Mildred Dresselhaus: The Queen of Carbon Science

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 Mildred Dresselhaus: The Queen of Carbon Science 


There's an old proverb in science that says," We make progress by standing on the shoulders of the giants". Sometimes a researcher will spend their entire life doing important foundational work which paves the path for others to make discoveries later. One such giant was Mildred Dresselhaus.

Mildred Dresselhaus (November 11, 1930 – February 20, 2017), known as the "Queen of Carbon Science", was an American physicist, materials scientist, and nanotechnologist. Born in Brooklyn, New York, she attended Hunter College where she was mentored by Rosalyn Yalow who went on to become a future Nobel laureate. Dresselhaus further went on to study at Cambridge University and the University of Chicago under the renowned physicist Enrico Fermi. After completing her PhD on semiconductors, she started her pioneering work on carbon at MIT and married her fellow physicist, Gene Dresselhaus. She stayed there for almost 60 years and became the first woman to reach MIT's highest rank professor. She was an institute professor of physics and electrical engineering at the Massachusetts Institute of Technology. Dresselhaus also served as the president of the American Physical Society, the chair of the American Association for Advancement of Science, as well as the director of science in the US Department of Energy under the Bill Clinton Government.

Dresselhaus won numerous awards including the Presidential Medal of Freedom, the National Medal of Science, the Enrico Fermi Award, the Kavli Prize, and the Vannevar Bush Award.

 

                       

Her research focused on the unique properties of nanomaterials, particularly in the area of carbon nanotubes. These cylindrical structures, composed of carbon atoms, opened up new possibilities for their use in various applications, including electronics, energy storage, and medicine. Her work showed that when the dimensions of nanomaterials change, their properties can undergo drastic transformations. This insight has paved the way for the development of heat-resistant plastics, next-generation transistors, and other innovative applications.

In the late 90s, she moved on to a new research area and revolutionized it. Her work was on the so-called Thermoelectric effect, where materials convert residual heat into electricity. According to Enrico Fermi, Electrons in materials can only have a specific amount of energy and if one energy level is occupied, no other electron can occupy it. Also, electrons want to have as low energy as possible so they start to occupy energy levels from the bottom up

           


In the 1st and 2nd dimensions, the distribution of energy levels is different, such that when the electrons fill them it changes their properties. Hence, the electrons here are forced to reconfigure themselves. Dresselhaus showed that this could change how material could convert heat by a factor of 10 and also showed that being in 1D and 2D also changed how material could bounce off heat particles off the material in the form of quasiparticles known as phonons which act like a particle of heat. When particles bump into other particles when they are hot, that bumping can transfer heat energy. This process acts similar to how materials emit and absorb light; by producing and consuming photons. So, it makes sense that materials do produce and consume phonons of heat energy too. What Dresselhaus worked out was that the interaction of phonons and electrons was completely different in 1D and 2D materials than in 3D. This important discovery allows the production of more efficient thermoelectric materials

In addition to her contributions to carbon science and nanotechnology, Dresselhaus was a strong advocate for women in science. Throughout her career, she worked tirelessly to encourage more girls to pursue careers in STEM fields. She believed in the importance of diversity and inclusivity in the scientific community and actively promoted opportunities for women to excel in their chosen fields. She also served as a mentor to countless students and young scientists, helping them to overcome barriers and achieve their goals. Her legacy as the "Queen of Carbon Science" will continue to inspire and empower scientists for years.


Credits:

Parag Thawali

Meta Monday, COEP Blogs.

References:

https://www.kavliprize.org/bio/mildred-dresselhaus

https://youtu.be/HAhKh7FXomY?si=uIGuASwpRr3uNgi_

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