About

Jungwoo Lee is an Associate Professor in the Department of Chemical and Biomolecular Engineering at UMass Amherst. His research focuses on developing 3D micro-physiological and implantable tissue-engineered trabecular bone marrow models to better understand its development, homeostasis, aging, and metastasis. He is also the Departmental Honors Coordinator and an adjunct in Biomedical Engineering, contributing to the advancement of tissue engineering and regenerative medicine through his work on bone marrow models.

Research topics

• Computer Science
• Materials science
• Nanotechnology
• Soil science
• Optoelectronics
• Chemistry
• Ecology
• Environmental science
• Composite material
• Physics
• Biology
• Engineering
• Environmental chemistry
• Mechanics
• Biological system
• Mechanical engineering

Selected publications

• Mechanical Hybridization and Strengthening Mechanisms of Bimetallic Nanolamellae Architectures at Ultrahigh-Strain Rates

  SSRN Electronic Journal · 2026-01-01

  preprintOpen accessSenior author
  PublisherDOI

• Ultrahigh-Strain-Rate Mechanical Properties of Polystyrene near the Glass Transition Temperature

  Applied Sciences · 2025-06-13

  articleOpen accessSenior authorCorresponding

  Elastoplastic and tribological characteristics of polystyrene are investigated as a model glassy polymer at the ultrahigh-strain rate (>106 s −1) through the temperature-controlled laser-induced particle impact testing (LIPIT) technique. Polystyrene (PS) microparticles with a diameter of 44 µm are subjected to collisions on a rigid surface at speeds ranging from 200 to 600 m s−1, while the temperature is systematically varied between room temperature and 140 °C. Utilizing the flight path and rebound motion measured from 45-degree angled LIPIT experiments, the coefficients of restitution and dynamic friction are quantified with vectorial analysis. The onset of inelasticity can be possible at a temperature substantially lower than Tg due to the early onset of crazing dominance. While temperature- and velocity-dependent coefficients of friction suggest that the activated surface of PS can facilitate the consolidation of PS microparticles, the enhancement effect is expected more profoundly when the temperature exceeds the glass transition temperature. The microscopic ballistic approach with controlled temperature demonstrates its capability of systematically evaluating the temperature effects on various inelastic deformation mechanisms of polymers at the ultrahigh-strain-rate regime.

  PublisherOA PDFDOI

• Dynamic and Mechanochromic Responses of 3D Photonic Nanostructures Subjected to Subsonic Impact

  ChemRxiv · 2025-08-14

  articleSenior author

  High-strain-rate mechanical sensors are crucial for detecting and mitigating damage in extreme environments, thereby enabling the development of effective protection strategies. However, it remains a significant challenge due to the complicated nature of extreme mechanical stimuli. In this study, we present a passive optical sensor based on polymeric inverse opal photonic nanostructures that exhibits high sensitivity to optical responses during high-strain-rate deformation. Using laser-induced projectile impact testing (LIPIT) and nanoindentation, we evaluated polyurethane-based inverse opals fabricated with periodically ordered air pores (with diameters of 370 nm and 510 nm) to investigate their strain-dependent optical responses under both dynamic and quasi-static loading conditions. Impact energy density, energy absorptance, profilometry, and reflectance/colorimetry mapping revealed three distinct deformation regimes—compact shock, shear-induced plasticity, and uniaxial compression. These deformations produced characteristic photonic bandgap shifts and color changes in the Lab color space, which are visualized using colorimetric profiles. The colorimetric profiles reveal micron-scale deformation patterns and strain gradients across impact craters. In contrast to conventional mechanochromic systems that rely on bond rupture or molecular changes, the polymeric inverse opals respond through immediate, reversible photonic bandgap shifts caused by structural deformation. Thus, this physical nanoscale mechanism enables real-time, high-resolution sensing, outperforming chemical systems at low to moderate impact velocities.

