collaborators over the years,” Hersam said. “Scientific research is a team effort.”

Hersam views his principal job as that of an educator — a role in which he can have more impact on unsolved problems by harnessing the minds of hundreds of young scientists and engineers.

“I love to teach in the classroom, but I also believe that scientific research is a vehicle for teaching,” Hersam said. “Research exposes students to difficult unsolved problems, forcing them to be creative. I want them to come up with truly new ideas, not just regurgitate established concepts.”

Hersam, who joined Northwestern in 2000, also is professor of chemistry in the Weinberg College of Arts and Sciences, professor of medicine at the Northwestern University Feinberg School of Medicine and director of Northwestern’s Materials Research Center.

Taking an interdisciplinary approach that draws on techniques from materials science, physics, engineering and chemistry, Hersam has established himself as a leading experimentalist in the area of hybrid organic-inorganic materials, with a focus on the study of the electrical and optical properties of carbon and related nanomaterials.

Hersam and his research lab have been working primarily with carbon nanotubes and graphene, but the support of the MacArthur award will allow the lab to diversify its materials set to other elements in the periodic table.

Earlier this year Hersam testified before U.S. Congress to push for “coordinated, predictable and sustained federal funding” for nanotechnology research and development.

The MacArthur Foundation’s website hosts a video on its ‘Mark Hersam’ webpage,

Interestingly, Hersam, in the video, describes a carbon nanotube as a rolled up sheet of graphene (it’s also described that way on the Foundation’s ‘Hersam’ webpage),

Graphene, a single atomic layer of hexagonally bonded carbon atoms, and carbon nanotubes, rolled sheets of graphene in single or multiple layers, have long been recognized for their potential applications in electronics, photovoltaics, batteries, and bioimaging.

It’s a good way of describing carbon nanotubes but the odd thing is that carbon nanotubes were discovered in 1991 (Timeline of carbon nanotubes entry on Wikipedia and in The History of Carbon Nanotubes on nanogloss.com) before graphene was first isolated in 2004 (my Oct. 7, 2010 posting).

Getting up to the size of a dust speck, the first ‘large’ self-assembling DNA crystals

An Oct. 19, 2014 news item on ScienceDaily describes the latest developments in ‘DNA nanotechnology’ research at the Wyss Institute for Biologically Inspired Engineering at Harvard University,

DNA has garnered attention for its potential as a programmable material platform that could spawn entire new and revolutionary nanodevices in computer science, microscopy, biology, and more. Researchers have been working to master the ability to coax DNA molecules to self assemble into the precise shapes and sizes needed in order to fully realize these nanotechnology dreams.

For the last 20 years, scientists have tried to design large DNA crystals with precisely prescribed depth and complex features — a design quest just fulfilled by a team at Harvard’s Wyss Institute for Biologically Inspired Engineering. The team built 32 DNA crystals with precisely-defined depth and an assortment of sophisticated three-dimensional (3D) features, an advance reported in Nature Chemistry.

It seems a bit of a misleading for the Wyss Institute to state the ‘team built’ the DNA crystals as they are self-assembling according to this Oct. 19, 2014 Wyss Institute news release (also on EurekAlert), which originated the news item,

The team used their “DNA-brick self-assembly” method, which was first unveiled in a 2012 Science publication when they created more than 100 3D complex nanostructures about the size of viruses. The newly-achieved periodic crystal structures are more than 1000 times larger than those discrete DNA brick structures, sizing up closer to a speck of dust, which is actually quite large in the world of DNA nanotechnology.

“We are very pleased that our DNA brick approach has solved this challenge,” said senior author and Wyss Institute Core Faculty member Peng Yin, Ph.D., who is also an Associate Professor of Systems Biology at Harvard Medical School, “and we were actually surprised by how well it works.”

The news release goes on to describe some of the issues with other self-assembly methods along with more details about the ‘DNA brick’ approach,

Scientists have struggled to crystallize complex 3D DNA nanostructures using more conventional self-assembly methods. The risk of error tends to increase with the complexity of the structural repeating units and the size of the DNA crystal to be assembled.

