About

Huajian Gao is the Walter H. Annenberg Professor Emeritus of Engineering at Brown University. His research interests include the nanomechanics of engineering and biological systems. Gao has been recognized for his contributions to the field, with recent honors including being named among the top two percent of scientists in the world and receiving the George Irwin Gold Medal award from the International Conference on Fracture. His work focuses on understanding the mechanical behavior at the nanoscale, contributing to advancements in engineering and biological systems.

Research topics

• Materials science
• Engineering
• Computer Science
• Nanotechnology
• Composite material
• Physical chemistry
• Risk analysis (engineering)
• Business
• Systems engineering
• Crystallography
• Engineering management
• Mathematics
• Data science
• Forensic engineering
• Metallurgy
• Chemistry
• Geometry

Selected publications

• From paradigm to practice: MechanoEngineering in the Mechano-X era

  MechanoEngineering · 2026-04-27

  article1st authorCorresponding
  PublisherDOI

• Force-regulated catch bonds and fusion peptide exposure drive coronavirus entry

  bioRxiv (Cold Spring Harbor Laboratory) · 2026-05-22

  articleSenior author

  Coronaviruses invade human cells within dynamic mechanical environments through endocytosis and membrane fusion, both mediated by the class I fusion protein spike. In SARS-CoV and SARS-CoV-2, the spike engages the human ACE2 receptor through a catch bond--an interaction whose lifetime increases under tensile force. Concurrently, mechanical pulling facilitates disruption of the S1/S2 subunits of spike, a critical step for membrane fusion. To elucidate how mechanical cues coordinate these processes, we developed a unified elastic-stochastic model that integrates theoretical analysis and computational simulations to trace viral entry. Our results identify the force-regulated catch bond between spike and ACE2 as a key determinant of successful invasion. This catch bond not only enhances receptor-mediated endocytosis but also increases the probability of S1/S2 disengagement, thereby promoting membrane fusion. Importantly, under conditions of strong catch bonding, the force-accelerated separation of S1 and S2 fine-tunes the balance between entry pathways. These findings uncover a potential mechanobiological mechanism that mediates viral cell entry by coupling receptor binding strength with spike disassembly under force. By characterizing these mechanical regulations, this work facilitates the assessment of emerging viral threats and inspires the design of drug delivery systems that leverage catch-bond kinetics for enhanced targeting.

  PublisherDOI

• Explicit Geometry Optimization of Cohesive Interfaces: Mechanics, Sensitivities, and the Emergence of Interlocking

  SSRN Electronic Journal · 2026-01-01

  preprintOpen accessSenior author
  PublisherDOI

• Ultrapliable bioelectronic interface for mechanosensitive cardiac electrophysiology

  Science Advances · 2026-01-07 · 1 citations

  articleOpen accessCorresponding

  Existing bioelectronics often exhibit megapascal-scale moduli, despite the mechanosensitive nature of cardiomyocytes. Bridging the mechanical mismatch between tissue and bioelectronics is indispensable for building physiologically relevant in vitro cardiac models and advancing therapies. Here, we present Pliable Ultrathin Layered Sensing Electronics (PULSE), a platform with tissue-matched modulus (~10 kilopascals) and stretchable gold microcircuitry for long-term, high-fidelity monitoring of cardiac electrophysiology in vitro. Composed of a soft gel matrix and an ultrathin nanofilm embedded with gold circuits, our device achieves unprecedented tissue integration and preserves natural cardiomyocyte mechanics, resulting in a 140% increase in mechanical contraction and a 100% increase in electrical signals compared to conventional electronics. Cardiac tissue that grows our device exhibited enhanced drug sensitivity and response in cardiac dysfunction, revolutionizing disease modeling. By facilitating seamless interaction at the tissue-electronic interface, our platform offers a transformative perspective for advancing cardiac modeling and next-generation bioelectronic applications.

