Tag Archives: Mildred Dresselhaus

R.I.P. Mildred Dresselhaus, Queen of Carbon

I’ve been hearing about Mildred Dresselhaus, professor emerita (retired professor) at the Massachusetts Institute of Technology (MIT), just about as long as I’ve been researching and writing about nanotechnology (about 10 years including the work for my master’s project with the almost eight years on this blog).

She died on Monday, Feb. 20, 2017 at the age of 86 having broken through barriers for those of her gender, barriers for her subject area, and barriers for her age.

Mark Anderson in his Feb. 22, 2017 obituary for the IEEE (Institute of Electrical and Electronics Engineers) Spectrum website provides a brief overview of her extraordinary life and accomplishments,

Called the “Queen of Carbon Science,” Dresselhaus pioneered the study of carbon nanostructures at a time when studying physical and material properties of commonplace atoms like carbon was out of favor. Her visionary perspectives on the sixth atom in the periodic table—including exploring individual layers of carbon atoms (precursors to graphene), developing carbon fibers stronger than steel, and revealing new carbon structures that were ultimately developed into buckyballs and nanotubes—invigorated the field.

“Millie Dresselhaus began life as the child of poor Polish immigrants in the Bronx; by the end, she was Institute Professor Emerita, the highest distinction awarded by the MIT faculty. A physicist, materials scientist, and electrical engineer, she was known as the ‘Queen of Carbon’ because her work paved the way for much of today’s carbon-based nanotechnology,” MIT president Rafael Reif said in a prepared statement.

Friends and colleagues describe Dresselhaus as a gifted instructor as well as a tireless and inspired researcher. And her boundless generosity toward colleagues, students, and girls and women pursuing careers in science is legendary.

In 1963, Dresselhaus began her own career studying carbon by publishing a paper on graphite in the IBM Journal for Research and Development, a foundational work in the history of nanotechnology. To this day, her studies of the electronic structure of this material serve as a reference point for explorations of the electronic structure of fullerenes and carbon nanotubes. Coauthor, with her husband Gene Dresselhaus, of a leading book on carbon fibers, she began studying the laser vaporation of carbon and the “carbon clusters” that resulted. Researchers who followed her lead discovered a 60-carbon structure that was soon identified as the icosahedral “soccer ball” molecular configuration known as buckminsterfullerene, or buckyball. In 1991, Dresselhaus further suggested that fullerene could be elongated as a tube, and she outlined these imagined objects’ symmetries. Not long after, researchers announced the discovery of carbon nanotubes.

When she began her nearly half-century career at MIT, as a visiting professor, women consisted of just 4 percent of the undergraduate student population.  So Dresselhaus began working toward the improvement of living conditions for women students at the university. Through her leadership, MIT adopted an equal and joint admission process for women and men. (Previously, MIT had propounded the self-fulfilling prophecy of harboring more stringent requirements for women based on less dormitory space and perceived poorer performance.) And so promoting women in STEM—before it was ever called STEM—became one of her passions. Serving as president of the American Physical Society, she spearheaded and launched initiatives like the Committee on the Status of Women in Physics and the society’s more informal committees of visiting women physicists on campuses around the United States, which have increased the female faculty and student populations on the campuses they visit.

If you have the time, please read Anderson’s piece in its entirety.

One fact that has impressed me greatly is that Dresselhaus kept working into her eighties. I featured a paper she published in an April 27, 2012 posting at the age of 82 and she was described in the MIT write up at the time as a professor, not a professor emerita. I later featured Dresselhaus in a May 31, 2012 posting when she was awarded the Kavli Prize for Nanoscience.

It seems she worked almost to the end. Recently, GE (General Electric) posted a video “What If Scientists Were Celebrities?” starring Mildred Dresselhaus,

H/t Mark Anderson’s obituary Feb. 22, 2017 piece. The video was posted on Feb. 8, 2017.

Goodbye to the Queen of Carbon!

