Tag Archives: Harvard University

Let’s make our turbine blades really big (greater than 75 metres) with new nanocomposite

The is a story about balsa wood, wind farms, turbine blades, and nanocomposites according to a June 25, 2014 news item on ScienceDaily,

In wind farms across North America and Europe, sleek turbines equipped with state-of-the-art technology convert wind energy into electric power. But tucked inside the blades of these feats of modern engineering is a decidedly low-tech core material: balsa wood.

Like other manufactured products that use sandwich panel construction to achieve a combination of light weight and strength, turbine blades contain carefully arrayed strips of balsa wood from Ecuador, which provides 95 percent of the world’s supply.

For centuries, the fast-growing balsa tree has been prized for its light weight and stiffness relative to density. But balsa wood is expensive and natural variations in the grain can be an impediment to achieving the increasingly precise performance requirements of turbine blades and other sophisticated applications.

As turbine makers produce ever-larger blades — the longest now measure 75 meters, almost matching the wingspan of an Airbus A380 jetliner — they must be engineered to operate virtually maintenance-free for decades. In order to meet more demanding specifications for precision, weight, and quality consistency, manufacturers are searching for new sandwich construction material options.

Now, using a cocktail of fiber-reinforced epoxy-based thermosetting resins and 3D extrusion printing techniques, materials scientists at the Harvard School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering have developed cellular composite materials of unprecedented light weight and stiffness.

A June 25, 2014 Harvard University news release (also on EurekAlert), which originated the news item, goes on to describe the new technology in more detail while throwing 3D printing into the mix,

Until now, 3D printing has been developed for thermo plastics and UV-curable resins—materials that are not typically considered as engineering solutions for structural applications. “By moving into new classes of materials like epoxies, we open up new avenues for using 3D printing to construct lightweight architectures,” says principal investigator Jennifer A. Lewis, the Hansjörg Wyss Professor of Biologically Inspired Engineering at Harvard SEAS. “Essentially, we are broadening the materials palate for 3D printing.”

“Balsa wood has a cellular architecture that minimizes its weight since most of the space is empty and only the cell walls carry the load. It therefore has a high specific stiffness and strength,” explains Lewis, who in addition to her role at Harvard SEAS is also a Core Faculty Member at the Wyss Institute. “We’ve borrowed this design concept and mimicked it in an engineered composite.”

Lewis and Brett G. Compton, a former postdoctoral fellow in her group, developed inks of epoxy resins, spiked with viscosity-enhancing nanoclay platelets and a compound called dimethyl methylphosphonate, and then added two types of fillers: tiny silicon carbide “whiskers” and discrete carbon fibers. Key to the versatility of the resulting fiber-filled inks is the ability to control the orientation of the fillers.

The direction that the fillers are deposited controls the strength of the materials (think of the ease of splitting a piece of firewood lengthwise versus the relative difficulty of chopping on the perpendicular against the grain).

Lewis and Compton have shown that their technique yields cellular composites that are as stiff as wood, 10 to 20 times stiffer than commercial 3D-printed polymers, and twice as strong as the best printed polymer composites. The ability to control the alignment of the fillers means that fabricators can digitally integrate the composition, stiffness, and toughness of an object with its design.

“This paper demonstrates, for the first time, 3D printing of honeycombs with fiber-reinforced cell walls,” said Lorna Gibson, a professor of materials science and mechanical engineering at the Massachusetts Institute of Technology and one of world’s leading experts in cellular composites, who was not involved in this research. “Of particular significance is the way that the fibers can be aligned, through control of the fiber aspect ratio—the length relative to the diameter—and the nozzle diameter. This marks an important step forward in designing engineering materials that mimic wood, long known for its remarkable mechanical properties for its weight.”

“As we gain additional levels of control in filler alignment and learn how to better integrate that orientation into component design, we can further optimize component design and improve materials efficiency,” adds Compton, who is now a staff scientist in additive manufacturing at Oak Ridge National Laboratory. “Eventually, we will be able to use 3D printing technology to change the degree of fiber filler alignment and local composition on the fly.”

The work could have applications in many fields, including the automotive industry where lighter materials hold the key to achieving aggressive government-mandated fuel economy standards. According to one estimate, shedding 110 pounds from each of the 1 billion cars on the road worldwide could produce $40 billion in annual fuel savings.

3D printing has the potential to radically change manufacturing in other ways too. Lewis says the next step will be to test the use of thermosetting resins to create different kinds of architectures, especially by exploiting the technique of blending fillers and precisely aligning them. This could lead to advances not only in structural materials, but also in conductive composites.

Previously, Lewis has conducted groundbreaking research in the 3D printing of tissue constructs with vasculature and lithium-ion microbatteries.

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

3D-Printing of Lightweight Cellular Composites by Brett G. Compton and Jennifer A. Lewis. Advanced Materials DOI: 10.1002/adma.201401804 Article first published online: 18 JUN 2014

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

This paper is behind a paywall.

Smelling Paris in New York (update on the oPhone)

The American Museum of Natural History in New York was the recipient of the world’s first (?) transatlantic oPhone transmission on Tuesday, June 17, 2014. Linda Tischler provides an account of the event in her June 17, 2014 article about the latest on the oPhone for Fast Company (Note: Links have been removed),

At 11:31 EDT on Tuesday [June 17, 2014], an email message encoded with the scent of Paris, winged its way across the ether to land in the inbox of a Harvard professor waiting eagerly in a skull-littered basement room in New York’s American Museum of Natural History.

The onote, as such scent-embedded mail is known–originated at Le Laboratoire in Paris as a picture of a plate of macaroons and a glass of champagne, and was tagged via an iPhone app called oSnap, with the elements–tropical fruit, cocoa beans and champagne–that comprised their aroma.

messages [sic]–the aroma was, well, undeniably smelly, if a tad muddled. A hint of chocolate was there; something sort of fruity came through; the champagne would have been hard to detect without knowing what to smell for. Did it evoke wine and cookies? Not really. But, to its credit, the gadget worked.

“When you play all three scents at once, it’s sometimes hard to determine what you’re smelling,” says David Edwards, Harvard professor of idea translation and co-inventor of the device with Rachel Field, a former Harvard student.

I first mentioned David Edwards and Rachel Field along with their oPhone project in a Feb. 14, 2014 posting, which describes preliminary testing in Paris and provides links to a research paper. It seems there’s been good progress since then as the American Museum of Natural History is now preparing to host three oPhone hotspot weekends in July 2014 as Tischler notes in her article,

While potential users can currently download the app for free from the Apple app store, there’s no way yet for them to play their aromatic missives without going to an oPhone-equipped hotspot. Starting on July 12 [2014], and continuing for three consecutive weekends, the museum will host a hotspot in New York where people can come and retrieve the onotes they’ve been sent. There will be other hotspots in Paris and Cambridge, with more to come.

Since tagging photos with scent is a skill that few people have yet mastered, the museum will also host free “scent adventures,” where an olefactorially-skilled expert — a chef, a coffee connoisseur, or a chocolatier, for example — will coach aroma newbies in how to compose a scent that resembles what they’re smelling. The app itself comes with a vocabulary of “notes”–green vegetation, grilled bread, onion, jasmine, cedar, for example–that allows users to compose more than 300,000 different scents.

