About

Professor Steven Chu is the William R. Kenan Professor of Physics, of Molecular and Cellular Physiology, and of Energy Science and Engineering at Stanford University. The page indicates his association with Stanford and his roles across multiple departments, highlighting his interdisciplinary expertise. His research focus involves physics, molecular and cellular physiology, and energy science and engineering, reflecting a broad engagement with fundamental scientific questions and their applications. The page does not provide detailed information about his specific research contributions, background, or career history. It primarily lists his titles, contact information, and his affiliation with the Stanford Chu Group, along with a list of current and former students and colleagues. No additional biographical or research content is included in the provided text.

Research topics

• Materials science
• Chemistry
• Medicine
• Environmental science
• Pulp and paper industry
• Composite material
• Biology
• Physical chemistry
• Mathematics
• Neuroscience
• Chromatography
• Engineering
• Nanotechnology
• Geology
• Waste management
• Organic chemistry
• Inorganic chemistry
• Oceanography
• Chemical engineering
• Anatomy
• Genetics

Selected publications

• Dynamics of Radiation Damage Buildup in Ultrathin Hexagonal Boron Nitride Films under Ion Bombardment

  ACS Applied Materials & Interfaces · 2026-05-04

  articleOpen access

  Two-dimensional hexagonal boron nitride (hBN) is attractive for several emerging applications. Ion bombardment can be used to modify the hBN properties. However, the understanding of radiation damage buildup in hBN remains limited. Here, we investigate the effects of the dose rate and ion mass on radiation damage buildup by studying 40 nm-thick hBN films bombarded at room temperature with 500 keV 4He, 15N, 40Ar, and 129Xe ions and comparing with results for ion bombardment of polycrystalline hBN ceramics. Raman spectroscopy is used to quantify damage buildup, and transmission electron microscopy is used for microstructural analysis. Experiments are complemented by molecular dynamics simulations of the formation and evolution of point defects. Lighter ions are found to be more efficient at disordering hBN than heavier ions. This observation points to a critical role of intracascade defect processes. In contrast, a negligible dose rate effect observed suggests limited intercascade defect dynamic annealing processes for these irradiation conditions. These findings provide a fundamental basis for hBN defect engineering.

  PublisherDOI

• Exploring the Feasibility of the Creyos Cognitive Assessment Tool Among Patients With Heart Failure

  Cureus · 2025-11-18

  articleOpen access

  Objective The objective of this study is to explore the feasibility of the Creyos Cognitive Assessment Tool (Creyos, Toronto, Canada) as a cognitive testing instrument for patients with heart failure (HF). Background Identifying appropriate methods for cognitive testing among patients with HF is important to enable further study of their high prevalence of cognitive decline. Methods A total of 40 participants, composed of 30 outpatients with HF (75%) and 10 patients without HF (25%), were asked to complete all 12 online Creyos tests, which collectively measure short-term memory (STM), reasoning, concentration, and verbal ability. The participants had the option to complete the study at home or in person at the hospital if they did not have computer/tablet access. We explored completion rate and completion time and evaluated how our participants compared to a sex/age-matched healthy population (obtained from Creyos). Results Among 45 patients who consented to participate, five withdrew, and 40 (89%; median age: 68 {interquartile range (IQR): 59-76} years; 78% men) completed all 12 tests of cognition. Overall, the participants had a positive experience with the tool, with a median time for completion of 25.9 minutes. When compared to age- and sex-matched norms, 73% of participants with HF showed marked impairment (>1.5 standard deviations {SDs}), and 93% showed mild impairment (>1 standard deviation) on at least one test. Individuals with HF performed worse on the reasoning and verbal ability domains but better on the STM domain when compared to the age/sex-matched healthy population data provided by Creyos. Conclusion It is feasible to use Creyos as a cognitive assessment tool in the population with HF, and it may enable further exploration of the connections between cognitive function and heart failure.

  PublisherOA PDFDOI

• Topology optimization for stiffened panels considering postbuckling

  2025-08-20

  book-chapter1st authorCorresponding

  Size and shape optimisation has long been studied to maximise the critical buckling load whilst reducing the mass of stiffened panels used extensively in the structures and aerospace sectors. Moving into the postbuckling regime, where this is stable, provides the opportunity to further reduce weight and material usage, increasingly important in decarbonisation and the achievement of net zero. This study introduces topology optimization for the postbuckling of stiffened panels. A level set-based topology optimization parameterization, previously applied to linear buckling optimization, is extended to postbuckling optimization. The thicknesses of both the skin and stiffeners, stiffener layout and internal topologies are simultaneously optimized. Stiffened panels under force loading are considered for optimization. The Newton-Raphson scheme with load control is used for postbuckling analysis, where a small imperfection in the form of the first linear buckling mode is imposed on the finite element model. Two possibilities are explored – maximising load-carrying capacity and minimising out-of-plane skin deformation. Sensitivity information is shown, and a gradient-based optimizer is used to solve the optimization problems. A numerical example is used to demonstrate the application of the proposed method to postbuckling optimization of stiffened panels and highlight differences from linear buckling optimization.

