2015 to 2022 Director, of the Berkeley Nanosciences and Nanoengineering Institute (BNNI), an umbrella organization for expanding and coordinating Berkeley research and educational activities in nanoscale science and engineering. Zettl has advised approximately 50 graduate students (including those earning Ph.D. degrees in chemistry, mechanical engineering, electrical engineering, and materials science), and approximately 40 postdoctoral researchers. Selected research accomplishments Access to Zettl’s 600+ research publications, supplementary materials, and research highlights can be found at https://www.ocf.berkeley.edu/~jode/index.html. Charge density wave statics and nonlinear dynamics Zettl discovered chaotic response and period doubling routes to chaos in dynamic charge density wave (CDW) systems driven by an rf field, and found that mode locking completely freezes out all internal fluctuations of the collective mode condensate. He identified phase slip centers as the origin of so-called switching in CDWs. He discovered unusual electro-elastic coupling in CDW systems, and studied the evolution of the CDW order parameter as sample sizes approached the nm scale. For the 2D static CDW system TaS2, Zettl used cryogenic STM measurements to fully characterize domain structure, and to contrast bulk CDW parameters determined via x-ray scattering to surface CDW parameters established by STM. High temperature superconductors and fullerenes Zettl performed seminal isotope effect measurements in high temperature superconductors, including substituting oxygen, barium, and copper isotopes in Y-Ba-Cu-O, substituting oxygen isotopes in La-Sr-Cu-O, and substituting carbon and alkali isotopes in A3C60. These measurements placed severe constraints on the superconductivity mechanism, and revealed that superconductivity in the copper oxides was likely not phonon-mediated, but likely was phonon mediated in the fullerenes. Zettl was the first to intercalate high-Tc superconductors with foreign molecules which allowed Cu-O planes to be physically and electronically separated. Zettl also produced high quality single crystals of fullerene superconductors which facilitated a host of detailed transport and thermodynamic measurements. Zettl revealed the elastic properties of high-Tc materials, and determined the effective dimensionality of fullerene superconductors via paraconductivity measurements. Carbon and boron nitride nanotubes and related nanostructures Zettl has performed extensive studies on the mechanical and electronic properties of carbon nanotubes (CNTs). He created electronic devices from CNTs, including a rectifier and chemical sensor. From thermal conductivity measurements he extracted the linear-T behavior expected from the quantum of thermal conductance. He created a highly robust CNT-based electron field emission source. Zettl discovered that CNTs could be stable in a fully collapsed state, which led to a refined quantification of the interlayer interaction energy