Weirdly, the American Natural History Museum’s June 17, 2014 news release about the oPhone and the upcoming ‘scent’ weekends provides less detail,

For three consecutive weekends starting on July 12 [2014], the Museum will feature an oPhone in its Sackler Educational Laboratory for Comparative Genomics and Human Origins, where visitors can try the technology and learn about how smell is processed in humans compared to our primate and hominid relatives.

It seems the museum’s weekend oPhone hotspot events came together very quickly since they are not yet (as of June 18, 2014 at 0930 hours PDT) listed in the museum’s July 2014 calendar of events.

A June 18, 2014 Harvard University news release by Alvin Powell provides some detail about the latest physical configuration for the oPhone,

The oPhone system consists of several parts. It begins with the oSnap app for iPhones (an android version is in development) that allows a user to create an oNote, consisting of a photograph and a smell created out of a palette of 32 scents available in the app that can be combined in 300,000 possible combinations.

The sender then forwards the oNote to an oPhone — the hardware portion of the enterprise — which re-creates the aroma from the oSnap app. The key component of the oPhone is the oChip, which creates the actual smell.

The oPhone looks a bit like a desk telephone, only instead of a handset, it has two small hollow towers — from which the newly created scents emerge — extending from the top.

In the hopes of making their oPhone more available the researchers and inventors have instituted an indiegogo crowdfunding campaign, oPhone Duo; bringing scent to mobile messaging,

There is a special offer which expires 12 pm (noon; 1200 hours) Paris time on June 19, 2014,

 $149 USD

LIMITED TIME OFFER – If you choose this perk between now and 12pm on June 19th Paris time, we will throw in an EXTRA PACK OF CUSTOM OCHIPS FOR FREE!!! Be among the first to buy an oPhone DUO. We’ll include one pack of oChips (replaceable aroma cartridges) that support two of our first aromatic vocabularies to get you started. What you get: 1 oPhone DUO 1 pack of Foodie I.D. oChips 1 pack of Base Notes oChips FREE SHIPPING

In two days (campaign opened June 16, 2014), they have raised $7800 towards a goal of $150,000 and a campaign deadline of July 31, 2014.

Good luck!

Computerized cockroaches as precursors to new healing techniques

The last time I wrote about cockroaches was in a June 26, 2013 posting about cyborg cockroaches and neuroscience. This latest cockroach item, which concerns new therapeutic approaches, comes from an April 8, 2014 article by Sarah Spickernell for New Scientist (Note: A link has been removed),

It’s a computer – inside a cockroach. Nano-sized entities made of DNA that are able to perform the same kind of logic operations as a silicon-based computer have been introduced into a living animal.

The DNA computers – known as origami robots because they work by folding and unfolding strands of DNA – travel around the insect’s body and interact with each other, as well as the insect’s cells. When they uncurl, they can dispense drugs carried in their folds.

“DNA nanorobots could potentially carry out complex programs that could one day be used to diagnose or treat diseases with unprecedented sophistication,” says Daniel Levner, a bioengineer at the Wyss Institute at Harvard University.

Levner and his colleagues at Bar Ilan University in Ramat-Gan, Israel, made the nanobots by exploiting the binding properties of DNA. When it meets a certain kind of protein, DNA unravels into two complementary strands. By creating particular sequences, the strands can be made to unravel on contact with specific molecules – say, those on a diseased cell. When the molecule unravels, out drops the package wrapped inside.

Spickernell’s description of the researchers’ plan to increase the amount of computing power in a cockroach to the equivalent of an eight-bit computer seems eye-opening until you read about their plans for preliminary human clinical trials using the same technique for mammals as they have in insects.

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

Universal computing by DNA origami robots in a living animal by Yaniv Amir, Eldad Ben-Ishay, Daniel Levner, Shmulik Ittah, Almogit Abu-Horowitz, & Ido Bachelet. Nature Nanotechnology (2014) doi:10.1038/nnano.2014.58 Published online 06 April 2014

The paper is behind a paywall but there is an option for a free preview via ReadCube access.

Mesenchymal condensation (a process embryos use to begin forming a variety of organs, including teeth, cartilage, bone, muscle, tendon, and kidney) for complex 3D tissue engineering

It seems that there are three strategies for creating complex 3D tissues and until now scientists have used only two of the three. From a March 5, 2014 news item on ScienceDaily,

A bit of pressure from a new shrinking, sponge-like gel is all it takes to turn transplanted unspecialized cells into cells that lay down minerals and begin to form teeth.

The bioinspired gel material could one day help repair or replace damaged organs, such as teeth and bone, and possibly other organs as well, scientists from the Wyss Institute for Biologically Inspired Engineering at Harvard University, Harvard School of Engineering and Applied Sciences (SEAS), and Boston Children’s Hospital report recently in Advanced Materials.

“Tissue engineers have long raised the idea of using synthetic materials to mimic the inductive power of the embryo,” said Don Ingber, M.D., Ph.D., Founding Director of the Wyss Institute, …, Professor of Bioengineering at SEAS, and senior author of the study. “We’re excited about this work because it shows that it really is possible.”

The March 5, 2014 Wyss Institute news release, which originated the news item, delves into the nature of the research,

Embryonic tissues have the power to drive cells and tissues to specialize and form organs. To do that, they employ biomolecules called growth factors to stimulate growth; gene-activating chemicals that cause the cells to specialize, and mechanical forces that modulate cell responses to these other factors.

But so far tissue engineers who want to build organs in the laboratory have employed only two of the three strategies — growth factors and gene-activating chemicals. Perhaps as a result, they have not yet succeeded in producing complex three-dimensional tissues.

A few years ago, Ingber and Tadanori Mammoto, M.D., Ph.D., Instructor in Surgery at Boston Children’s Hospital and Harvard Medical School, investigated a process called mesenchymal condensation that embryos use to begin forming a variety of organs, including teeth, cartilage, bone, muscle, tendon, and kidney.

In mesenchymal condensation, two adjacent tissue layers — loosely packed connective-tissue cells called mesenchyme and sheet-like tissue called an epithelium that covers it — exchange biochemical signals. This exchange causes the mesenchymal cells to squeeze themselves tightly into a small knot directly below where the new organ will form.

Here’s a video from the Wyss Institute illustrating the squeezing process,

When the temperature rises to just below body temperature, this biocompatible gel shrinks dramatically within minutes, bringing tooth-precursor cells (green) closer together. Credit: Basma Hashmi

Getting back to the research (from the news release),

By examining tissues isolated from the jaws of embryonic mice, Mammoto and Ingber showed that when the compressed mesenchymal cells turn on genes that stimulate them to generate whole teeth composed of mineralized tissues, including dentin and enamel.

Inspired by this embryonic induction mechanism, Ingber and Basma Hashmi, a Ph.D. candidate at SEAS who is the lead author of the current paper, set out to develop a way to engineer artificial teeth by creating a tissue-friendly material that accomplishes the same goal. Specifically, they wanted a porous sponge-like gel that could be impregnated with mesenchymal cells, then, when implanted into the body, induced to shrink in 3D to physically compact the cells inside it.