  PublisherDOI

• A structural disorder function linking local symmetry breaking to plastic indicators and strength in amorphous solids

  Proceedings of the National Academy of Sciences · 2026-02-27

  articleOpen accessSenior authorCorresponding

  Establishing intrinsic structure–property relationships in amorphous solids remains a central challenge in materials science because the absence of long-range order obscures universal structural descriptors. Here, we introduce a structural disorder function, S d ( r ), as a physically interpretable and quantitative metric for atomic-scale disorder in amorphous systems. S d ( r ) is formulated as the magnitude of the normalized vector sum from a reference atom to its neighbors within different radial shells, thereby capturing local symmetry breaking analogous in concept to the Burgers vector in crystals. Molecular dynamics simulations across diverse amorphous alloys and glasses, together with colloidal-glass experiments, demonstrate that S d ( r ) correlates meaningfully (correlation coefficient &gt; 0.68) with key particle-scale plastic properties, including vibrational mean-square displacement, flexibility volume, atomic stiffness, and vibrational frequency. Liquid-like regions consistently exhibit higher S d ( r ) values than solid-like ones, revealing its ability to distinguish mechanical heterogeneity. When averaged over the field, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mfenced close="〉" open="〈"> <mml:mrow> <mml:msub> <mml:mi>S</mml:mi> <mml:mi mathvariant="normal">d</mml:mi> </mml:msub> </mml:mrow> </mml:mfenced> </mml:math> monotonically increases with cooling rate and exhibits a universal negative linear relationship with shear strength, τ p = A – B <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mfenced close="〉" open="〈"> <mml:mrow> <mml:msub> <mml:mi>S</mml:mi> <mml:mi mathvariant="normal">d</mml:mi> </mml:msub> </mml:mrow> </mml:mfenced> </mml:math> , quantitatively linking structural disorder to macroscopic strength. These results establish S d ( r ) as a simple, dimensionless, and broadly applicable descriptor that unifies atomic configuration, processing history, and mechanical response in disordered materials, providing a physics-based framework for the rational design of amorphous solids.

  PublisherDOI

• Mechanically active polymeric adhesives (MAPAs) for tissue regeneration

  Progress in Materials Science · 2026-01-16 · 2 citations

  articleOpen access
  PublisherOA PDFDOI

• Self-constructed functional anode for sulfide all-solid-state lithium batteries with ultrahigh critical current density

  eScience Energy · 2026-04-01

  articleOpen access

  This work develops a self-constructed functional alloy anode for high-performance all-solid-state lithium batteries (ASSLBs). We designed a (200)-oriented single-phase Li/Na alloy using a controlled weight ratio (0.1:0.9) and a cold-rolling process, with enhanced air stability. When assembled with sulfide solid electrolytes, the Li 0.1 Na 0.9 alloy anode would self-construct into tri-layer functional structures: an in situ formed Na 2 S interfacial layer from the reaction between Na and the electrolyte, to suppress the leakage of electrons at the interface; a self-precipitated Li layer, facilitated by the special orientation, to offer nuclei for the uniform deposition of lithium; and a self-formed Na buffer layer to dynamically regulate the stress during the deposition process. This new anode enables the critical current density of symmetrical cells to exceed 12.74 mA·cm −2 at room temperature, sustaining stable cycling for over 1580 h at 10.19 mA·cm −2 , with the cell-level energy density expected to exceed 450 Wh·kg −1 . We anticipate that this finding will have an immediate impact on the next generation of ASSLBs. • A single-phase Li 0.1 Na 0.9 alloy anode with dominant (200) orientation is fabricated via a facile cold-rolling process and ratio control. • It spontaneously self-constructs a tri-layer functional structure with Na 2 S interfacial layer, Li metal layer and remaining Na buffer in sulfide ASSLBs, addressing interfacial instability. • The anode achieves an ultrahigh critical current density of 12.74 mA·cm −2 and stable cycling over 1580 h at 10.19 mA·cm −2 . • A 70 μm-thick lightweight alloy anode enables a cell-level energy density exceeding 450 Wh·kg −1 , suitable for scalable applications.

  PublisherDOI

• Mechano-X: A paradigm for mechanics-based interdisciplinary innovation

  MechanoEngineering · 2026-01-06 · 5 citations

  articleOpen accessSenior author

  Mechanics has historically been a cornerstone of modern science and technology, serving as a vital bridge between science and engineering. In the current era of rapid technological advance, mechanics faces unprecedented challenges and opportunities that demand a paradigm shift in its intellectual framework. Here, we introduce the Mechano-X paradigm—a forward-looking vision for mechanics-based interdisciplinary innovation. In this paradigm, mechanics is not merely a descriptive tool, but an active driver that deeply integrates with other scientific disciplines, enabling the controlled regulation, programming, and optimization of target systems in fields such as materials science, chemistry, biology, and medicine. This proactive integration has already catalyzed transformative fields such as mechanobiology, mechanochemistry, and mechanomaterials. By enabling the design of materials and systems with unprecedented forms, functions, and responsiveness, Mechano-X fosters deep cross-disciplinary convergence. We argue that this integrative approach reaffirms mechanics as a core scientific force, uniquely positioned to inspire the next generation of scientific discovery and technological innovation.