  PublisherDOI

• Impact and Adhesion Mechanics of Block Copolymers in Cold Spray: Effects of Rubbery Domain Content

  Journal of Thermal Spray Technology · 2024-07-11 · 3 citations

  articleOpen access

  Abstract The impact and adhesion mechanics of two-phase block copolymers during high-velocity impacts are studied experimentally and computationally to understand the effect of the rubbery phase on bonding behavior in cold spray additive manufacturing. Micron-scale (10-20 μm) spherical particles of polystyrene-block-polydimethylsiloxane with varying rubbery phases are impacted on a silicon substrate by using a laser-induced projectile impact test setup with impact velocities in the range of 50-600 m/s. Experiments indicate that the minimum impact velocity for polymer particles adhering to the substrate decreases with increasing rubbery phase content. A strain rate- and temperature-dependent constitutive model and cohesive zone model are calibrated for each material by comparing the deformed and computed deformed particle shapes and coefficient of restitution values of the rebounding particles. Computational results show that increasing the rubbery phase content in block copolymers increases plastic energy dissipation from 89 to 96% and the critical strain energy release rate from 1.87 to 9.3 J/m 2 at 140 m/s, and thus contributes to the observed decrease in the minimum impact velocity required for block copolymers to adhere to substrates. The discovered direct relationship between soft phase content and critical strain energy release rate implies that increased soft-rubbery PDMS content in block copolymers enhances adhesion through improved chain mobility, better surface asperities coverage, and enhanced wetting, due to its lower surface energy and greater adiabatic heating.

  PublisherOA PDFDOI

• Enhanced mechanical energy absorption via localized viscoplasticity of nano-cellular polymer coating under supersonic impact loading

  Giant · 2023-07-20 · 7 citations

  articleOpen accessSenior authorCorresponding

  Materials under viscoplastic deformation at ultrahigh strain rates (>10[6] s−1) often demonstrate anomalous properties due to thermal and stress localization. As a model system, thermoplastic nano-cellular material (NCM) coatings are produced by consolidating microscopic polystyrene shells of nanoscale thin walls using self-limiting electrospray deposition. As both the spatial and temporal characterization scales are crucial, the NCMs are characterized by laser-induced projectile impact test (LIPIT) for understanding their ultrahigh-strain-rate plasticity originating from their porous structures. In LIPIT, supersonic collisions of rigid microspheres create these extreme physical conditions at the microscale. Viscoplastic vertical densification without the Poisson effect is the foremost process in the ultrahigh-rate plastic deformation of the NCM coatings. When the extreme nature of the viscoplastic deformation is promoted by increasing the porosity and reducing the thickness of NCM coatings, significantly more energy dissipation is observed without more material due to the localized feedback between adiabatic plastic deformation and thermal softening. Despite the stochastic and isotropic structural architecture of the NCM, the specific energy absorption of the NCM is high as 170 kJ/kg at the deformation speed of 400 m/s, which is attributed to the nanoscale effects from the thin wall thickness of NCM coatings. The findings suggest the general design rule for enhancing specific energy absorption by creating viscoplastic hot spots under impact loading.

  PublisherDOI

• Extreme Plasticity, Adhesion, and Nanostructural Changes of Diblock Copolymer Microparticles in Cold Spray Additive Manufacturing

  ACS Applied Polymer Materials · 2023-08-18 · 7 citations

  articleSenior authorCorresponding

  Using the laser-induced projectile impact testing (LIPIT), the extreme plastic and adhesive responses of polystyrene-polydimethylsiloxane block copolymer (BCP) microparticles are investigated to provide the ultra-high-strain-rate behavior of individual BCP feedstock powders during their collisions with a stationary substrate in the cold spray additive manufacturing process. The onset of BCP microparticle adhesion to the substrate is precisely predicted by the maximum coefficient of dynamic friction, quantified from the angled collisions, and by the spectra of the coefficients of restitution. This finding confirms the direct correlation between friction and adhesion mechanisms in the ultra-high-strain rate regime and its significance in the consolidation process of BCP feedstock powders. Furthermore, the impact-induced adiabatic shear flows create structural ordering of initially disordered nanostructures of the block copolymers consisting of glassy and rubbery domains while generating a temperature rise beyond their glass transition temperatures. In addition to the conventional strain-hardening effect in homopolymers, nanoscale morphological ordering can provide another strain-hardening mechanism of BCP feedstock microparticles in the cold spray of additive manufacturing.