To develop such a material, Ingber and Hashmi teamed up with researchers led by Joanna Aizenberg, Ph.D., a Wyss Institute Core Faculty member who leads the Institute’s Adaptive Materials Technologies platform. Aizenberg is the Amy Smith Berylson Professor of Materials Science at SEAS and Professor of Chemistry and Chemical Biology at Harvard University.

They chemically modified a special gel-forming polymer called PNIPAAm that scientists have used to deliver drugs to the body’s tissues. PNIPAAm gels have an unusual property: they contract abruptly when they warm.

But they do this at a lukewarm temperature, whereas the researchers wanted them to shrink specifically at 37°C — body temperature — so that they’d squeeze their contents as soon as they were injected into the body. Hashmi worked with Lauren Zarzar, Ph.D., a former SEAS graduate student who’s now a postdoctoral associate at Massachusetts Institute of Technology, for more than a year, modifying PNIPAAm and testing the resulting materials. Ultimately, they developed a polymer that forms a tissue-friendly gel with two key properties: cells stick to it, and it compresses abruptly when warmed to body temperature.

As an initial test, Hashmi implanted mesenchymal cells in the gel and warmed it in the lab. Sure enough, when the temperature reached 37°C, the gel shrank within 15 minutes, causing the cells inside the gel to round up, shrink, and pack tightly together.

“The reason that’s cool is that the cells are alive,” Hashmi said. “Usually when this happens, cells are dead or dying.”

Not only were they alive — they activated three genes that drive tooth formation.

To see if the shrinking gel also worked its magic in the body, Hashmi worked with Mammoto to load mesenchymal cells into the gel, then implant the gel beneath the mouse kidney capsule — a tissue that is well supplied with blood and often used for transplantation experiments.

The implanted cells not only expressed tooth-development genes — they laid down calcium and minerals, just as mesenchymal cells do in the body as they begin to form teeth.

“They were in full-throttle tooth-development mode,” Hashmi said.

The researchers have future plans (from the news release),

In the embryo, mesenchymal cells can’t build teeth alone — they need to be combined with cells that form the epithelium. In the future, the scientists plan to test whether the shrinking gel can stimulate both tissues to generate an entire functional tooth.

Here’s a link to and a citation for the paper about the successful attempt to stimulate mesenchymal cells into the beginnings of tooth formation,

Developmentally-Inspired Shrink-Wrap Polymers for Mechanical Induction of Tissue Differentiation by Basma Hashmi, Lauren D. Zarzar, Tadanori Mammoto, Akiko Mammoto, Amanda Jiang, Joanna Aizenberg, and Donald E. Ingber. Advanced Materials Article first published online: 18 FEB 2014 DOI: 10.1002/adma.201304995

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

This paper is behind a paywall.

Studying corrosion from the other side

Corrosion can be beautiful as well as destructive,

Typically, the process of corrosion has been studied from the metal side of the equation - See more at: http://www.anl.gov/articles/core-corrosion#sthash.ZPqFF13I.dpuf. Courtesy of the Argonne National Laboratory

Typically, the process of corrosion has been studied from the metal side of the equation – See more at: http://www.anl.gov/articles/core-corrosion#sthash.ZPqFF13I.dpuf. Courtesy of the Argonne National Laboratory

A Feb. 18, 2014 news item on Nanowerk expands on the theme of corrosion as destruction (Note: Links have been removed),

Anyone who has ever owned a car in a snowy town – or a boat in a salty sea – can tell you just how expensive corrosion can be.

One of the world’s most common and costly chemical reactions, corrosion happens frequently at the boundaries between water and metal surfaces. In the past, the process of corrosion has mostly been studied from the metal side of the equation.

However, in a new study (“Chloride ions induce order-disorder transition at water-oxide interfaces”), scientists at the Center for Nanoscale Materials at the U.S. Department of Energy’s Argonne National Laboratory investigated the problem from the other side, looking at the dynamics of water containing dissolved ions located in the regions near a metal surface.

The Feb. 14, 2014 Argonne National Laboratory news release by Jared Sagoff, which originated the news item, describes how the scientists conducted their research,

A team of researchers led by Argonne materials scientist Subramanian Sankaranarayanan simulated the physical and chemical dynamics of dissolved ions in water at the atomic level as it corrodes metal oxide surfaces. “Water-based solutions behave quite differently near a metal or oxide surface than they do by themselves,” Sankaranarayanan said. “But just how the chemical ions in the water interact with a surface has been an area of intense debate.”

Under low-chlorine conditions, water tends to form two-dimensional ordered layers near solid interfaces because of the influence of its strong hydrogen bonds. However, the researchers found that increasing the proportion of chlorine ions above a certain threshold causes a change in which the solution loses its ordered nature near the surface and begins to act similar to water away from the surface. This transition, in turn, can increase the rate at which materials corrode as well as the freezing temperature of the solution.

This switch between an ordered and a disordered structure near the metal surface happens incredibly quickly, in just fractions of a nanosecond. The speed of the chemical reaction necessitates the use of high-performance computers like Argonne’s Blue/Gene Q supercomputer, Mira.

To further explore these electrochemical oxide interfaces with high-performance computers, Sankaranarayanan and his colleagues from Argonne, Harvard University and the University of Missouri have also been awarded 40 million processor-hours of time on Mira.

“Having the ability to look at these reactions in a more powerful simulation will give us the opportunity to make a more educated guess of the rates of corrosion for different scenarios,” Sankaranarayanan said. Such studies will open up for the first time fundamental studies of corrosion behavior and will allow scientists to tailor materials surfaces to improve the stability and lifetime of materials.

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

Chloride ions induce order-disorder transition at water-oxide interfaces by Sanket Deshmukh, Ganesh Kamath, Shriram Ramanathan, and Subramanian K. R. S. Sankaranarayanan. Phys. Rev. E 88 (6), 062119 (2013) [5 pages]

This article is behind a paywall on both the primary site and the beta site (the American Physical Society is testing a new website for its publications).

Institute of Electrical and Electronics Engineers (IEEE) 2014 international nanotechnology conference in Toronto, Canada

August 18 – 21, 2014 are the dates for the IEEE (Institute for Electrical and Electronics Engineers) 14th International Conference on Nanotechnology.  The deadline for submitting abstracts is March 15, 2014. Here’s a bit more about the conference, from the homepage,

IEEE Nano is one of the largest Nanotechnology conferences in the world, bringing together the brightest engineers and scientists through collaboration and the exchange of ideas.

IEEE Nano 2014 will provide researchers and others in the Nanotechnology field the ability to interact and advance their work through various speakers and workshop sessions.

Possible Topics for Papers

Environmental Health and Safety of Nanotechnology
Micro-to-nano-scale bridging
Modeling and Simulation
•Applications of Biopolymer Nanoparticles for Drug Delivery
•Non-Carbon Based
•Carbon Based
•Circuits and Architecture
Nanofabrication and Nanoassemblies
•Modeling and Theory
•2-D Materials beyond Graphene
•Synthesis and Characterization
•Applications and Enabled Systems
Nanometrology and Nanocharacterization
Nano-optics, Nano-optoelectronics and Nano-photonics:
•Novel fabrication and integration approaches
•Optical Nano-devices
Nanorobotics and Nanomanipulation
Nanoscale Communication and Networks
Nanosensors and Actuators
Nanotechnology Enabled Energy

There is a conference Call For Papers webpage where you can get more information.

