About

Seong Kim is the Department Head and Walter L. Robb Family Endowed Chair in Chemical Engineering at Penn State University. His research focuses on energy and environment, interfaces and surfaces, with specific interest areas including tribology, glass surface science, and cellulosic nanomaterials. His work involves surface science, nano-materials, nano-tribology, glass, biomass, and catalysis. He has authored books such as 'Surface and Interface Analysis: Principles and Applications' and 'Adhesion aspects in MEMS/NEMS'. His extensive publication record includes numerous journal articles on topics like surface chemistry, nanomaterials, glass-water interactions, and tribology, contributing significantly to understanding surface phenomena, nanostructured materials, and their applications in energy, environmental science, and materials engineering.

Research topics

• Materials science
• Organic chemistry
• Chemistry
• Composite material
• Engineering
• Optoelectronics
• Biochemistry
• Computer Science
• Chemical physics
• Nanotechnology
• Biology
• Chemical engineering
• Artificial Intelligence
• Data science
• Environmental chemistry
• Optics
• Polymer chemistry
• Cell biology
• Physics
• Environmental science
• Biophysics
• Botany
• Mathematics
• Pulp and paper industry

Selected publications

• Polarizable Thiol–Ene Cross-Linked Nitrile Dielectrics for Stretchable Low-Voltage Neuromorphic Transistors with Acoustic Classification

  ACS Applied Materials & Interfaces · 2026-01-05 · 1 citations

  articleOpen accessCorresponding

  A stretchable, high-k dielectric material based on thiol–ene-cross-linked nitrile-butadiene rubber (NBR) for synaptic transistors is demonstrated. We investigated NBR formulations cross-linked with three thiol cross-linkers. The thiol–ene-cross-linked NBR dielectrics achieve a high dielectric constant (k = 14.6), enabling low-voltage transistor operation (<5 V) and photopatterned capability. By comparing different thiol cross-linkers, we have found that more thiol groups facilitate higher charge mobility and larger hysteresis. The thiol–ene-cross-linked NBR dielectric-based transistor exhibited superior electrical properties, including a high mobility (0.42 cm2 V–1 s–1), a high ON/OFF ratio (104), and a small threshold voltage (0.2 ± 0.4 V). More importantly, these devices effectively mimic synaptic functions. A large hysteresis, driven by dielectric polarization and enhanced by thiol introduction, was observed, particularly pronounced in NBR dielectric with multiple thiol-cross-linkers. The thiol–ene-cross-linked NBR device displayed superior short-term plasticity and long-term potentiation/depression, indicating its learning and memory capabilities. Encouragingly, the fully stretchable NBR transistor maintained good electrical performance, stable hysteresis, and essential synaptic behaviors even at 60% strain. As a practical demonstration for neuromorphic applications, the thiol–ene-cross-linked NBR device exhibited excellent acoustic classification performance, achieving recognition accuracy close to 99% even under mechanical deformation. In summary, the developed thiol–ene cross-linked NBR offers highly promising electronic properties for stretchable, low-voltage neuromorphic devices.

  PublisherDOI

• Deep learning for automated hip fracture detection and classification

  The Bone & Joint Journal · 2025-02-01 · 17 citations

  article

  Aims: The aim of this study was to develop and evaluate a deep learning-based model for classification of hip fractures to enhance diagnostic accuracy. Methods: A retrospective study used 5,168 hip anteroposterior radiographs, with 4,493 radiographs from two institutes (internal dataset) for training and 675 radiographs from another institute for validation. A convolutional neural network (CNN)-based classification model was trained on four types of hip fractures (Displaced, Valgus-impacted, Stable, and Unstable), using DAMO-YOLO for data processing and augmentation. The model's accuracy, sensitivity, specificity, Intersection over Union (IoU), and Dice coefficient were evaluated. Orthopaedic surgeons' diagnoses served as the reference standard, with comparisons made before and after artificial intelligence assistance. Results: The accuracy, sensitivity, specificity, IoU, and Dice coefficients of the model for the four fracture categories in the internal dataset were as follows: Displaced (1.0, 0.79, 1.0, 0.70, 0.82), Valgus-impacted (1.0, 0.80, 1.0, 0.70, 0.82), Stable (0.99, 0.95, 0.99, 0.83, 0.89), and Unstable (1.0, 0.98, 0.99, 0.86, 0.92), respectively. For the external validation dataset, the sensitivity and specificity were as follows: Displaced (0.83, 0.94), Valgus-impacted (0.89, 0.90), Stable (0.88, 0.95), and Unstable (0.85, 0.99), respectively. The overall means (Micro AVG and Macro AVG) for the external dataset were Micro AVG (0.83 (SD 0.05), 0.96 (SD 0.01)) and Macro AVG (0.69 (SD 0.02), 0.95 (SD 0.02)), respectively. Conclusion: Compared to human diagnosis alone, our study demonstrates that the developed model significantly improves the accuracy of detecting and classifying hip fractures. Our model has shown great potential in assisting clinicians with the accurate diagnosis and classification of hip fractures.