The DNA brick method uses short, synthetic strands of DNA that work like interlocking Lego® bricks to build complex structures. Structures are first designed using a computer model of a molecular cube, which becomes a master canvas. Each brick is added or removed independently from the 3D master canvas to arrive at the desired shape – and then the design is put into action: the DNA strands that would match up to achieve the desired structure are mixed together and self assemble to achieve the designed crystal structures.

“Therein lies the key distinguishing feature of our design strategy—its modularity,” said co-lead author Yonggang Ke, Ph.D., formerly a Wyss Institute Postdoctoral Fellow and now an assistant professor at the Georgia Institute of Technology and Emory University. “The ability to simply add or remove pieces from the master canvas makes it easy to create virtually any design.”

The modularity also makes it relatively easy to precisely define the crystal depth. “This is the first time anyone has demonstrated the ability to rationally design crystal depth with nanometer precision, up to 80 nm in this study,” Ke said. In contrast, previous two-dimensional DNA lattices are typically single-layer structures with only 2 nm depth.

“DNA crystals are attractive for nanotechnology applications because they are comprised of repeating structural units that provide an ideal template for scalable design features”, said co-lead author graduate student Luvena Ong.

Furthermore, as part of this study the team demonstrated the ability to position gold nanoparticles into prescribed 2D architectures less than two nanometers apart from each other along the crystal structure – a critical feature for future quantum devices and a significant technical advance for their scalable production, said co-lead author Wei Sun, Ph.D., Wyss Institute Postdoctoral Fellow.

“My preconceived notions of the limitations of DNA have been consistently shattered by our new advances in DNA nanotechnology,” said William Shih, Ph.D., who is co-author of the study and a Wyss Institute Founding Core Faculty member, as well as Associate Professor in the Department of Biological Chemistry and Molecular Pharmacology at Harvard Medical School and the Department of Cancer Biology at the Dana-Farber Cancer Institute. “DNA nanotechnology now makes it possible for us to assemble, in a programmable way, prescribed structures rivaling the complexity of many molecular machines we see in Nature.”

“Peng’s team is using the DNA-brick self-assembly method to build the foundation for the new landscape of DNA nanotechnology at an impressive pace,” said Wyss Institute Founding Director Don Ingber, M.D., Ph.D. “What have been mere visions of how the DNA molecule could be used to advance everything from the semiconductor industry to biophysics are fast becoming realities.”

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

DNA brick crystals with prescribed depths by Yonggang Ke, Luvena L. Ong, Wei Sun, Jie Song, Mingdong Dong, William M. Shih, & Peng Yin. Nature Chemistry (2014) doi:10.1038/nchem.2083 Published online 19 October 2014

This paper is behind a paywall.

Simon Fraser University – Bioelectronics course: Week 6 (the end)

As I noted in my Oct. 7, 2014 posting, I changed up the order of the classes. Last night (Oct. 20, 2014)), I presented the Week 5 material for the last class  of Bioelectronics, Medical Imaging and Our Bodies (at Simon Fraser University in Vancouver, Canada). So, here’s a description of what I presented in this course’s last class,

Week 5 6: Reverse Engineering the Brain and Neuromorphic Engineering

New computer algorithms exploit supercomputing architectures in order to measure the connections between cortical and sub-cortical locations in the human body. While brain repair is one desired outcome, there is also a major interest in developing artificial brains. The boundary between machine and human is breaking down.

I also presented information about the ‘brain in a dish’ mentioned in the session on Growing Human Organs.

Here’s the final week’s slide deck,

Week 5_Reverse & Neuromorphic Engineering

As usual, here are my ‘notes’ for last night’s class consisting largely of brief heads designed to remind me of the content to be found by clicking the link directly after the head.

Week 5 Neuromorphic engineering and brain

Happy Reading! and one final note, I will be teaching a new six-week course at Simon Fraser University : Nanotechnology: The Next Big Idea.  It starts this week on Thursday, Oct. 23, 2014.