Invited speakers include,

John Polanyi
University of Toronto, Canada

John Polanyi, educated at Manchester University, England, was a postdoctoral fellow at Princeton University and at the National Research Council of Canada. He is a faculty member in the Department of Chemistry at the University of Toronto, a member of the Queen’s Privy Council for Canada (P.C.), and a Companion of the Order of Canada (C.C.). His awards include the 1986 Nobel Prize in Chemistry. He has written extensively on science policy, the control of armaments, peacekeeping and human rights.

Charles Lieber
Professor Charles M. Lieber
Mark Hyman Professor of Chemistry
Department of Chemistry and Chemical Biology
Harvard University

Charles M. Lieber is regarded as a leading chemist worldwide and recognized as a pioneer in the nanoscience and nanotechnology fields. He completed his doctoral studies at Stanford University and currently holds a joint appointment in the Department of Chemistry and Chemical Biology at Harvard University, as the Mark Hyman Professor of Chemistry, and the School of Engineering and Applied Sciences. Lieber is widely known for his contributions to the synthesis, understanding and assembly of nanoscale materials, as well as the founding of two nanotechnology companies: Nanosys and Vista Therapeutics.

Lieber’s achievements have been recognized by a large number of awards, including the Feynman Prize for Nanotechnology (2002), World Technology award in Materials (2003 and 2004) and the Wolf Prize in Chemistry (2012). He has published more than 350 papers in peer-reviewed journals and is the primary inventor on over 35 patents.

Arthur Carty
Professor & Executive Director [Waterloo Institute for Nanotechnology]
University of Waterloo, Canada

Arthur Carty has a PhD in inorganic chemistry from the University of Nottingham in the UK. He is currently the Executive Director of the Waterloo Institute for Nanotechnology and research professor in the Department of Chemistry at the University of Waterloo.

Previously, Dr. Carty served in Canada as the National Science Advisor to the Prime Minister and President of the National Research Council (Canada). He was awarded the Order of Canada and holds 14 honorary doctorates.

His research interests are focused on organometallic chemistry and new materials. [Dr. Carty is chair of The Expert Panel on the State of Canada’s Science Culture; an assessment being conducted by the Canadian Council of Academies as per my Feb. 22, 2013 posting and Dr. Carty is giving a Keynote lecture titled: 'Small World, Large Impact: Driving a Materials Revolution Through Nanotechnology' at the 2014 TAPPI (Technical Association for the Pulp, Paper, Packaging and Converting Industries) nanotechnology conference, June 23-26, 2014 in Vancouver, Canada as per my Nov. 14, 2013 posting.]

William Milne
University of Cambridge, UK

Bill Milne FREng,FIET,FIMMM has been Head of Electrical Engineering at Cambridge University since 1999 and Director of the Centre for Advanced Photonics and Electronics (CAPE) since 2005. In 1996 he was appointed to the ‘‘1944 Chair in Electrical Engineering’’. He obtained his BSc from St Andrews University in Scotland in 1970 and then went on to read for a PhD in Electronic Materials at Imperial College London. He was awarded his PhD and DIC in 1973 and, in 2003, a D.Eng (Honoris Causa) from University of Waterloo, Canada. He was elected a Fellow of The Royal Academy of Engineering in 2006. He was awarded the J.J. Thomson medal from the IET in 2008 and the NANOSMAT prize in 2010 for excellence in nanotechnology. His research interests include large area Si and carbon based electronics, graphene, carbon nanotubes and thin film materials. Most recently he has been investigating MEMS, SAW and FBAR devices and SOI based micro heaters for ( bio) sensing applications. He has published/presented ~ 800 papers in these areas, of which ~ 150 were invited. He co-founded Cambridge Nanoinstruments with 3 colleagues from the Department and this was bought out by Aixtron in 2008 and in 2009 co-founded Cambridge CMOS Sensors with Julian Gardner from Warwick Univ. and Florin Udrea from Cambridge Univ.

Shuit-Tong Lee
Institute of Functional Nano & Soft Materials (FUNSOM)
Collaboration Innovation Center of Suzhou Nano Science and Technology
College of Nano Science and Technology (CNST)
Soochow University, China
Email: [email protected]

Prof. Lee is the member (academician) of Chinese Academy of Sciences and the fellow of TWAS (the academy of sciences for the developing world). He is a distinguished scientist in material science and engineering. Prof. Lee is the Founding Director of Functional Nano & Soft Materials Laboratory (FUNSOM) and Director of the College of Chemistry, Chemical Engineering and Materials Science at Soochow University. He is also a Chair Professor of Materials Science and Founding Director of the Center of Super-Diamond and Advanced Films (COSDAF) at City University of Hong Kong and the Founding Director of Nano-Organic Photoelectronic Laboratory at the Technical Institute of Physics and Chemistry, CAS. He was the Senior Research Scientist and Project Manager at the Research Laboratories of Eastman Kodak Company in the US before he joined City University of Hong Kong in 1994. He won the Humboldt Senior Research Award (Germany) in 2001 and a Croucher Senior Research Fellowship from the Croucher Foundation (HK) in 2002 for the studies of “Nucleation and growth of diamond and new carbon based materials” and “Oxide assisted growth and applications of semiconducting nanowires”, respectively. He also won the National Natural Science Award of PRC (second class) in 2003 and 2005 for the above research achievements. Recently, he was awarded the 2008 Prize for Scientific and Technological Progress of Ho Leung Ho Lee Foundation. Prof. Lee’s research work has resulted in more than 650 peer-reviewed publications in prestigious chemistry, physics and materials science journals, 6 book chapters and over 20 US patents, among them 5 papers were published in Science and Nature (London) and some others were selected as cover papers. His papers have more than 10,000 citations by others, which is ranked within world top 25 in the materials science field according to ESI and ISI citation database.

Sergej Fatikow
Full Professor, Dr.-Ing. habil.
Head, Division for Microrobotics & Control Engineering (AMiR)
University of Oldenburg, Germany

Professor Sergej Fatikow studied electrical engineering and computer science at the Ufa Aviation Technical University in Russia, where he received his doctoral degree in 1988 with work on fuzzy control of complex non-linear systems. After that he worked until 1990 as a lecturer at the same university. During his work in Russia he published over 30 papers and successfully applied for over 50 patents in intelligent control and mechatronics. In 1990 he moved to the Institute for Process Control and Robotics at the University of Karlsruhe in Germany, where he worked as a postdoctoral scientific researcher and since 1994 as Head of the research group “Microrobotics and Micromechatronics”. He became an assistant professor in 1996 and qualified for a full faculty position by habilitation at the University of Karlsruhe in 1999. In 2000 he accepted a faculty position at the University of Kassel, Germany. A year later, he was invited to establish a new Division for Microrobotics and Control Engineering (AMiR) at the University of Oldenburg, Germany. Since 2001 he is a full professor in the Department of Computing Science and Head of AMiR. His research interests include micro- and nanorobotics, automated robot-based nanohandling in SEM, AFM-based nanohandling, sensor feedback at nanoscale, and neuro-fuzzy robot control. He is author of three books on microsystem technology, microrobotics and microassembly, robot-based nanohandling, and automation at nanoscale, published by Springer in 1997, Teubner in 2000, and Springer in 2008. Since 1990 he published over 100 book chapters and journal papers and over 200 conference papers. Prof. Fatikow is Founding Chair of the International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO) and Europe- Chair of IEEE-RAS Technical Committee on Micro/Nano Robotics and Automation.