Congratulations to Mildred Dresselhaus, winner of the 2012 Kavli Prize in Nanoscience

A pioneer in the field, Mildred Dresselhaus has been recognized for her work in nanoscience by the Kavli Foundation. From the May 31, 2012 news item on Nanowerk,

Mildred S. Dresselhaus is recognized with the Kavli Prize for Nanoscience for her seminal contributions to the science of carbon-based nanostructures and for her elucidation of the electron-phonon interaction on the nanoscale.

Dresselhaus has laid the foundation for our understanding of the influence of reduced dimensionality on the fundamental thermal and electrical properties of materials. Her early work on graphite intercalation compounds and carbon fibers presaged the discoveries of C60, the fullerenes, nanotubes, and graphene. She investigated the effects of phonon confinement and electron-phonon interactions in nanostructures, and provided the key insights that underlie today’s research into nanostructured thermoelectrics. She showed that in nanostructures it is possible to decouple thermal and electrical transport, with significant implications for energy use. Thanks to Dresselhaus’s work, we have an improved understanding of how energy flows and dissipates on the nanoscale.

The 2012 Kavli Nanoscience Citation webpage contextualizes her achievements,

The story of carbon is interwoven with the story of nanoscience. The 1996 Chemistry Nobel Prize for the discovery of fullerenes, the 2008 Kavli Nanoscience Prize for the discovery of nanotubes, and the 2010 Physics Nobel Prize for graphene all recognize the remarkable phenomena that occur in highly controlled carbon-based nanostructures. As early as the 1960’s, Dresselhaus led one of the very first groups that explored the carbon materials that form the basis for 2D graphene and 1D carbon nanotubes. These early experiments helped to map out the electronic band structure of these materials, critical to further understanding the unique properties they might possess. Dresselhaus studied intercalated two-dimensional graphene sheets and provided important insights into the properties of not only 2D graphene, but also of the rich interactions between graphene and the surrounding materials. Her early work on carbon fibers, beginning in the 1980’s, provided Dresselhaus with the understanding and perspective to postulate the existence and unusual attributes of one-dimensional ‘single wall carbon nanotubes (SWNTs)’, years in advance of their actual discovery. A key prediction included the possibility that SWNTs could behave like either metals or semiconductors, depending on their chirality. Dresselhaus and coworkers pointed out that nanotubes can be viewed as arising from the folding of a single sheet of carbon, like a piece of paper that is wrapped at different spiral angles. They showed that this very simple rearrangement of their structure completely controlled their properties. This prediction was subsequently shown to be true. Through her studies of the fundamental physics of carbon-based solids, Dresselhaus laid the foundation for knowledge that has been integral to today’s nanoscience of carbon.

Dresselhaus studied the transport and optical properties of nanostructured matter with an exquisite selection of experimental techniques providing unprecedented microscopic understanding. Regarding carbon nanostructures, she pioneered Raman spectroscopy as a sensitive tool for the characterization of materials one atomic layer in wall thickness, namely carbon nanotubes and graphene. Diameter selective resonance enhancement led to the observation of Raman spectra from one single nanotube. The high sensitivity of Raman spectroscopy to diameter and chirality made the technique the prime method for the characterization of carbon nanotubes. The success story has been seamlessly adapted to the characterization of graphene and is in use in hundreds of laboratories worldwide as a fundamental diagnostic tool for carbon-based nanostructures.

Materials are held together by electrons shared between atoms. When the energy of an electron in a solid is altered, the local bonding of the solid is perturbed, resulting in a change in the position of the atoms that make up the solid. In nanoscale materials, the spatial extent of electrons and phonons can be modulated, leading to dramatically different behaviors compared with extended solids. Dresselhaus has investigated this very fundamental electron–phonon interaction in nanostructures using the powerful techniques of Raman and Resonance Raman spectroscopy.

