Erik Visits an American Grave, Part 1,438

This is the grave of Mildred Dresselhaus.

Born in 1930 in Brooklyn, Mildred Spiewak grew up in a immigrant Jewish family. Both her parents had immigrated from Poland. Good call. The family was poor and Spiewak had to start piecework stitching as a child and worked at a zipper factory in the summer. Given how much of this work had migrated to the South for lower wage by this time, the family must have been very poor indeed. She was really into museums though and went as often as possible to the great Manhattan museums. She was also a very good student. The family lived in The Bronx by this time and she went to the public schools there. An older brother had gotten into Hunter College High School and she followed him there. She was a good tutor and made some extra money that way. Maybe there was a way out for her.

Spiewak then went to Hunter College, where she graduated with a degree in liberal arts in 1951. While she was there, she became increasingly interested in science and received encouragement to explore it in graduate study. That started when she earned a Fulbright and studied at Cambridge. She then went to Radcliffe, where she got an MA, and then Chicago for a PhD in physics. There, she studied under Enrico Fermi, so yeah, I’d say that is a good background. Now, it was not easy for a woman to get hired in the sciences during these years, but she managed to do it after a couple of years on a postdoc at Cornell. MIT hired her and she stayed there the rest of her career. She married once early, divorced, and then married another physicist named Gene Dresselhaus in 1958. He outlived her and died in 2021 in California, but either did not get buried next to her or there was no sign of it. Maybe he is there now, I don’t know, I took this one awhile ago.

Anyway, Mildred Dresselhaus became one of the nation’s leading physicists, which meant she was one of the world’s leading physicists too. Of course, the entire field of physics is almost completely lost on me. I can read a lot of scientific papers and have had to for various bits of work, but reading physics papers without a real background in it is…..pretty confounding! What I can say is that she was interested in what are sometimes described as “exotic compounds.” She was noted for her work on graphite, which doesn’t sound very exotic to me, but what do I know. Moreover, this work was critical for the development of smartphones, which I do know about. Thanks Mildred! She was also involved in research around low-dimensional thermodynamics, which must be interesting, but there’s not even a good description of it when you google the term, just a bunch of links to research that I don’t understand. She did some government service as well, including directing the Office of Science for the Department of Energy in 2000 and 2001.

Importantly, Dresselhaus saw herself as a pioneer for women in the sciences and worked hard to open up other opportunities for women in science. That she was at MIT meant that a lot of her work there in the service sector of her job went into fighting for more space for women in science and engineering, including both at the student and faculty level. Late in life, in 2017, she was even in a General Electric ad promoting women in science. The American Physics Society created the Millie Dresselhaus Award to honor leading women in the field.

To describe some of her work, I am just going to quote from her MIT page. Those of you can understand this, have at it:

Recent research activities in the Dresselhaus group that have attracted wide attention are in the areas of carbon nanotubes, bismuth nanowires and low dimensional thermoelectricty.

Regarding carbon nanotubes, which were previously predicted to be either semiconducting or metallic depending on their geometries, we have been developing the method of Raman spectroscopy as a sensitive tool for the characterization of single wall carbon nanotubes, one atomic layer in wall thickness. This work started in earnest with the initial observation (with Rao et al. at the University of Kentucky in 1997) of the Raman spectra from bundles of single wall carbon nanotubes and showing a strong enhancement of the spectra through a diameter selective resonance Raman effect. Next we showed characteristic differences between the Raman profile of the G-band depending on whether the nanotubes were metallic or semiconducting. This work eventually led to the observation of Raman spectra from one single nanotube, with intensities under good resonance conditions comparable to that from the silicon substrate, even though the ratio of carbon to silicon atoms in the light beam was approximately only one carbon atom to one hundred million silicon atoms. All Raman features normally observed in single wall nanotube (SWNT) bundles are also observed in spectra at the single nanotube level, including the radial breathing mode, the G-band, the D-band and the G’-band. However, at the single nanotube level, the characteristics of each feature can be studied in detail, including its dependence on diameter, chirality, laser excitation energy and closeness to resonance with electronic transitions. Of particular importance is the uniqueness of the electronic transition energies for each nanotube, which are described in terms of two integers (n, m) which uniquely specify the geometrical structure of the nanotube, including its diameter and chirality. The high sensitivity of the Raman spectra to diameter and chirality, particularly for the characteristics of the radial breathing mode, which are also uniquely related to the same (n, m) indices, thereby providing a structural determination of (n, m) at the single nanotube level. The (n, m) assignments made to individual carbon nanotubes are corroborated by measuring the characteristics of other features in the Raman spectra that are sensitive to nanotube diameter and chirality. Raman spectroscopy potentially provides a convenient way to characterize nanotubes for their (n, m) indices, in a manner that is compatible with the measurement of other nanotube properties, such as transport, mechanical and electronic properties at the single nanotube level, and the dependence of these properties on nanotube diameter and chirality.

We have devised a way to prepare arrays of aligned bismuth nanowires down to 7 nm diameter (embedded in an anodic alumina template), 50-100 microns in length, with a wire density of ~ 1011/cm2, with their wire axes along a common crystalline orientation, and preserving the crystal structure of bulk bismuth. We previously predicted a semimetal-semiconductor transition in bismuth nanowires as a function of nanowire diameter due to quantum confinement effects, and we have now succeeded in observing this effect through transport measurements. We are now studying the transport and optical properties of the nanowire arrays with particular relevance to enhancing their thermoelectric properties. For scientific studies we are developing techniques to make measurements of the resistance of single quantum wires as a function of nanowire diameter using a 4-probe method. The doping of bismuth with antimony, which is isoelectronic to bismuth, is of special interest for achieving an enhancement in thermoelectric performance, especially for p-type legs in thermoelectric devices. For this reason we are now studying the structure, electronic and transport properties of bismuth-antimony nanowires as a function of nanowire diameter and antimony concentration.

Ur….ok.

More up my alley is noting the many awards Dresselhaus received. She never did win the Nobel, but she won the National Medal of Science in 1990, the Vannevar Bush Award in 2009, the Enrico Fermi Award in 2012, and the Presidential Medal of Freedom in 2014, which is pretty cool. I’m trying to imagine Trump giving an award to someone like this. No, let’s just stop that right now and be thankful for one of the best parts about Obama, which was taking science seriously.

Dresselhaus died in 2017. She was 86 years old. Her MIT obituary called her “The Queen of Carbon.” I am very glad that is on her tombstone.

Mildred Dresselhaus is buried in Mount Auburn Cemetery, Cambridge, Massachusetts.

If you would like this series to visit other leading female scientists, you can donate to cover the required expenses here. Katherine Johnson is in Hampton, Virginia and Grace Hopper is in Arlington. Previous posts in this series are archived here and here.