Seiji Samukawa
Distinguished Professor
Innovative Energy Research Center, Institute of Fluid Science, Tohoku University
World Premier International Center Initiative, Advanced Institute for Materials Research, Tohoku University, Sendai, Japan

Dr. Seiji Samukawa received a BSc in 1981 from the Faculty of Technology of Keio University and joined NEC Corporation the same year. At NEC Microelectronics Research Laboratories, he was the lead researcher of a group performing fundamental research on advanced plasma etching processes for technology under 0.1 μm. While there, he received the Ishiguro Award—given by NEC’s R&D Group and Semiconductor Business Group— for his work in applying a damage-free plasma etching process to a mass-production line. After spending several years in the business world, however, he returned to Keio University, obtaining a PhD in engineering in 1992. Since 2000, he has served as professor at the Institute of Fluid Science at Tohoku University and developed ultra-low-damage microfabrication techniques that tap into the essential nature of nanomaterials and developed innovative nanodevices. He is also carrying out pioneering, creative research on bio-template technologies, which are based on a completely new concept of treating the super-molecules of living organisms. His motto when conducting research is to “always aim toward eventual practical realization.”

In recognition of his excellent achievements outlined above, he has been elected as a Distinguished Professor of Tohoku University and has been a Fellow of the Japan Society of Applied Physics since 2008 and a Fellow of the American Vacuum Society since 2009. His significant scientific achievements earned him the Outstanding Paper Award at the International Conference on Micro and Nanotechnology (1997), Best Review Paper Award (2001), Japanese Journal of Applied Physics (JJAP) Editorial Contribution Award (2003), Plasma Electronics Award (2004), Fellow Award (2008), JJAP Paper Award (2008) from the Japan Society of Applied Physics, Distinguished Graduate Award (2005) from Keio University, Ichimura Award (2008) from the New Technology Development Foundation, Commendation for Science and Technology from the Minister of Education, Culture, Sports, Science and Technology (2009), Fellow Award of American Vacuum Society (2009), Plasma Electronics Award from the Japan Society of Applied Physics (2010), Best Paper Award from the Japan Society of Applied Physics (2010), and Plasma Prize from the Plasma Science and Technology Division of American Vacuum Society (2010).

Haixia (Alice) Zhang
Institute of Microelectronics
Peking University, China

Haixia(Alice) Zhang, Professor, Institute of Microelectronics, Peking Universituy. She was served on the general chair of IEEE NEMS 2013 Conference, the organizing chair of Transducers’11. As the founder of the International Contest of Applications in Network of things (iCAN), she organized this world-wide event since 2007. She was elected the director of Integrated Micro/Nano System Engineering Center in 2006, the deputy secretary-general of Chinese Society of Micro-Nano Technology in 2005, the Co-chair of Chinese International NEMS Network (CINN) and serves as the chair of IEEE NTC Beijing Chapter. At 2006, Dr. Zhang won National Invention Award of Science & Technology. Her research fields include MEMS Design and Fabrication Technology, SiC MEMS and Micro Energy Technology.

Alice’s Wonderlab: http://www.ime.pku.edu.cn/alice

I wonder if the organizers will be including an Open Forum as they did at the 13th IEEE nanotechnology conference in China. It sounds a little more dynamic and fun than any of the sessions currently listed for the Toronto conference but these things are sometimes best organized in a relatively spontaneous fashion rather than as one of the more formal conference events (from the 13th conference Open Forum),

This Open Forum will be run like a Rump Session to have a lively discussion of various topics of interest to the IEEE Nanotechnology Community. The key to the success of this Forum is participation from the audience with their own opinions and comments on any Nanotechnology subject or issue they can think of. We expect the session to be lively, interesting, controversial, opinionated and more. Here are some topics or issues to think about:

  1. When are we ever going to have a large scale impact of nanotechnology ? Shouldn’t we be afraid that the stakeholders (Tax payers, Politicians) are going to run out of patience ?
  2. Is there a killer app or apps on the horizon ?
  3. Is there a future for carbon nanotubes in electronics ? It has been 15 years + now….
  4. Is there a future for graphene in electronics ?
  5. Is there a future for graphene in anything ? Or will it just run its course on every application people did previously for carbon nanotubes ?
  6. As engineers, are we doing anything different from the physicists/chemists ? Looks like we are also chasing the same old : trying to publish in Nature, Science, and other similar journals with huge impact factor ? Are we prepared adequately to play in someone else’s game ? Should we even be doing it ?
  7. As engineers, aren’t we supposed to come up with working widgets closer to manufacturing ?
  8. As engineers, are we going to take responsibility for the commercial future of nanotechnology as has been done in all previous success stories ?

This list is by no means exhaustive. Please come up with your own questions/issues and speak up at the session.

Good luck with your abstract.

SLIPS (Slippery Liquid-Infused Porous Surfaces) lead the way to stain-free, self-cleaning clothes

Thanks to the researchers at Harvard University’s Wyss Institute for Biologically Inspired Engineering, I have discovered a new word, omniphobicity. Before getting to this new word, here’s a little more information about the project which spawned the word. According to a Jan. 14, 2014 news item on Nanowerk,

The researchers behind SLIPS (Slippery Liquid-Infused Porous Surfaces) have demonstrated a spate of sleek applications of the super-slick coating since unveiling it in a 2011 issue of Nature – and they just expanded its repertoire even more.

The Jan. ??, 2014 Harvard University Wyss Institute news release, which originated the news item, provides additional information about the SLIPS (Slippery Liquid-Infused Porous Surfaces) technology explaining the engineers have taken their inspiration from the pitcher plant rather the lotus, as is more common,

The team from Harvard’s Wyss Institute and the School of Engineering and Applied Sciences (SEAS) has demonstrated the uncanny ability of SLIPS – inspired by the pitcher plant – to repel nearly any material it contacts: water, ice, oil, saltwater, wax, blood, and more. They have demonstrated its versatility under extreme conditions of pH and temperature, and have successfully used SLIPS to coat everything from refrigeration coils to lenses, windows, and ceramics. What’s more, in 2012 they won an R&D 100 Award for the technology from R&D Magazine. This annual award honors the year’s 100 most significant products, the so-called game-changers of the technology scene.

Here’s what an image illustrating the pitcher plant and SLIPS,

Inspired by the Nepenthes pitcher plant... [Image credit: New Scientist; Bohn & Federie, PNAS 101, 14138-14143, 2004] Courtesy Wyss Institute

Inspired by the Nepenthes pitcher plant… [Image credit: New Scientist; Bohn & Federie, PNAS 101, 14138-14143, 2004] Courtesy Wyss Institute

The team’s latest work features cotton and polyster fabrics (from the news release),

And now, as reported January 10 [2014] in a special issue celebrating the 25th year of the journal Nanotechnology, the team has modified everyday cotton and polyester fabrics to exhibit traditional antifouling SLIPS behavior. The advance could meet the need for a robust, stain-resistant textile for a host of consumer and industrial applications.