This science also laid a foundation for practical work today aimed at controlling how energy flows. Thermoelectric materials have the ability to convert heat energy to an electrical signal or, alternatively, to utilize electrical energy to actively cool a material. Nature provides materials in which the electrical and thermal conductivity are strongly linked, resulting in a seeming limit to the achievable efficiency of a thermoelectric. Dresselhaus demonstrated that in a one-dimensional structure, it is possible to separately adjust electrical and thermal conductivity, and that this should allow the creation of new generations of thermoelectric refrigerators and new ways of scavenging waste heat for useful purposes.

Dresselhaus recently co-published a paper about developing a new material, a bismuth-antimony film (mentioned in my April 27, 2012 posting). The Wikipedia essay on Mildred Dresselhaus notes that she was born November 11, 1930 and is currently a professor at MIT (Massachusetts Institute of Technology). Note the absence of the word, emerita*.

May 2012 has been an interesting month, I’ve had the opportunity to feature both a octogenerian* and a teenager (Janelle Tam [mentioned in my May 11, 2012 posting]) who prove you can contribute to your chosen field at almost any age.

*’Emeritus’ corrected to ’emerita’ and ‘nonogenerian’ corrected to ‘octogenerian’ on Feb. 22, 2017.

Two-dimensional Dirac cones, bismuth-antimony films, and graphene

Two researchers at MIT (Massachusetts Institute of Technology) have developed a new material, a bismuth-antimony film. From the April 24, 2012 news item by David Chandler for MIT News,

Now, researchers at MIT have found another compound that shares many of graphene’s unusual characteristics — and in some cases has interesting complementary properties to this much-heralded material.

The material, a thin film of bismuth-antimony, can have a variety of different controllable characteristics, the researchers found, depending on the ambient temperature and pressure, the material’s thickness and the orientation of its growth. The research, carried out by materials science and engineering PhD candidate Shuang Tang and Institute Professor Mildred Dresselhaus …

Like graphene, the new material has electronic properties that are known as two-dimensional Dirac cones, a term that refers to the cone-shaped graph plotting energy versus momentum for electrons moving through the material. These unusual properties — which allow electrons to move in a different way than is possible in most materials — may give the bismuth-antimony films properties that are highly desirable for applications in manufacturing next-generation electronic chips or thermoelectric generators and coolers.

In such materials, Tang says, electrons “can travel like a beam of light,” potentially making possible new chips with much faster computational abilities. The electron flow might in some cases be hundreds of times faster than in conventional silicon chips, he says.

Similarly, in a thermoelectric application — where a temperature difference between two sides of a device creates a flow of electrical current — the much faster movement of electrons, coupled with strong thermal insulating properties, could enable much more efficient power production. This might prove useful in powering satellites by exploiting the temperature difference between their sunlit and shady sides, Tang says.

Such applications remain speculative at this point, Dresselhaus says, because further research is needed to analyze additional properties and eventually to test samples of the material. This initial analysis was based mostly on theoretical modeling of the bismuth-antimony film’s properties.

PhD candidate Shuang Tang, left, and Institute Professor Mildred Dresselhaus Photo: Dominick Reuter

While possible applications are purely speculation, the new material appears to have some interesting properties, from the April 24, 2012 news item on Nanowerk,

While it turns out that the thin films of bismuth-antimony can have some properties similar to those of graphene, changing the conditions also allows a variety of other properties to be realized. That opens up the possibility of designing electronic devices made of the same material with varying properties, deposited one layer atop another, rather than layers of different materials.

The material’s unusual properties can vary from one direction to another: Electrons moving in one direction might follow the laws of classical mechanics, for example, while those moving in a perpendicular direction obey relativistic physics. This could enable devices to test relativistic physics in a cheaper and simpler way than existing systems, Tang says, although this remains to be shown through experiments.

“Nobody’s made any devices yet” from the new material, Dresselhaus cautions, but adds that the principles are clear and the necessary analysis should take less than a year to carry out.