  PublisherDOI

• Impact and adhesion mechanics of block copolymer micro-particles with a silicon substrate

  Mechanics of Materials · 2023-10-04 · 4 citations

  article
  PublisherDOI

• Non-Destructive Measurement of Optically Scattering Polymer Films Using Image Processing

  ChemRxiv · 2023-07-19 · 2 citations

  preprintOpen access

  We establish a sample- and data-processing pipeline that allows for high-throughput measurement optical microscope measurement of porous films, provided that the film is sufficiently optically scattering. Here, self-limiting electrospray deposition (SLED) is used to manufacture scattering films of different morphologies. This technique compensates for the scattering of the films through background subtraction of the reflection image with the transmission image. This process is implemented through a combination ImageJ-MATLAB data pipeline; the Canny edge-detector is used as the image-processing algorithm to identify boundaries of the film. We verify this process against manually measured images; a comparative study between cross-sectional scanning electron microscopy (where scattering effects are diminished) and optical microscopy also verifies that our optical microscopy technique can be used to consistently, non-destructively measure film thickness regardless of film morphology. In addition, this technique can be used in combination with dense film measurements to measure film porosity.

  PublisherOA PDFDOI

• On adiabatic shear instability in impacts of micron-scale Al-6061 particles with sapphire and Al-6061 substrates

  International Journal of Plasticity · 2023-05-11 · 22 citations

  article
  PublisherDOI

• <scp>Non‐destructive</scp> thickness measurement of optically scattering polymer films using image processing

  Engineering Reports · 2023-12-25 · 1 citations

  articleOpen access

  Abstract We establish a sample‐ and data‐processing pipeline that allows for high‐throughput optical microscope measurement of porous films, provided they are sufficiently optically scattering. Here, self‐limiting electrospray deposition (SLED) is used to manufacture scattering films of different morphologies. This technique compensates for the scattering of the films through background subtraction of the reflection image with the transmission image. This process is implemented through a combination of an ImageJ and MATLAB data pipeline; the Canny edge‐detector is used as the image‐processing algorithm to identify the boundaries of the film. This process is verified against manually measured images; a comparative study between cross‐sectional scanning electron microscopy (where scattering effects are diminished) and optical microscopy also verifies that our optical microscopy technique can be used to consistently, non‐destructively measure film thickness regardless of film morphology. In addition, this technique can be used in combination with dense film measurements to measure film porosity.

  PublisherOA PDFDOI

Recent grants

• Collaborative Research: Multi-Scale Micromechanical Properties of Hierarchical Coatings and Interfaces Fabricated by Self-Limiting Electrospray Deposition

  NSF · $312k · 2020–2025

• Collaborative Research: High-Strain-Rate Dynamics of Copolymer Microparticles for Advanced Additive Manufacturing

  NSF · $312k · 2018–2022

Frequent coauthors

• Edwin L. Thomas

  Texas A&M University

  74 shared

• Kai‐Ming Ho

  Iowa State University

  54 shared

• Kristen Constant

  Iowa State University

  46 shared

• Steven E. Kooi

  Institute for Soldier Nanotechnologies

  46 shared

• Keith A. Nelson

  40 shared

• David Veysset

  Stanford University

  40 shared

• Mostafa Hassani

  39 shared

• Kyu-Heon Kim

  National Institute of Food and Drug Safety Evaluation

  20 shared

Education

• PhD, Physics

  Iowa State University

  2006

Awards & honors

• Junior Faculty Award (CoE UMass-Amherst) 2020
• CAREER Award (NSF) 2020
• Early Career Investigator Award (METAvivor Foundation) 2020
• KIChE President Young Investigator Award, 2019
• K99/R00 Pathway to Independence Award (NCI) 2012