Honors & Awards
John and Kate Wakerly Stanford Graduate Fellowship, Stanford University
Education & Certifications
MS, Stanford University, Electrical Engineering (2019)
B.Sc., University of Alberta, Electrical Engineering (2016)
Thermoelectric response from grain boundaries and lattice distortions in crystalline gold devices.
Proceedings of the National Academy of Sciences of the United States of America
The electronic Seebeck response in a conductor involves the energy-dependent mean free path of the charge carriers and is affected by crystal structure, scattering from boundaries and defects, and strain. Previous photothermoelectric (PTE) studies have suggested that the thermoelectric properties of polycrystalline metal nanowires are related to grain structure, although direct evidence linking crystal microstructure to the PTE response is difficult to elucidate. Here, we show that room temperature scanning PTE measurements are sensitive probes that can detect subtle changes in the local Seebeck coefficient of gold tied to the underlying defects and strain that mediate crystal deformation. This connection is revealed through a combination of scanning PTE and electron microscopy measurements of single-crystal and bicrystal gold microscale devices. Unexpectedly, the photovoltage maps strongly correlate with gradually varying crystallographic misorientations detected by electron backscatter diffraction. The effects of individual grain boundaries and differing grain orientations on the PTE signal are minimal. This scanning PTE technique shows promise for identifying minor structural distortions in nanoscale materials and devices.
View details for DOI 10.1073/pnas.2002284117
View details for PubMedID 32900922
- 3D Electromagnetic Reconfiguration Enabled by Soft Continuum Robots IEEE ROBOTICS AND AUTOMATION LETTERS 2020; 5 (2): 1704–11
High-Throughput Growth of Microscale Gold Bicrystals for Single-Grain-Boundary Studies.
Advanced materials (Deerfield Beach, Fla.)
The study of grain boundaries is the foundation to understanding many of the intrinsic physical properties of bulk metals. Here, the preparation of microscale thin-film gold bicrystals, using rapid melt growth, is presented as a model system for studies of single grain boundaries. This material platform utilizes standard fabrication tools and supports the high-yield growth of thousands of bicrystals per wafer, each containing a grain boundary with a unique <111> tilt character. The crystal growth dynamics of the gold grains in each bicrystal are mediated by platinum gradients, which originate from the gold-platinum seeds responsible for gold crystal nucleation. This crystallization mechanism leads to a decoupling between crystal nucleation and crystal growth, and it ensures that the grain boundaries form at the middle of the gold microstructures and possess a uniform distribution of misorientation angles. It is envisioned that these bicrystals will enable the systematic study of the electrical, optical, chemical, thermal, and mechanical properties of individual grain boundary types.
View details for DOI 10.1002/adma.201902189
View details for PubMedID 31197897
- A Tip-Extending Soft Robot Enables Reconfigurable and Deployable Antennas IEEE ROBOTICS AND AUTOMATION LETTERS 2018; 3 (2): 949–56