Here’s what another researcher (not affiliated with this work) had to say about the new material, from the April 24, 2012 MIT article,

Joseph Heremans, a professor of physics at Ohio State University who was not involved in this research, says that while some unusual properties of bismuth have been known for a long time, “what is surprising is the richness of the system calculated by Tang and Dresselhaus. The beauty of this prediction is further enhanced by the fact that system is experimentally quite accessible.”

Heremans adds that in further research on the properties of the bismuth-antimony material, “there will be difficulties, and a few are already known,” but he says the properties are sufficiently interesting and promising that “this paper should stimulate a large experimental effort.”

So, in about one year, we should know more.

Broader Impacts Criterion and informal science education in the US

Broader Impacts Criterion (BIC), a requirement for US National Science Foundation (NSF) grants covers the areas of science education, science outreach, and the promotion of benefits to society. As you might expect there is support and criticism from scientists and the scientific community about having to include BIC in grant proposals, from the American Physical Society News, June 2007 (volume 16, no. 6),

Bob Eisenstein, Chair of APS’s Panel on Public Affairs, was at NSF when the criterion was first put in place in the mid-1990s. He said that the criterion is meant to serve two purposes: first, it forces scientists to think more carefully about the ways in which their work impacts society, and second, it helps provide the public with more information about what scientists are doing.

Fred Cooper, a current NSF program director for theoretical physics, said his personal opinion is that this is a good thing for NSF to do. “I’m very happy to encourage people to think about these things,” he said. He says it is in scientists’ self-interest to do so.

However, some scientists object to research funding being coupled to education or outreach efforts. Mildred Dresselhaus of MIT says she has heard from many scientists who are unhappy with the broader impacts requirements, and who feel they should be funded based on the quality of their research, not for outreach. …

I gather the criticism was serious enough to warrant a review, excerpted from the July 25, 2011 NISE (Nanoscale Informal Science Education) Net blog posting by Carol Lynn Alpert (BIC requirements have an indirect impact on science museums which benefit from subawards and partnerships with researchers and research institutions seeking to fulfill their BIC obligations),

After reviewing comments from 5,100 stakeholders, the NSB [the National Science Board is the NSF’s governing body] has decided to retain both criteria, but to revise them in order to clarify their intent and “connection to NSF’s core principles” (NSF-11-42, available at http://www.nsf.gov/nsb/publications/2011/06_mrtf.jsp).

As stated by the NSB, these core principles and national goals are led by concerns for global economic and workforce competitiveness, and for the first time allow that “broader impacts” may be achieved “through the research itself.”  This phrase has some worrying that a “BIC loophole” has been created, for it allows that the research itself may be “enough” to enhance U.S economic and workforce competitiveness, without the research team needing to specifically incorporate synergistic activities addressing concomitant K-12 education, diversity, or public engagement goals.

On July 13, AAAS [American Association for the Advancement of Science] submitted a letter to the Chairman of the NSB strongly objecting to what I am here referring to as the “BIC loophole.” AAAS said, “While increasing knowledge serves a public good, it is not always clear how publicly funded research can produce broader impacts unless it is applied and/or widely communicated beyond the scholarly community. The current language appears to offer researchers an excuse not to engage in a more thoughtful consideration of the criterion.”

Here’s a link to the full letter from the AAAS.

I find it fascinating that there’s a discussion about this in the US as the concept of scientists engaging in public outreach does not seem to exist in the same way in Canada. I was able to find Canadian science funding agencies that require some public outreach.  NSERC (Natural Sciences and Engineering Research Council) has a general NSERC policy for public communication,

The Institution [receiving the grant] agrees to:

  1. identify, encourage and assist researchers to communicate with media and participate in announcement events to promote Agency-funded research;
  2. inform, at least five working days before the proposed announcement, if feasible, the Agency’s or Agencies’ public affairs or communications division – normally through the Institution’s own public affairs, communications, or research communications department – of announcements of Agency awards, programs and significant research results that the Institution proposes to make;
  3. include appropriate acknowledgement of the appropriate Agency or Agencies in all relevant public communications issued by the Institution;
  4. respect the relevant Agency or Agencies’ obligation under the Communications Policy of the Government of Canada;
  5. respect the relevant Agency or Agencies’ prerogative to make the first public announcement of its awards, grants and programs, when the relevant Minister declines to do so. It is the purview of a Minister or the Minister’s designate to make public announcements of all federal expenditures; and
  6. share with the Agency or Agencies any promotional material for the general public that is based on Agency-funded research.