Like a starfish shell, facetless crystals

Made by accident, these facetless crystals could prove useful in applications for cells, medications, and more according to researchers at the University of Michigan in an Oct. 20, 2014 news item on Nanowerk,

In a design that mimics a hard-to-duplicate texture of starfish shells, University of Michigan engineers have made rounded crystals that have no facets.

“We call them nanolobes. They look like little hot air balloons that are rising from the surface,” said Olga Shalev, a doctoral student in materials science and engineering who worked on the project.

There is a video with the researcher, Olga Shalev, describing the nanolobes in more detail,

An Oct. 17, 2014 University of Michigan news release (also on EurekAlert*), which originated the news item, offers text for those who prefer to read about the science rather than receive it by video,

Both the nanolobes’ shape and the way they’re made have promising applications, the researchers say. The geometry could potentially be useful to guide light in advanced LEDs, solar cells and nonreflective surfaces. A layer might help a material repel water or dirt. And the process used to manufacture them – organic vapor jet printing – might lend itself to 3D-printing medications that absorb better into the body and make personalized dosing possible.

The nanoscale shapes are made out of boron subphthalocyanine chloride, a material often used in organic solar cells. It’s in a family of small molecular compounds that tend to make either flat films or faceted crystals with sharp edges, says Max Shtein, an associate professor of materials science and engineering, macromolecular science and engineering, chemical engineering, and art and design.

“In my years of working with these kinds of materials, I’ve never seen shapes that looked like these. They’re reminiscent of what you get from biological processes,” Shtein said. “Nature can sometimes produce crystals that are smooth, but engineers haven’t been able to do it reliably.”

Echinoderm sea creatures such as brittle stars have ordered rounded structures on their bodies that work as lenses to gather light into their rudimentary eyes. But in a lab, crystals composed of the same minerals tend either to be faceted with flat faces and sharp angles, or smooth, but lacking molecular order.

The U-M researchers made the curved crystals by accident several years ago. They’ve since traced their steps and figured out how to do it on purpose.

In 2010, Shaurjo Biswas, then a doctoral student at U-M, was making solar cells with the organic vapor jet printer. He was recalibrating the machine after switching between materials. Part of the recalibration process involves taking a close look at the fresh layers of material, of films, printed on a plate. Biswas X-rayed several films of different thicknesses to observe the crystal structure. He noticed that the boron subphthalocyanine chloride, which typically does not form ordered shapes, started to do so once the film got thicker than 600 nanometers. He made some thicker films to see what would happen.

“At first, we wondered if our apparatus was functioning properly,” Shtein said.

At 800 nanometers thick, the repeating nanolobe pattern emerged every time.

For a long while, the blobs were lab curiosities. Researchers were focused on other things. Then doctoral student Shalev got involved. She was fascinated by the structures and wanted to understand the reason for the phenomenon. She repeated the experiments in a modified apparatus that gave more control over the conditions to vary them systematically. She collaborated with physics professor Roy Clarke to gain a better understanding of the crystallization, and mechanical engineering professor Wei Lu to simulate the evolution of the surface.. She’s first author of a paper on the findings published in the current edition of Nature Communications.

“As far as we know, no other technology can do this,” Shalev said.

The organic vapor jet printing process the researchers use is a technique Shtein helped to develop when he was in graduate school. He describes it as spray painting, but with a gas rather than with a liquid. It’s cheaper and easier to do for certain applications than competing approaches that involve stencils or can only be done in a vacuum, Shtein says. He’s especially hopeful about the prospects for this technique to advance emerging 3D-printed pharmaceutical concepts.

For example, Shtein and Shalev believe this method offers a precise way to control the size and shape of the medicine particles, for easier absorption into the body. It could also allow drugs to be attached directly to other materials and it doesn’t require solvents that might introduce impurities.

