Introduction to a Nanoscience Pioneer

Mildred Dresselhaus significantly influenced modern nanoscience, particularly in carbon science. Her work focused on understanding and measuring materials at the nanoscale, laying foundational insights rather than single moments of discovery.

Early Career and Focus on Semimetals

In the 1960s, while semiconductors like silicon were popular, Dresselhaus explored the electronic structures of semimetals, graphite, and group V semimetals at the Lincoln Laboratory.

She noted that working in a less competitive research area offered advantages, especially while balancing childcare and research.

Professor Maia Weinstock noted that Dresselhaus embraced the challenge of less-explored fields, seeing opportunities for leadership and less pressure compared to competitive research teams.

The "Carbon Queen" Era at MIT

Dresselhaus joined MIT, where her primary work in the nano-world began, earning her the unofficial title "Carbon Queen." Professor Weinstock clarified that while Dresselhaus worked with various materials, she specialized in carbon for much of her career, and her insights were highly influential.

Initially, carbon was considered a mundane element by many scientists. Her husband, physicist Gene Dresselhaus, suggested she explore carbon, as he believed it held interesting properties. This led her to a field considered less appealing and more challenging to study than silicon.

Groundbreaking Research on Graphite and Graphene

Beginning in the 1960s, Dresselhaus studied graphite, which is composed of graphene layers.

Her early studies on graphite were advanced for their time, some being effectively revisited later when isolating single-layer graphene became feasible.

Her observations contributed to the discovery of fullerenes (buckyballs) and subsequently carbon nanotubes. Professor Weinstock explained that Dresselhaus played a major role in deciphering specific properties within these carbon systems, which share much of the same underlying physics.

As a permanent MIT faculty member in Electrical Engineering, Dresselhaus investigated intercalation compounds. By 1974, her research shifted to vibrational spectra of donor and acceptor compounds, where graphene layers in intercalation compounds could be doped.

She synthesized intercalated superlattices using the staging effect, inserting single-atom-thick guest species between host material layers. Further research revealed that monolayer graphene behaved distinctly from other layers, leading to numerous research papers, PhD theses, and a highly cited review article on graphite intercalation compounds in 1981.

Contributions to Carbon Nanotubes

Dresselhaus significantly contributed to carbon nanotube science by identifying that nanotubes with different atomic configurations possess varying properties. As Professor Weinstock detailed, atomic-level differences in configuration determine if nanotubes function better as heat conductors, physical strengthening agents, or electrical conductors. This understanding has been crucial for developing technologies incorporating carbon nanotubes, such as batteries, coatings, and resins.

Her structural analysis and early experiments, reconstructed by later scientists, have enabled advanced technologies in aerospace, defense, battery technology, and medicine (e.g., drug delivery, tissue scaffolding), demonstrating the adaptability of these carbon nanomaterials.

Legacy and Lessons

Dresselhaus was known for her problem-solving skills and willingness to tackle difficult questions.

Professor Weinstock highlighted perseverance as a key takeaway from Dresselhaus's life, noting her determination to leverage opportunities and create them for others.

Mildred and her husband, Gene, fostered a collaborative and supportive research environment, extending a "research family" atmosphere to colleagues and students.