So, this NSERC policy is aimed more at the universities and other institutions not the individual researcher.  Also, it seems to be more a guideline or general rule which provides a bit of a contrast  with the Canada Foundation for Innovation (CFI) which lists public communication as a requirement for funding. From the CFI Policy and Program Guide, December 2010,

As part of filing their annual institutional reports (see secion 7.3.2), institutions must provide the CFI with information on the communication activities undertaken in the previous year, along with activities planned for the coming year that are designed to showcase the impacts and outcomes of CFI investments. Institutions are asked to provide information on media activity, publications (print and online) and special events. This information assists the CFI in identifying national trends in research communications, as well as opportunities for collaboration on communications initiatives with institutions. (p. 81)

Women in nanoscience and other sciences too

Last week, three women were honoured for their work in nanoscience with  L’Oréal Singapore for Women in Science Fellowships (from the news item on Nanowerk),

In its second year, the Fellowships is organised with the support of the Singapore National Commission for UNESCO and in partnership with the Agency for Science, Technology and Research (A*STAR). The Fellowships aim to recognise the significant contribution of talented women to scientific progress, encourage young women to pursue science as a career and promote their effective participation in the scientific development of Singapore.

The three outstanding women were awarded fellowships worth S$20,000 to support them in their doctorate or post-doctorate research. This year’s National Fellows are:

– Dr. Low Hong Yee, 2010 L’Oréal Singapore For Women in Science National Fellow and Senior Scientist at A*STAR’s Institute of Materials Research and Engineering. Her work in nanoimprint technology, an emerging technique in nanotechnology, focuses on eco solutions and brings to reality the ability to mimic and apply on synthetic surfaces the structure found in naturally occurring exteriors or skin such as the iridescent colours of a butterfly’s wings or the water-proofing of lotus leaves. This new development offers an eco-friendly, non-chemical method to improve the properties and functionalities of common plastic film.

– Dr. Madhavi Srinivasan, 2010 L’Oréal Singapore For Women in Science National Fellow and Assistant Professor at the Nanyang Technological University. Dr Srinivasan seeks to harness the power of nanoscale materials for the answer to the future of energy storage. Such technologies are vital for the future of a clean energy landscape. Its applications include powering electric vehicles, thus reducing overall CO2 emission, and reducing global warming or enhancing renewable energy sources (solar/wind), thus reducing pollution and tapping on alternative energy supplies.

– Dr. Yang Huiying, 2010 L’Oréal Singapore For Women in Science National Fellow and Assistant Professor at Singapore University of Technology and Design. Dr Yang’s fascination with the beauty of the nano-world prompted her research into the fabrication of metal oxide nanostructures, investigation of their optical properties, and the development of nanophotonics devices. These light emitting devices will potentially be an answer to the need for energy-saving and lower cost display screens, LED bulbs, TV and DVD players etc.

This announcement reminded me of a question I occasionally ask myself, why aren’t there more women mentioned prominently in the nanotechnology/nanoscience narratives? There are a few (the ones I’ve heard of are from the US: Christine Peterson/Foresight Institute; Mildred Dresselhaus, advisor to former US Pres. Bill Clinton; Kristen Kulinowski/Rice University and the Good Nano Guide, please let me know of any others that should be added to this list) just not as many as I would have expected.