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

Growth and modelling of spherical crystalline morphologies of molecular materials by O. Shalev, S. Biswas, Y. Yang, T. Eddir, W. Lu, R. Clarke,  & M. Shtein. Nature Communications 5, Article number: 5204 doi:10.1038/ncomms6204 Published 16 October 2014

This paper is behind a paywall.

* EurekAlert link added on Oct. 20, 2014 at 1035 hours PDT.

Heart of stone

Researchers in Europe do not want to find out what would Europe look like without its stone castles, Stonehenge, Coliseum, cathedrals, and other monumental stone structures, and have found a possible solution to the problem of deterioration according to an Oct. 20, 2014 news item on Nanowerk,

Castles and cathedrals, statues and spires… Europe’s built environment would not be the same without these witnesses of centuries past. But, eventually, even the hardest stone will crumble. EU-funded researchers have developed innovative nanomaterials to improve the preservation of our architectural heritage.

“Our objective,” says Professor Gerald Ziegenbalg of IBZ Salzchemie, “was to find new possibilities to consolidate stone and mortar, especially in historical buildings.” The products available at the time, he adds, didn’t meet the full range of requirements, and some could actually damage the artefacts they were meant to preserve. Alternatives compatible with the original materials were needed.

A July 9, 2014 European Commission press release, which originated the news item, provides more details about this project (Note: A link has been removed),

 Ziegenbalg was the coordinator of the Stonecore project, which rose to this monumental challenge within a mere three years. It developed and commercialised a new type of material that penetrates right into the stone, protecting it without any risk of damage or harmful residues. The team also invented new ways to assess damage to stone and refined a number of existing techniques.

The concept behind the new material developed by the Stonecore partners is ingenious. It involves lime nanoparticles suspended in alcohol, a substance that evaporates completely upon exposure to air. The nanoparticles then react with carbon dioxide in the atmosphere to form limestone.

This innovation is on the market under the brand name CaLoSil. It is available in various consistencies – liquids and pastes – and in a number of formulations based on different types of alcohol, as well as with added filler materials such as marble. The product is applied by dipping, spraying or injection into the stone.

Beyond its use as a consolidant, CaLoSil can also be used to clean stone and mortar, as it helps to treat fungus and algae. The dehydrating effect of the alcohol and the acidity of the lime destroy the cells, and the growth can then be washed off. This method, says Ziegenbalg, is more effective than conventional chemical or mechanical approaches, and it does not damage the stone.

Limestone face-lifts

The partners tested their new product in a number of locations across Europe, on a wide variety of materials exposed to very different conditions. Together, they rejuvenated statues and sculptures, saved features in cathedrals and citadels, and treated materials as diverse as sandstone, marble and tuff.

The opportunity to access such a wide variety of sites, says Ziegenbalg, was one of the many advantages of working with partners from several countries. It pre-empted the risk of developing a product that was too narrowly focused on a specific application.

Inside the heart of stone

A number of techniques enable conservation teams to assess the state of the objects in their care. To obtain a clearer picture of deeper damage, Stonecore improved existing approaches involving ultrasound, developing a new device. The project also pioneered a new technique based on ground-penetrating radar, which one partner is now offering as a commercial service.

The team also developed an innovative micro-drilling tool and refined an existing technique for measuring the water uptake of stone.

A further innovation is a new technique to measure surface degradation. For this so-called “peeling test”, a length of adhesive tape is affixed to the object. The weight of the particles that come off with the tape when it is removed indicate how likely the stone is to degrade.

Carving out solutions

The partners’ achievements have not gone unnoticed. In 2013, Stonecore was shortlisted along with 10 other projects for the annual EuroNanoForum’s Best Project Award.

Ziegenbalg attributes the team’s success mainly to the partners’ wide range of complementary expertise, and to their dedication. “The participating small and medium-sized enterprises were extremely active,” he says. “They were highly motivated to handle the more practical work, while the universities supported them with the necessary research input.”

While it’s not clear from this press release or the Stonecore website, it appears this project has run its course as part of European Union’s Framework Programme 7.