  PublisherDOI

• Association Between the Emergency Heart Failure Mortality Risk Grade (EHMRG30-ST) and Costs of Care

  CJC Open · 2025-11-12

  articleOpen access

  Background: The Emergency Heart Failure Mortality Risk Grade (EHMRG30-ST) is a clinically validated model that predicts 30-day mortality in heart failure patients presenting to the emergency department (ED). However, the relationship between the EHMRG30-ST score and costs of care remains unclear. In this study, we explored the relationship between the EHMRG30-ST score and costs of care at 90 and 365 days after the index ED visit, and identified predictors of costs at 90 days. Methods: We combined 2 chart review databases, including 11,407 patients presenting to the ED with heart failure between 2004-2007. We estimated the costs from administrative databases. We stratified patients into quintiles (Q) of EHMRG30-ST scores (Q1 = lowest risk; Q5 = highest risk), and compared the total costs in 2021 Canadian dollars at 90 and 365 days by score quintiles. We further examined the cost breakdown by categories. Finally, we used a generalized linear model to identify predictors of 90-day costs. Results: < 0.0001). A positive correlation between EHMRG30-ST risk quintile and cost was observed for subcategories of hospital costs, long-term-care, and home care. Major predictors of 90-day costs were ejection fraction measurement and troponin levels. Conclusions: Higher mortality risk as determined by the EHMRG30-ST score was associated with higher costs for up to 1 year after the initial ED presentation. Our study suggests that costs of care may be another potential dimension of the utility of prognostic risk scores.

  PublisherOA PDFDOI

• Spectroscopy of Individual Ion in Liquid Environments

  ECS Meeting Abstracts · 2025-11-24

  articleSenior author

  Understanding individual ions in solution is critical to advancing our knowledge of complex chemical systems; however, detecting and tracking ions at the single-ion level in liquid environments remains challenging. Here, we present a novel strategy to visualize and differentiate ions in liquids using optically active point defects in hexagonal boron nitride (h-BN) as sensitive ion sensors. Interactions between ions and these point defects alter their emission properties, enabling real-time detection and visualization of single ions. Using Li+ ions in organic electrolytes as a demonstration, we observed spectral shifts exceeding 10 nm upon addition of Li+, and over 50 nm under applied electric fields, attributed to interactions between Li+ and h-BN defects. We further successfully differentiated multiple ion types (Na+, Zn2+, Al3+) in aqueous solutions. Each ion’s unique electronic structure induces characteristic spectroscopic signatures upon interaction with h-BN defects. This sensing approach enables direct, spectroscopic visualization and differentiation of single ions, providing valuable insights into ion dynamics and chemical reactions. The platform holds significant potential for diverse applications in battery technologies, environmental monitoring, and beyond.

  PublisherDOI

• Damage buildup in multilayer hexagonal boron nitride films under Ar ion bombardment

  Scripta Materialia · 2025-05-15 · 1 citations

  article
  PublisherDOI

• Epitaxial Electrodeposition of Fe with Controlled In-Plane Variants for Reversible Metal Anode in Aqueous Electrolyte

  ArXiv.org · 2025-10-13

  preprintOpen access

  The development of reversible metal anodes is a key challenge for advancing aqueous battery technologies, particularly for scalable and safe stationary energy storage applications. Here we demonstrate a strategy to realize epitaxial electrodeposition of iron (Fe) on single-crystal copper (Cu) substrates in aqueous electrolytes. We compare the electrodeposition behavior of Fe on polycrystalline and single-crystalline Cu substrates, revealing that the latter enables highly uniform, dense, and crystallographically aligned Fe growth. Comprehensive electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) analysis confirms the formation of Fe with specific out-of-plane and in-plane orientations, including well-defined rotational variants. Our findings highlight that epitaxial electrodeposition of Fe can suppress dendritic growth and significantly enhance Coulombic efficiency during plating/stripping cycles. This approach bridges fundamental crystallography with practical electrochemical performance, providing a pathway toward high-efficiency aqueous batteries utilizing Earth-abundant materials.