“We took one page out of Nature’s book, and are finding that it has the potential to help us develop solutions to a variety of age-old challenges: ice we don’t want on refrigeration coils, bacteria that we don’t want on medical devices, and now stains we don’t want on clothes,” said Joanna Aizenberg, Ph.D., who leads the development of the technology. Aizenberg is a Core Faculty member of the Wyss Institute and the Amy Smith Berylson Professor of Materials Science at SEAS

Most currently available state-of-the-art, stain-resistant fabrics draw their inspiration and design from the lotus leaf. Tiny nanotextures on the surface of lotus leaves resist water, causing droplets of water to bead up on a cushion of air at the edge of the surface. Lotus-inspired textiles therefore use air-filled nanostructures to repel water. These are capable of repelling most aqueous liquids and dirt particles, but they suffer from a series of shortcomings, explained Cicely Shillingford, a Wyss Research Assistant and lead author of the Nanotechnology publication. They require a stable solid-air layer for the beading process to occur and thus fail easily under pressure – as in a heavy rainstorm – and do not withstand physical damage, such as twisting and abrasion, very well. They also stain more easily from organic or complex liquids, such as oil.

On the other hand, SLIPS is inspired by the carnivorous pitcher plant, which locks in a water layer to create a slick coating that causes insects that land on it to literally hydroplane and fall into the plant. The SLIPS coating anchors a slippery lubricated film infused to a nanoporous solid surface, creating a material that performs exceedingly well under pressure or physical damage, and can resist all kinds of liquids, including oil.
To create a fabric with SLIPS-type functionality, the team bought off-the-shelf cotton and polyester fabrics from stores near their lab in Cambridge, Massachusetts, and developed two ways to chemically treat them. One involved coating them with tiny particles of silica (SiM), and the other required a treatment with sol-gel based alumina (SgB). …

What happened after the team put the SLIPS-fabrics through a ringer of tests performed according to industrial standards – from twisting to rubbing and staining attempts?

“The SLIPS-fabric showed an unprecedented ability to repel a wide range of fluids and resist staining, and it handles physical stresses and strains just fine,” said Aizenberg.

While not every SLIPS-fabric was as breathable (yet) as the researchers hoped, it outperformed currently available stain-resistant fabrics on just about every other measure. As such, the most likely immediate applications could be fabrics needed in potentially extreme environments where breathability is not paramount but exposure to challenging contaminating liquids and biological hazards is involved, such as tactical suits for the military, lab coats, medical clothing, specialty garments for construction and manufacturing, and perhaps even tents and sports stadiums.

The scientists have also provided an image of a lab coat that was partially (sleeves) converted to SLIPS and than stained with a variety of foodstuffs,

Former Wyss Postdoctoral Fellow Tak-Sing Wong, Ph.D., who is now an assistant professor at The Pennsylvania State University, wears a labcoat in which the sleeves were converted to SLIPS, after sprayed with wine, tomato juice, eggs, and more. Courtesy Wyss Institute

Former Wyss Postdoctoral Fellow Tak-Sing Wong, Ph.D., who is now an assistant professor at The Pennsylvania State University, wears a labcoat in which the sleeves were converted to SLIPS, after sprayed with wine, tomato juice, eggs, and more. Courtesy Wyss Institute

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

Fabrics coated with lubricated nanostructures display robust omniphobicity by Cicely Shillingford, Noah MacCallum, Tak-Sing Wong, Philseok Kim and Joanna Aizenberg. Nanotechnology 25 01 4019 doi:10.1088/0957-4484/25/1/014019

This paper is behind a paywall. As for an explanation of the word omniphobicity this abstract is helpful,

The development of a stain-resistant and pressure-stable textile is desirable for consumer and industrial applications alike, yet it remains a challenge that current technologies have been unable to fully address. Traditional superhydrophobic surfaces, inspired by the lotus plant, are characterized by two main components: hydrophobic chemical functionalization and surface roughness. While this approach produces water-resistant surfaces, these materials have critical weaknesses that hinder their practical utility, in particular as robust stain-free fabrics. For example, traditional superhydrophobic surfaces fail (i.e., become stained) when exposed to low-surface-tension liquids, under pressure when impacted by a high-velocity stream of water (e.g., rain), and when exposed to physical forces such as abrasion and twisting. We have recently introduced slippery lubricant-infused porous surfaces (SLIPS), a self-healing, pressure-tolerant and omniphobic surface, to address these issues. [emphasis mine] Herein we present the rational design and optimization of nanostructured lubricant-infused fabrics and demonstrate markedly improved performance over traditional superhydrophobic textile treatments: SLIPS-functionalized cotton and polyester fabrics exhibit decreased contact angle hysteresis and sliding angles, omni-repellent properties against various fluids including polar and nonpolar liquids, pressure tolerance and mechanical robustness, all of which are not readily achievable with the state-of-the-art superhydrophobic coatings.

If I understand it rightly the researchers are using the word omniphobic (omni meaning ‘all’ or ‘everything’) to imply that this surface repels liquids in many more situations, e.g. high-velocity stream of water (rain) than the superhydrophobic materials.

Getting neuromorphic with a synaptic transistor

Scientists at Harvard University (Massachusetts, US) have devised a transistor that simulates the synapses found in brains. From a Nov. 2, 2013 news item on ScienceDaily,

It doesn’t take a Watson to realize that even the world’s best supercomputers are staggeringly inefficient and energy-intensive machines.

Our brains have upwards of 86 billion neurons, connected by synapses that not only complete myriad logic circuits; they continuously adapt to stimuli, strengthening some connections while weakening others. We call that process learning, and it enables the kind of rapid, highly efficient computational processes that put Siri and Blue Gene to shame.

Materials scientists at the Harvard School of Engineering and Applied Sciences (SEAS) have now created a new type of transistor that mimics the behavior of a synapse. The novel device simultaneously modulates the flow of information in a circuit and physically adapts to changing signals.

Exploiting unusual properties in modern materials, the synaptic transistor could mark the beginning of a new kind of artificial intelligence: one embedded not in smart algorithms but in the very architecture of a computer. [emphasis mine]

There are two other projects that I know of (and I imagine there are others) focused on intelligence that’s embedded rather than algorithmic. My December 24, 2012 posting focused on a joint (National Institute for Materials Science in Japan and the University of California, Los Angeles) project where researchers developed a nanoionic device with a range of neuromorphic and electrical properties. There’s also the memristor mentioned in my Feb. 26, 2013 posting (and many other times on this blog) which features a ,proposal to create an artificial brain.

Getting back to Harvard’s synaptic transistor (from the Nov. 1, 2013 Harvard University news release which originated the news item),

The human mind, for all its phenomenal computing power, runs on roughly 20 Watts of energy (less than a household light bulb), so it offers a natural model for engineers.

“The transistor we’ve demonstrated is really an analog to the synapse in our brains,” says co-lead author Jian Shi, a postdoctoral fellow at SEAS. “Each time a neuron initiates an action and another neuron reacts, the synapse between them increases the strength of its connection. And the faster the neurons spike each time, the stronger the synaptic connection. Essentially, it memorizes the action between the neurons.”

In principle, a system integrating millions of tiny synaptic transistors and neuron terminals could take parallel computing into a new era of ultra-efficient high performance.