  PublisherDOI

• Vibrational Sum Frequency Generation Spectroscopy Study of Nanoscale to Mesoscale Polarity and Orientation of Crystalline Biopolymers in Natural Materials

  Annual Review of Physical Chemistry · 2025-02-19 · 5 citations

  reviewOpen accessSenior author

  As a nonlinear optical process, sum frequency generation (SFG) requires noncentrosymmetry across multiple length scales, ranging from individual molecular functional groups to their arrangements in space. This principle makes SFG not only intrinsically sensitive to molecular species at surfaces but also useful for studying 3D structures of crystalline biopolymers in natural materials. Examples of such biopolymers are cellulose, starch, and chitin in the polysaccharide family and collagen, silk, and keratin in the fibrous protein family. These biopolymers are noncentrosymmetric at multiple length scales, with chirality at the molecular scale, unit cell structure at the nanoscale, and crystallite orientation and polarity at the mesoscale; thus, they are SFG active. In this review, we describe how SFG can be used to determine nano- to mesoscale polarity and orientational orders of crystalline biopolymers interspersed in natural materials containing the same or similar biopolymers in amorphous states, which cannot be obtained with other characterization methods.

  PublisherDOI

• Mechanochemical wear of soda lime silicate glass in water: Effect of cations in aqueous solution

  Journal of the American Ceramic Society · 2025-07-16

  articleCorresponding

  Abstract Surface flaws and defects of glass are known to be sensitive to the environment to which the glass surface is exposed. Previous investigations indicated that the mechanochemical wear of soda lime silicate (SLS) glass in humid air is associated with the presence of sodium ion leaching and interactions with adsorbed water, but the wear of SLS glass in aqueous solutions remains elusive. In this study, the wear of SLS glass was investigated in aqueous solutions with the presence of various electrolyte cation sizes and valences. The results show that the mechanochemical wear of SLS glass decreases as the concentration of sodium ions in the aqueous solution increases. However, the mechanochemical wear of the SLS glass surface increases with the ion size for solutions with monovalent cations, but significantly decreases with the di‐ and trivalent cations in aqueous solutions. Further analyzes indicate that the sodium ion migration to the glass surface plays important roles in mechanochemical wear of SLS glass in aqueous solutions, in addition to the ion‐exchange and hydrolysis of Si–O–Si network. The findings of this study provide further insights into the mechanochemical damage mechanism of silicate glass in aqueous environments.

  PublisherDOI

• On the structural role of indium in aluminoborosilicate glasses: A multi-spectroscopic study

  Acta Materialia · 2025-10-24 · 2 citations

  article
  PublisherDOI

• Piezoelectric DC Generator Through Sequential In‐Phase Polarization Variation

  Advanced Energy Materials · 2025-08-29 · 2 citations

  articleOpen access

  Abstract Energy harvesting has drawn growing interest as a reliable power source for IoT applications, with piezoelectric materials notable for their high sensitivity and straightforward integration. Their robust mechanical‐electrical coupling also makes them ideal for harnessing environmental vibrations or mechanical motions. Still, standard piezoelectric harvesters inherently produce alternating current (AC), necessitating complex rectification steps and leading to substantial energy loss. This work introduces a direct current (DC) harvesting method that employs a novel in‐phase polarization strategy, enabling a stable, continuous DC output. This approach surpasses prior attempts that offered only low or pulsed DC signals, achieving an open‐circuit voltage of 33.44 V and a short‐circuit current of 3.72 mA with a size of 7.5 cm 2 . A prototype generator demonstrated a maximum power output of 29.73 mW. Moreover, this design is both miniaturizable and scalable, broadening its potential deployment across diverse sectors. Its practical value was exemplified by directly powering CO 2 electrolysis, where it achieveds a Faradaic efficiency of 86.22%, underscoring the method's ability to circumvent AC‐based inefficiencies and pave the way for more effective, sustainable energy solutions.

  PublisherOA PDFDOI

• Impact of B and Al on the initial and residual dissolution rate of alumino-boro-silicate glasses. Part II: gel properties

  npj Materials Degradation · 2025-05-22 · 3 citations

  articleOpen accessSenior author

  Physical and chemical properties of passivating alteration gels formed on alumino-boro-silicate glasses of interest for nuclear waste containment are reported. Opposite effects of B and Al on the gel’s propensity to restructure and become passivating were observed. Boron, primarily forming Si‒O‒B bonds, fragments and weakens the silicate network if its concentration is higher than a critical value, leading to the formation of pores and Si‒OH terminations as it leaches out. The greater the number of the silanol groups, the more effective the recondensation (Si‒OH + Si‒OH ⇌ Si‒O‒Si + H2O) is, leading to reduction of pore connectivity; this facilitates passivation and thus lowers the glass alteration rate. Conversely, Al has a slowing effect on this reorganization dynamics. This work provides better insight into the role of elements in the glass alteration kinetics.