  PublisherOA PDFDOI

• Ligand-dependent G protein dynamics underlying opioid signaling efficacy

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-07-01 · 2 citations

  preprintOpen access

  Activation of heterotrimeric G proteins by G protein-coupled receptors (GPCRs) requires large-scale opening of the Gα α-helical domain (AHD) to expose the nucleotide-binding site and facilitate GDP-GTP exchange. While orthosteric ligands are known to modulate GPCR conformation and signaling efficacy, how these effects propagate to the G protein itself remains unclear. Using single-molecule fluorescence resonance energy transfer (smFRET) imaging, we monitored AHD motions in Gi proteins coupled to the μ-opioid receptor (μOR) across a spectrum of ligand- and nucleotide-bound states. We find that receptor ligands differentially modulate these dynamics from over 70 angstrom away, with higher-efficacy agonists more effectively promoting transitions to an open, low-nucleotide-affinity conformation. These data also capture transient μOR-Gi intermediates during nucleotide binding and suggest that μ-opioid ligand efficacy arises in part from allosteric control over G protein conformational equilibria that kinetically gate activation.

  PublisherOA PDFDOI

• Topology optimization for stiffened panels considering postbuckling

  2025-08-07

  book-chapter1st authorCorresponding

  Size and shape optimization has long been studied to maximize the critical buckling load whilst reducing the mass of stiffened panels used extensively in the structures and aerospace sectors. Moving into the postbuckling regime, where this is stable, provides the opportunity to further reduce weight and material usage, increasingly important in decarbonisation and the achievement of net zero. With the opportunities further extended by the use of topology optimisation and novel manufacturing techniques such as additive manufacturing we are no longer limited to prismatic stiffened panel structures, further expanding the design space for lightweight structures. This study introduces topology optimization for the postbuckling of stiffened panels. A level-set based topology optimization parameterization, which has been successfully applied to linear buckling optimization, is extended to postbuckling optimization. The thicknesses of both the skin and stiffeners, as well as the stiffener layout and internal topologies are simultaneously optimized. Stiffened panels under force loading are considered for optimization. The Newton-Raphson scheme with load control is used for postbuckling analysis, where a small imperfection in the form of the first linear buckling mode is imposed on the finite element model. Two possibilities are explored – maximizing load-carrying capacity and minimizing out-of-plane skin deformation. Two optimization formulations, respectively considering these two postbuckling metrics are studied. Sensitivity information is shown, and a gradient-based optimizer is used to solve the optimization problems. A numerical example is used to demonstrate the application of the proposed method to postbuckling optimization of stiffened panels and highlight differences from linear buckling optimization.

  PublisherDOI

• Nanometer-resolution tracking of single cargo reveals dynein motor mechanisms

  Nature Chemical Biology · 2024-08-01 · 26 citations

  articleOpen accessSenior author

  Cytoplasmic dynein is essential for intracellular transport. Despite extensive in vitro characterizations, how the dynein motors transport vesicles by processive steps in live cells remains unclear. To dissect the molecular mechanisms of dynein, we develop optical probes that enable long-term single-particle tracking in live cells with high spatiotemporal resolution. We find that the number of active dynein motors transporting cargo switches stochastically between one and five dynein motors during long-range transport in neuronal axons. Our very bright optical probes allow the observation of individual molecular steps. Strikingly, these measurements reveal that the dwell times between steps are controlled by two temperature-dependent rate constants in which two ATP molecules are hydrolyzed sequentially during each dynein step. Thus, our observations uncover a previously unknown chemomechanical cycle of dynein-mediated cargo transport in living cells.

  PublisherOA PDFDOI

Recent grants

• NIH Grant P01CA112181

  NIH · $4.0M · 2011

• NIH Grant P01GM066275

  NIH · $25.1M · 2020

• Noninvasive deep-tissue single-cell imaging and nanoprobe development

  NIH · $1.6M · 2018–2023

• Noninvasive deep-tissue single-cell imaging and nanoprobe development

  NIH · $550k · 2018–2022

Frequent coauthors

• Yi Cui

  Stanford University

  62 shared

• Axel T. Brünger

  Stanford University

  55 shared

• Holger Müller

  44 shared

• Harold D. Kim

  Georgia Institute of Technology

  42 shared

• Yan‐Kai Tzeng

  41 shared

• G. M. Ter–Akopian

  Joint Institute for Nuclear Research

  38 shared

• M. A. Stoyer

  Lawrence Livermore National Laboratory

  37 shared

• Adam de la Zerda

  Stanford University

  35 shared

Labs

• The Chu GroupPI

Education

• B.S., Mathematics

  University of Rochester

• B.S., Physics

  University of Rochester

• Ph.D., Physics

  University of California, Berkeley

Awards & honors

• 1997 Nobel Prize for laser cooling and optical trapping of a…