Here’s an image of synaptic transistors that the researchers from Harvard’s School of Engineering and Applied Science (SEAS) have supplied,

Several prototypes of the synaptic transistor are visible on this silicon chip. (Photo by Eliza Grinnell, SEAS Communications.)

Several prototypes of the synaptic transistor are visible on this silicon chip. (Photo by Eliza Grinnell, SEAS Communications.)

The news release provides a description of the synatpic transistor and how it works,

While calcium ions and receptors effect a change in a biological synapse, the artificial version achieves the same plasticity with oxygen ions. When a voltage is applied, these ions slip in and out of the crystal lattice of a very thin (80-nanometer) film of samarium nickelate, which acts as the synapse channel between two platinum “axon” and “dendrite” terminals. The varying concentration of ions in the nickelate raises or lowers its conductance—that is, its ability to carry information on an electrical current—and, just as in a natural synapse, the strength of the connection depends on the time delay in the electrical signal.

Structurally, the device consists of the nickelate semiconductor sandwiched between two platinum electrodes and adjacent to a small pocket of ionic liquid. An external circuit multiplexer converts the time delay into a magnitude of voltage which it applies to the ionic liquid, creating an electric field that either drives ions into the nickelate or removes them. The entire device, just a few hundred microns long, is embedded in a silicon chip.

The synaptic transistor offers several immediate advantages over traditional silicon transistors. For a start, it is not restricted to the binary system of ones and zeros.

“This system changes its conductance in an analog way, continuously, as the composition of the material changes,” explains Shi. “It would be rather challenging to use CMOS, the traditional circuit technology, to imitate a synapse, because real biological synapses have a practically unlimited number of possible states—not just ‘on’ or ‘off.’”

The synaptic transistor offers another advantage: non-volatile memory, which means even when power is interrupted, the device remembers its state.

Additionally, the new transistor is inherently energy efficient. The nickelate belongs to an unusual class of materials, called correlated electron systems, that can undergo an insulator-metal transition. At a certain temperature—or, in this case, when exposed to an external field—the conductance of the material suddenly changes.

“We exploit the extreme sensitivity of this material,” says Ramanathan [principal investigator and associate professor of materials science at Harvard SEAS]. “A very small excitation allows you to get a large signal, so the input energy required to drive this switching is potentially very small. That could translate into a large boost for energy efficiency.”

The nickelate system is also well positioned for seamless integration into existing silicon-based systems.

“In this paper, we demonstrate high-temperature operation, but the beauty of this type of a device is that the ‘learning’ behavior is more or less temperature insensitive, and that’s a big advantage,” says Ramanathan. “We can operate this anywhere from about room temperature up to at least 160 degrees Celsius.”

For now, the limitations relate to the challenges of synthesizing a relatively unexplored material system, and to the size of the device, which affects its speed.

“In our proof-of-concept device, the time constant is really set by our experimental geometry,” says Ramanathan. “In other words, to really make a super-fast device, all you’d have to do is confine the liquid and position the gate electrode closer to it.”

In fact, Ramanathan and his research team are already planning, with microfluidics experts at SEAS, to investigate the possibilities and limits for this “ultimate fluidic transistor.”

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

A correlated nickelate synaptic transistor by Jian Shi, Sieu D. Ha, You Zhou, Frank Schoofs, & Shriram Ramanathan. Nature Communications 4, Article number: 2676 doi:10.1038/ncomms3676 Published 31 October 2013

This article is behind a paywall.

Chameleon materials

Harvard’s School of Engineering and Applied Sciences researchers discovered some unexpected properties when testing a new coating according to an Oct. 22, 2013 news item on Azonano,

Active camouflage has taken a step forward at the Harvard School of Engineering and Applied Sciences (SEAS), with a new coating that intrinsically conceals its own temperature to thermal cameras.

In a laboratory test, a team of applied physicists placed the device on a hot plate and watched it through an infrared camera as the temperature rose. Initially, it behaved as expected, giving off more infrared light as the sample was heated: at 60 degrees Celsius it appeared blue-green to the camera; by 70 degrees it was red and yellow. At 74 degrees it turned a deep red—and then something strange happened. The thermal radiation plummeted. At 80 degrees it looked blue, as if it could be 60 degrees, and at 85 it looked even colder. Moreover, the effect was reversible and repeatable, many times over.

The Oct. 21, 2013 Harvard University news release (also on EurekAlert), which originated the news item, discusses the potential for this discovery and describes the process of discovery in more detail (Note: A link has been removed),

Principal investigator Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at Harvard SEAS, predicts that with only small adjustments the coating could be used as a new type of thermal camouflage or as a kind of encrypted beacon to allow soldiers to covertly communicate their locations in the field.

The secret to the technology lies within a very thin film of vanadium oxide, an unusual material that undergoes dramatic electronic changes when it reaches a particular temperature. At room temperature, for example, pure vanadium oxide is electrically insulating, but at slightly higher temperatures it transitions to a metallic, electrically conductive state. During that transition, the optical properties change, too, which means special temperature-dependent effects—like infrared camouflage—can also be achieved.

The insulator-metal transition has been recognized in vanadium oxide since 1959. However, it is a difficult material to work with: in bulk crystals, the stress of the transition often causes cracks to develop and can shatter the sample. Recent advances in materials synthesis and characterization—especially those by coauthor Shriram Ramanathan, Associate Professor of Materials Science at Harvard SEAS—have allowed the creation of extremely pure samples of thin-film vanadium oxide, enabling a burst of new science and engineering to take off in just the last few years.

“Thanks to these very stable samples that we’re getting from Prof. Ramanathan’s lab, we now know that if we introduce small changes to the material, we can dramatically change the optical phenomena we observe,” explains lead author Mikhail Kats, a graduate student in Capasso’s group at Harvard SEAS. “By introducing impurities or defects in a controlled way via processes known as doping, modifying, or straining the material, it is possible to create a wide range of interesting, important, and predictable behaviors.”

By doping vanadium oxide with tungsten, for example, the transition temperature can be brought down to room temperature, and the range of temperatures over which the strange thermal radiation effect occurs can be widened. Tailoring the material properties like this, with specific outcomes in mind, may enable engineering to advance in new directions.

The researchers say a vehicle coated in vanadium oxide tiles could potentially mimic its environment like a chameleon, appearing invisible to an infrared camera with only very slight adjustments to the tiles’ actual temperature—a far more efficient system than the approaches in use today.

Tuned differently, the material could become a component of a secret beacon, displaying a particular thermal signature on cue to an infrared surveillance camera. Capasso’s team suggests that the material could be engineered to operate at specific wavelengths, enabling simultaneous use by many individually identifiable soldiers.

And, because thermal radiation carries heat, the researchers believe a similar effect could be employed to deliberately speed up or slow down the cooling of structures ranging from houses to satellites.

The Harvard team’s most significant contribution is the discovery that nanoscale structures that appear naturally in the transition region of vanadium oxide can be used to provide a special level of tunability, which can be used to suppress thermal radiation as the temperature rises. The researchers refer to such a spontaneously structured material as a “natural, disordered metamaterial.”