On a somewhat related note, there was this blog post by one of the co-authors of the article, The Internet as a resource and support network for diverse geoscientists, which focused largely on women,

In the September issue of GSA Today, you can find our article on The Internet as a resource and support network for diverse geoscientists. We wrote the article with with the idea of reaching beyond the audience that already reads blogs (or attends education/diversity sessions at GSA), with the view that we might be able to open some eyes as to why time spent on-line reading and writing blogs and participating in Twitter might be a valuable thing for geoscientists to be doing. And, of course, we had some data to support our assertions.

As a white woman geoscientist in academia, I have definitely personally and professionally benefited from my blog reading and writing time. (I even have a publication to show for it!) But I would to love to hear more from minority and outside-of-academia geoscientists about what blogs, Twitter, and other internet-based forms of support could be doing to better support you. As you can see from the paragraph above, what we ended up advocating was that institutional support for blogging and blog-reading would help increase participation. We thought that, with increased participation, more minority and outside-of-academia geosciences voices would emerge, helping others find support, community, role models, and mentoring in voices similar to their own. Meanwhile those of us closer to the white/academic end of the spectrum could learn from all that a diverse geoscientist community has to offer.

The 2-page article is open access and can be found here.

Meanwhile, women in technology should be taking this tack according to an article by Allyson Kapin on the Fast Company website,

We have a rampant problem in the tech world. It’s called the blame game. Here’s how it works. You ask the question, “Why aren’t there enough women in tech or launching startups?” From some you get answers like, “Because it’s an exclusive white boys club.” But others say, “Not true! It’s because women don’t promote their expertise enough and they are more risk averse.” How can we truly address the lack of women in tech and startups and develop realistic solutions if we continue to play this silly blame game?

Yesterday, Michael Arrington of TechCrunch wrote a blog post saying, “It doesn’t matter how old you are, what sex you are, what politics you support or what color you are. If your idea rocks and you can execute, you can change the world and/or get really, stinking rich.”

That’s a nice idea and if it were true then the amount of wealthy entrepreneurs would better match our population’s racial and gender demographics. The fact remains that in 2009 angel investors dished out $17.6 billion to fund startups. Wonder how many funded startups were women-run? 9.4%, according to the 2009 angel investor report from Center for Venture Research at University of New Hampshire. And only 6% of investor money funded startups run by people of color.

Yet Arrington says it’s because women just don’t want it enough and that he is sick and tired of being blamed for it. He also says TechCrunch has “beg[ged] women to come and speak” and participate in their events and reached out to communities but many women still decline.

Unfortunately, the article is expositing two different ideas (thank you Allyson Kapin for refuting Arrington’s thesis) and not relating them to each other. First, there is a ‘blame game’ which isn’t getting anyone anywhere and there are issues with getting women to speak on technology panels.There are some good suggestions in the article for how to deal with the 2nd problem while the first problem is left to rest.

Kapin is right, the blame game doesn’t work in anyone’s favour but then we have to develop some alternatives. I have something here from Science Cheerleader which offers a stereotype-breaking approach to dealing with some of the issues that women in science confront. Meet Christine,

Meet Crhstine (image found on sciencecheerleader.com

Meet Erica,

Meet Erica (image found on sciencecheerleader.com)

One of these women is a software engineer and the other is a biomedical engineer.  Do visit Science Cheerleader to figure out which woman does what.

Changing the way women are perceived is a slow and arduous process and requires a great number of strategies along with the recognition that the strategies have to be adjusted as the nature of the prejudice/discrimination also changes in response to the strategies designed to counter it in the first place.  For example, efforts like the L’Oréal fellowships for women have been described as reverse-discrimination since men don’t have access to the awards by reason of their gender while standard fellowship programmes are open to all. It’s true the programmes are open to all but we need to use a variety of ways (finding speakers for panels, special financial awards programmes, stereotype-breaking articles, refuting an uninformed statement, etc.) to encourage greater participation by women and the members of other groups that have traditionally not been included. After all, there’s a reason why most of the prominent Nobel science prize winners  are white males and it’s not because they are naturally better at science.