  PublisherOA PDFDOI

• Long-cycling lithium-metal batteries via an integrated solid–electrolyte interphase promoted by a progressive dual-passivation coating

  Nature Energy · 2025-06-26 · 22 citations

  article
  PublisherDOI

• Dual‐Functional High‐Entropy Polymer Exhibiting Giant Cross‐Energy Couplings at Low Fields

  Small Science · 2025-02-22 · 11 citations

  articleOpen access

  A key component of cooling devices is the transfer of entropy from the cold load to heat sink. An electrocaloric (EC) polymer capable of generating both large electrocaloric effect (ECE) and substantial electroactuation can enable EC cooling devices to pump heat without external mechanisms, resulting in compact designs and enhanced efficiency. However, achieving both high ECE and significant electroactuation remains challenging. Herein, it is demonstrated that poly(vinylidene fluoride‐trifluoroethylene‐chlorofluoroethylene‐double bond) [P(VDF‐TrFE‐CFE‐DB)] tetrapolymers can simultaneously generate high electrocaloric effects and electroactuations under low fields. These P(VDF‐TrFE‐CFE‐DB) tetrapolymers are synthesized through the dehydrochlorination of P(VDF‐TrFE‐CFE) terpolymer. By facile tuning the composition of the initial terpolymer to avoid pure relaxor state, tetrapolymers with optimal DB compositions are achieved, near the critical endpoint of normal ferroelectric phase with diffused phase transition. The nearly vanishing energy barriers between the nonpolar to polar phases result in a strong electrocaloric response and significant electroactuation. Specifically, the P(VDF‐TrFE‐CFE‐DB) tetrapolymer exhibits an EC entropy change Δ S of 100 J kg −1 K −1 under 100 MV m −1 : comparable to state‐of‐the‐art (SOA) EC polymers, while delivering nearly twice the electroactuation of the SOA EC polymers. This work presents a general strategy for developing EC materials that combine large electrocaloric effect and electroactuation at low electric fields.

  PublisherOA PDFDOI

• Toward Superlubricity of Amorphous Carbons: Friction of Thermally-Produced Carbon and Diamond-Like Carbon

  Tribology Letters · 2025-07-03 · 2 citations

  articleOpen accessSenior author

  Abstract Amorphous carbons can have drastically different physical properties depending on synthetic methods. Among these, hydrogenated diamond-like carbon (HDLC) produced via plasma-enhanced chemical vapor deposition is unique in that it exhibits superlubricity with a coefficient of friction (COF) less than 0.01 in proper environmental conditions. It is known that HDLC undergoes friction-induced graphitization at the shear interface and forms a highly hydrogenated transfer film at the counter-surface sliding against it. In contrast, glassy carbon (GC) produced via pyrolysis of organic precursors rarely exhibits superlubricious behavior even though the graphitic nature probed with Raman spectroscopy is similar to that of the transfer film formed from HDLC. This study addresses this drastic difference in friction of HDLC and GC and identifies key parameters that can be tuned to achieve (nearly) superlubricious behaviors with GC. The factors influencing the superlubricity of amorphous carbon include the composition and structure of the initial carbon coating, which strongly depend on the synthetic method, and the coating failure and transfer film stability, which depend on the surface chemistry of the substrate.

  PublisherOA PDFDOI

Recent grants

• Mechanochemistry of Silicate Glass Surface: Mixed Modifier Effect on Resistance to Frictional Subsurface Damage

  NSF · $480k · 2020–2024

• Lubrication by Chemical Reaction Products at Sliding Interface

  NSF · $350k · 2014–2018

• COLLABORATIVE RESEARCH EAGER: Sum-frequency generation (SFG) vibration study of structure and enzymatic hydrolysis activities of crystalline cellulose in biomass

  NSF · $50k · 2011–2013

• Fundamental Mechanisms for Mechanochemical Behaviors of Glass Surfaces - An Integrated Experimental and Computational Approach

  NSF · $608k · 2016–2020

• Collaborative Research: Understanding Run-In and Superlubricity of Diamond-Like Carbon Coatings from a Tribochemical Perspective

  NSF · $398k · 2019–2023

Frequent coauthors

• Stéṕhane Gin

  Commissariat à l'Énergie Atomique et aux Énergies Alternatives

  49 shared

• Hongtu He

  43 shared

• Linmao Qian

  Southwest Jiaotong University

  37 shared

• Yassine Haddab

  Laboratoire d'Informatique, de Robotique et de Microélectronique de Montpellier

  37 shared

• Yann Le Gorrec

  Centre National de la Recherche Scientifique

  37 shared

• V. J. Logeeswaran

  36 shared

• Nicolas Lafitte

  Fluigent (France)

  36 shared

• Avinash P. Nayak

  36 shared

Education

• PhD, Chemistry

  Northwestern University

  1998

• MS, Chemistry

  Yonsei University

  1992

• BS, Chemistry

  Yonsei University

  1990

Awards & honors

• Outstanding Engineering Alumni Award
• Early Career Alumni Recognition Award
• Alumni Achievement Award
• Alumni Fellow Award