“To artificially create such a useful three-dimensional structure within a material is extremely difficult,” says Capasso. “Here, nature is giving us what we want for free. By taking these natural metamaterials and manipulating them to have all the properties we want, we are opening up a new area of research, a completely new direction of work. We can engineer new devices from the bottom up.”

Here’s an image, from the scientists, illustrating the material’s thermal camouflage (or chameleon) properties,

A new coating intrinsically conceals its own temperature to thermal cameras. (Image courtesy of Mikhail Kats.)

A new coating intrinsically conceals its own temperature to thermal cameras. (Image courtesy of Mikhail Kats.)

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

Vanadium Dioxide as a Natural Disordered Metamaterial: Perfect Thermal Emission and Large Broadband Negative Differential Thermal Emittance by Mikhail A. Kats, Romain Blanchard, Shuyan Zhang, Patrice Genevet, Changhyun Ko, Shriram Ramanathan, and Federico Capasso. Phys. Rev. X » Volume 3 » Issue 4  or Phys. Rev. X 3, 041004 (2013) DOI:10.1103/PhysRevX.3.041004

This paper is published in an open access journal according to the Harvard news release,

About Physical Review X

Launched in August 2011, PRX (http://prx.aps.org) is an open-access, peer-reviewed publication of the American Physical Society (www.aps.org), a non-profit membership organization working to advance and diffuse the knowledge of physics through its outstanding research journals, scientific meetings, and education, outreach, advocacy and international activities. APS represents 50,000 members, including physicists in academia, national laboratories and industry in the United States and throughout the world.

Chart junk: rethinking science data visualization

Which of these visualizations will you remember later? (Images courtesy of Michelle Borkin, Harvard SEAS.)

Which of these visualizations will you remember later? (Images courtesy of Michelle Borkin, Harvard SEAS.)

This chart of data visualization images accompanies an Oct. 16, 2013 news item on ScienceDaily concerning some research into what makes some charts more memorable than others,

It’s easy to spot a “bad” data visualization — one packed with too much text, excessive ornamentation, gaudy colors, and clip art. Design guru Edward Tufte derided such decorations as redundant at best, useless at worst, labeling them “chart junk.” Yet a debate still rages among visualization experts: Can these reviled extra elements serve a purpose?

Taking a scientific approach to design, researchers from Harvard University and Massachusetts Institute of Technology are offering a new take on that debate. The same design elements that attract so much criticism, they report, can also make a visualization more memorable.

Detailed results were presented this week at the IEEE Information Visualization (InfoVis) conference in Atlanta, hosted by the Institute of Electrical and Electronics Engineers.

The Oct. 16, 2013 School of Engineering and Applied Sciences (SEAS) Harvard University news release (also on EurekAlert), which originated the news item, details some of the ways in which the researchers attempted to study data visualizations and memorability (Note: Links from the news release to be found on the SEAS website have been removed),

For lead author Michelle Borkin, a doctoral student at the Harvard School of Engineering and Applied Sciences (SEAS), memorability has a particular importance:

“I spend a lot of my time reading these scientific papers, so I have to wonder, when I walk away from my desk, what am I going to remember? Which of the figures and visualizations in these publications are going to stick with me?”

But it’s more than grad-school anxiety. Working at the interface of computer science and psychology, Borkin specializes in the visual representation of data, looking for the best ways to communicate and interpret complex information. The applications of her work have ranged from astronomy to medical diagnostics and may already help save lives.

Her adviser, Hanspeter Pfister, An Wang Professor of Computer Science at Harvard SEAS, was intrigued by the chart junk debate, which has flared up on design blogs and at visualization conferences year after year.

Together, they turned to Aude Oliva, a principal research scientist at MIT’s Computer Science and Artificial Intelligence Lab, and a cognitive psychologist by training. Oliva’s lab has been studying visual memory for about six years now. Her team has found that in photographs, faces and human-centric scenes are typically easy to remember; landscapes are not.

“All of us are sensitive to the same kinds of images, and we forget the same kind as well,” Oliva says. “We like to believe our memories are unique, that they’re like the soul of a person, but in certain situations it’s as if we have the same algorithm in our heads that is going to be sensitive to a particular type of image. So when you find a result like this in photographs, you want to know: is it generalizable to many types of materials—words, sound, images, graphs?”

“Speaking with [Pfister] and his group, it became very exciting, the idea that we could study what makes a visualization memorable or not,” Oliva recalls. “If it turned out to be the same for everyone, we thought this would be a win-win result.”

For Oliva’s group, it would provide more evidence of cognitive similarities in the brain’s visual processing, from person to person. For Pfister’s group, it could suggest that certain design principles make visualizations inherently more memorable than others.

With Harvard students Azalea A. Vo ’13 and Shashank Sunkavalli SM ’13, as well as MIT graduate students Zoya Bylinskii and Phillip Isola, the team designed a large-scale study—in the form of an online game—to rigorously measure the memorability of a wide variety of visualizations. They collected more than 5,000 charts and graphics from scientific papers, design blogs, newspapers, and government reports and manually categorized them by a wide range of attributes. Serving them up in brief glimpses—just one second each—to participants via Amazon Mechanical Turk, the researchers tested the influence of features like color, density, and content themes on users’ ability to recognize which ones they had seen before.

The results meshed well with Oliva’s previous results, but added several new insights.

“A visualization will be instantly and overwhelmingly more memorable if it incorporates an image of a human-recognizable object—if it includes a photograph, people, cartoons, logos—any component that is not just an abstract data visualization,” says Pfister. “We learned that any time you have a graphic with one of those components, that’s the most dominant thing that affects the memorability.”

Visualizations that were visually dense proved memorable, as did those that used many colors. Other results were more surprising.

“You’d think the types of charts you’d remember best are the ones you learned in school—the bar charts, pie charts, scatter plots, and so on,” Borkin says. “But it was the opposite.”

Unusual types of charts, like tree diagrams, network diagrams, and grid matrices, were actually more memorable.

“If you think about those types of diagrams—for example, tree diagrams that show relationships between species, or diagrams that explain a molecular chemical process—every one of them is going to be a little different, but the branching structures feel very natural to us,” explains Borkin. “That combination of the familiar and the unique seems to influence the memorability.”

The best type of chart to use will always depend on the data, but for designers who are required to work within a certain style—for example, to achieve a recognizable consistency within a magazine—the results may be reassuring.

“A graph can be simple or complex, and they both can be memorable,” explains Oliva. “You can make something familiar either by keeping it simple or by having a little story around it. It’s not really that you should choose to use one color or many, or to include additional ornaments or not. If you need to keep it simple because it’s the style your boss likes or the style of your publication, you can still find a way to make it memorable.”

At this stage, however, the team hesitates to issue any sweeping design guidelines for an obvious reason: memorability isn’t the only thing that matters. Visualizations must also be accurate, easy to comprehend, aesthetically pleasing, and appropriate to the context.

“A memorable visualization is not necessarily a good visualization,” Borkin cautions. “As a community we need to keep asking these types of questions: What makes a visualization engaging? What makes it comprehensible?”

As for the chart junk, she says diplomatically, “I think it’s going to be an ongoing debate.”

I believe Michelle Borkin is the lead author of an unpublished (as yet) paper submitted to the 2013 IEEE Information Visualization (InfoVis) conference, which means I can’t offer a link to or a citation for the paper.