  PublisherDOI

• Strong and brittle lithium dendrites

  Science · 2026-03-12 · 3 citations

  articleCorresponding

  The growth and penetration of lithium dendrites through electrolytes and separators remain key challenges to realizing high-energy density lithium-metal batteries. Using mechanically strong electrolytes and separators has been considered a promising strategy based on the commonly believed softness of lithium. However, dendrite formation persists in stiff solid electrolytes, suggesting distinct mechanical behaviors. We measured the mechanical properties of individual lithium dendrites using an air-free protocol. We found that lithium dendrites are unexpectedly strong and brittle, with fracture stress greater than ~150 megapascals, unlike the ductile bulk metal. Cryo-transmission electron microscopy and mechanical modeling showed that this behavior arises from solid electrolyte interface constraints and nanoscale strengthening. These findings provide alternative mechanisms for dendrite penetration and dead lithium formation as well as guidance for design strategies for lithium-metal batteries.

  PublisherDOI

• Nanoporosity-driven deformation of additively manufactured nano-architected metals

  Nature Communications · 2026-02-28

  articleOpen access

  3D printing methods for small-scale metals enable a unique 10–100 nm dimensional niche where functional feature sizes, critical microstructural detail and atomic-level defects converge, challenging conventional hierarchical relationships and carrying significant nanomechanical implications. We introduce a metal nano-printing system combining two-photon lithography, hydrogel infusion-based additive manufacturing and in situ mechanical experiments on 3D nano-architected Ni, achieving ~100 nm critical dimensions, ~10 nm surface roughness, and a broad range of geometries (periodic vs. non-periodic; beam-based vs. shell-based) with superior specific strengths of ~100 MPa·g − 1·cm3 enabled by an unambiguous smaller is stronger size effect. Experiments identify concentrated-porosity regions as primary deformation-initiation sources and quantify their distribution as input for physics-informed, multiscale finite-element simulations that accurately predict size-dependent mechanical properties governed by nanoporosity-driven deformation. This work integrates experimental and computational approaches for the fabrication, characterization, and evaluation of nano- and micro-architected metals for nanotechnology and nanoscale manufacturing systems. A two-photon-lithography hydrogel-infusion process prints 3D nickel nano-architectures with ~100-nm features and high specific strength, indicating that localized nanoporosity hotspots govern deformation and size-dependent strength.

  PublisherOA PDFDOI

Recent grants

• LCE: Computational Methods for Mechanism-Based Higher-Order Continuum Theories

  NSF · $211k · 1999–2004

• Topological Design of Tough Multi-functional 2D Materials

  NSF · $400k · 2016–2020

• Multiscale Mechanics of Cell Interactions With Flexible Nanofilaments

  NSF · $459k · 2016–2019

• Effects of Elasticity and Geometry on Cellular Uptake of Nanoparticles

  NSF · $381k · 2010–2015

• Deformation, Strength, Fatigue and Fracture of Gradient Nanostructured Metals

  NSF · $479k · 2017–2021

Frequent coauthors

• Brian W. Sheldon

  152 shared

• Guijin Zou

  Nanyang Technological University

  127 shared

• Xiaoyan Li

  126 shared

• Markus J. Buehler

  119 shared

• Christos E. Athanasiou

  Providence College

  107 shared

• Xinghua Shi

  100 shared

• Xi‐Qiao Feng

  98 shared

• Yong‐Wei Zhang

  Anqing City Hospital

  87 shared

Labs

• Nanomechanics of Engineering and Biological SystemsPI

Education

• PhD, Division of Applied Science

  Harvard University

  1988

• B.S., Engineering Mechanics

  Xi'an Jiaotong University

  1982

Awards & honors

• George Irwin Gold Medal awardees by International Conference…